GT4 Dampers

[sucahyo]

....Hmmm, If I was to remove a damper from a car that had been set to "10" I would imagine it would be hard for me to compress, compared to say a damper that had been set to "1" - If I was to then drive a car with Dampers set to 10 through a slalom on smooth tarmac I would imagine it would respond to steering inputs quite quickly and drive quite good, I would imagine a car with soft damping would respond slower and be more "sluggish" as you term it, however the car with damping set softer would handle better on a bumpy circuit in my experience.

I will try in a test what I just mentioned to confirm my theory.👍

Ok .
About slow response, I recently tune Falken GT-R to make it drift. Using all 10 make the car react slowly, making me spin easier, countersteer is more difficult. By using 1 damper at front I feel the steering is more direct. As it increase car reaction, I consider this is a proof that 1 is stiffer.

damaged shocks act in an unpredictable manner and as such you can't assign particular handling characteristics to them in comparison to a functioning damper.

Then, explain what unpredictable behaviour that may occur on non functioning damper.

I was illustrating my point with real world examples.

I am saying that you use wrong example. That example do not illustrate the effect of too soft damper like I believe (or my reference mention). Manufacturer isn't that stupid. And even 15 years old car damper can still dampening small bump, although 25 years old car may not (noisy cabin, Brrrrrt brrrrt brrrrtt, etc).

No, softer dampers will only allow more up and down movement if the spring rate allows it.

I mean it as longer time too, what the exact word that I should use for longer time movement? I don't say it compress/expand more.

In my own Celica I have experienced loss of traction from a wheel losing contact with the road when driving hard over a poor road. I've driven the same road in a more softly damper car and not lost tyre contact with the road at similar speeds.
However according to you I must be imagening this, as it does not 'fit' with your belief of how dampers work.

No, I believe that. I will assume that the damper is too hard too. It is the same behaviour as http://wotid.com/tls/content/view/22/53/ link. So I think you feel pack down, squat, chatter, stiff and thaught as well. And you NOT feel sloppy and wallow on corner. From my view I say you feel like flying through bump.

you mean apart from the quotes I have already supplied over the pages of this thread and others on the subject.

It is because the quote do not contain the word "unstable", since you mentioning it few time when you use 10 damper on stiff spring in GT4. You even mention it in your guide: "From here I then start with the rebound rate, test drive the car, if it feels unstable, bouncy and loose then increase the rebound rate." You already know the correct treatment, I will do this too. But I believe unstable is from damper too soft fault, not too stiff. Loose, I believe also the sign of too soft damper.

What I mean is do you have reference for too stiff is unstable or too soft is more stable?

Only one quote you may say. Yes, but in this instance its quality not quantity, the Skip Barber race school and it instructors and techs wrote the Going Faster race guide. It is considered one of the world definative texts on racing. It quite clearly states that too still dampers on a bumpy track will lead to a loss of tyre contact withthe road, and as it sayd tyres that are not in contact with the road don't provide much grip.

One quote I mean is from my own quote, the http://wotid.com/tls/content/view/22/53/ link. It say both too soft and too hard make the car unstable. Your quote do not count since it does not mentioning anything about unstable.

A car that can't provide grip is not going to be particularly stable.

Your quote do not specifically saying this. In other word, it does not say that too stiff is unstable.

It would also appear that my own experience on training this subject is being dismissed by you. So in a similar vein to your question earlier, may I ask what experience you have in this field?

Don't have any. But I think it's possible for anyone to make mistake. And your mistake is not your real life knowledge, but only on this game understanding.

Have you played Richard Burns Rally?

No.

If so, then fine that is your opinion. If not please explain what exactly you are basing that statement on, because RBR allows damper settings that are far to soft for the car.

After hugh bump and landing, what is maximum count of hopping happen? If it exceed 10 then I say it allow too soft damper. It is about 3 in GT2 (damper 10), 5 in GT1 (damper 1), 5 in NFS Porsche edition.

Also I said that damping will slow down the cycle in comparison to a totaly undamped spring.

Ok.

I'm sorry but did you deliberatly ignore the fact that I said I would have to test this before I commented?

No, I just want to hear your first opinion before you test it, just based from what you already know. Or you can comment on why I experience this:
my previous 10/1 and 1/10 turn out to have opposite effect than what I expected. It slows the Audi R8 nose up, not down like I previously predict. But it still reduce the nodding in one way. Using 10/10 10/10 damper the R8 would nodd heavily. And I must confess that even though I am using this when making 356mph Audi R8 (currently fastest on 300mph club , I am not sure if it help me reach it.

So now only spring rate has an effect?

No, because the spring is too soft, differentiating not so different low and high value would be harder. So I don't compare FC and stock. But I think comparing car looseness using softest FC would be appropriate.
And this remind me, you agree that higher damper value make the car loose right? (mentioned in your tuning guide too). Are you saying stiffer damper make real life car feel more loose too?
Are you saying your celica feel more loose compare to normal road car?

Damping values are very, very different between stock cars and cars with FC fitted. Try the car I mentioned and see if you still think damper values are unchanged.

Ok, I will test this on my next chance.

Since when? All damper manufacturers use guides of there own, normally so many 'clicks' up and down from a zero point, not a 1 to 10 scale.

I based on this

The dial rotates through 90° or 180°, and is calibrated on a scale from 1 to 10. Usually, the higher the number, the greater the resistance to impact. Adjustment generally is made by observing energy absorption at different settings

I closing I have to say that your reply here has actually ignored a lot of what I said in my post and you seem to be happy to dismiss out of hand any evidence that does not support what you believe should be correct.

Forgive me, I doesn't mean that. I will try to use game tuning as evidence next.

You seem to totally dismiss the fact that a car can lose control is dampers are set too firmly for a bumpy track!! State that the firmer you set a damper the more stable a car will be (which is true on a perfect track - but few tracks are perfect) which again is not always true.

No, I am aware that car can loose control, but unstable is different from loosing control. What I mean is:
Car with adequate damping will be most stable, too soft or too stiff can make it loose control, but too soft will be most unstable.

I have maintained all along that too soft or too hard dampers will cause a problem, I also have said that a correct 'middle' point is needed to tune a car for a track.

Yes, and I think GT4 only provide tuning from correct "middle" (damper 1) to too soft (damper 10). From your point of view GT4 only provide tuning from correct "middle" (damper 1) to too stiff (damper 10).

I base my view that lower is soft on a wide range of evidence and experience (not all trawled from the web), I do have to ask exactly what expereince you have in the real world of driving different cars, on different dampers to dismiss out of hand my own perspective.

I am not saying your real life experience is wrong, but I am saying your view for GT4 damper is wrong.
Let's not use bump for testing, let's use body roll or weight transfer. If you take a heavy car with 4/4 spring rate, which damper setting will make the car handle more sharp/more direct/less lazy on consecutive corner:
1/1 1/1 damper
or
10/10 10/10 damper

Since I consider 1 is stiffest then I will choose 1. Since you consider 10 is stiffest then you presumably choose 10.
Is this correct or not? And which one of us is right?

If you choose 1 although being softest, explain the reason please.

 

[Dave_George]

Ok .
About slow response, I recently tune Falken GT-R to make it drift. Using all 10 make the car react slowly, making me spin easier, countersteer is more difficult. By using 1 damper at front I feel the steering is more direct. As it increase car reaction, I consider this is a proof that 1 is stiffer.

Hi Sucahyo,

I will test the Falken GTR later this afternoon and post you my thoughts on this matter:tup:

I would like to add that you have mentioned several times in your last post the you believe Scaff's knowledge of GT4 to be incorrect.

I will make no secret of the fact Im a big fan of Scaff, his resource and knowledge in my opinion seem second to none, his tuning guides are professional, unbiased and make sense to even a novice attempting to tune a car in GT4.

I for one trust what he says regarding GT4 AND real life tuning issues, and I feel you are wrong in what you have said about his GT4 knowledge.

You seem to make this thread ever more complicated unnesessarily and I must admit I am lost as to where its going now....

To go back to the original thread title "Damper 10 is softer than 1" - I think that is incorrect. The settings in GT4 go from 1 to 10 and in my experience based on my own tuning and joint efforts with Scaff during the NRS race series lower settings allowed the car to hold the road better, higher settings created a more unstable car, indicating to me that lower settings are softer and higher settings are stiffer, a concept I think that for me at least seems fairly easy to grasp.

regards

David

 

[Mt. Lynx]

No, you still don't have proof/reference about damper too stiff can make the car unstable.And even with cheap material manufacturer surely prevent car unstability from too soft damper.

Aside from this link I found another link explaining that car is unstable if using damper too soft.


irrelevant link but show how to tune damper


Only 1 of them mention unstability cause by damper too stiff , majority say it's damper too soft fault.
I'll wait for your reference.

This is because in racing, cornering is one of the most important aspects. And stiff damping allows for better cornering abilities, so soft settings are ignored to some extent, as straightline stabilty over bumps is less important than cornering speed.

Softer is not too soft. If you use 5% of that softer damper, you will experience it.

More stable doesn't mean more softer.
To correct slow steering response / snap which do you prefer:
10/1 10/1 or 1/10 1/10

I choose the later one. This works for me, I am thinking that snapping is reduced because front have stiffer damper and make it tighter.

Well, depends on what car you refer to. A FR car, the first one. MR or RR, the latter. And for the exact same reason you mension.

No. I experience both in my bike. Are you saying car suspension can't experience it? Are you saying that the same type of damper will work differently if it's used in car?
I don't understand your logic why too soft can't have rapid cycle, or no damping can't have slow cycle. If the road force it to do that what happen then? Too soft is not the same as road car soft. If soft damper can't have rapid cycle then it is NOT too soft.

Yes, damping WILL work differently on a car!
Of course a no-damping situation can have rapid cycles, but depends on speed mainly. The faster you go, the more violent the movement will become. Eventually, such a setup will loose contact with the surface, but a solid setup would loose contact sooner, and with a more spectacular bang too.

So you can't explain why nodding is reduce when damper is lowered?

No, that does not happen in my cars! A damper value of 1/1 1/1 will nod more than a set of 10/10 10/10, but the 10/10 will vibrate much more and cause erratic behaviour, especially during the turn, wich tells me that 1/1 is soft (more nodding) and 10/10 is hard (vibrations)

We have to wait for proof that too stiff damper indeed make the car unstable, I found more reference told that it is too soft damper behaviour.

What do mean, proof?? Lets again take a stroll to world of racing, where stiff settings, as I said earlier, are more important than soft. However, a too hard setup, can do damage to the suspension, the chassis, and it may cause spinouts, bad understeer on cold tyres, and may be too violent vibrations for the driver to handle. In racing though, these are all calculated risks, as a stiffer setting overall is better than a soft one. These are all well known facts of racing, and nothing I just came up with for fun.

I am sure that you feel all lowest damper have faster reaction than all highest one right? I feel all highest more sluggy at slalom. How do you feel about this? And you view about what make it behave like this?

My feel tell me the exact opposite to your feel. But this may also be, that a softer damper value, gives you more slalom efficiancy, if the springs are set correctly. And in slalom, stabilisers has to be an important part to account for.
And now, do you know how a damper works? (you most likely do, but you dont think this is replicated in GT4) Have you held one in your hands, and compressed it? With a slow movement, you can compress it by hand, but try compressing it by force, and the resistance in the damper is too great. This is done so the damper can work pretty much in the same way, no matter what speed you travel in. Now, an originally hard damper, like on a racing car, will of course react with tremendeous force at speed, and may be so stiff, that the car will jump when encountering a bump, quite well recreated in GT4, like Scaff pointed out with the BTCC/Honda Integra pictures. All signs point to high value = stiff!

 

[Scaff]

Then, explain what unpredictable behaviour that may occur on non functioning damper.

The use of the word unpredictable should indicate to you that its not possible to predict how a damaged damper will react. In fact you provided a link that had a chart on it showing how a damaged damper can react in a totally unpredictable manner.

It’s a bit strange that you should need to ask the question of me, when you posted the link that answers the very question?

It is because the quote do not contain the word "unstable", since you mentioning it few time when you use 10 damper on stiff spring in GT4. You even mention it in your guide: "From here I then start with the rebound rate, test drive the car, if it feels unstable, bouncy and loose then increase the rebound rate." You already know the correct treatment, I will do this too. But I believe unstable is from damper too soft fault, not too stiff. Loose, I believe also the sign of too soft damper.

What I mean is do you have reference for too stiff is unstable or too soft is more stable?

One quote I mean is from my own quote, the http://wotid.com/tls/content/view/22/53/ link. It say both too soft and too hard make the car unstable. Your quote do not count since it does not mentioning anything about unstable.

Your quote do not specifically saying this. In other word, it does not say that too stiff is unstable.

I’m sorry but your attitude on this one really is starting to get very annoying. You dismiss a piece on how dampers react to bumps, written by one of the worlds finest race driving instructors, based on the fact that it does not contain a specific word you insist should be in it.

That is just ludicrous. A car can be described as unstable through both under and over damping, I have never said anything but this, you however have been disputing that instability can be caused by over stiff damping.

The piece I quoted quite clearly says:

Tires that spend half their time in the air don't provide much grip. Expect that the shock settings for bumpy racetracks will have to be softer in order to allow the suspension to move fast enough to keep the tires in contact with the track surface.

Now I am very sorry that the word ‘unstable’ is not used specifically, but its absence is irrelevant. A car that is unable to maintain contact with the track surface (as is clearly being described here) is quite clearly not going to be stable.

Now please either accept that a car that is not in contact with road through dampers being too stiff to react is ‘unstable’ or explain how a car in this condition would be stable.

By the way you may be happy to dismiss the Skip Barber quotes I use, but I believe they carry more weight than any quote from an internet linked source (and I am more than aware of the irony of saying that in an internet forum). The Skip Barber book has been used and reviewed by almost every racing body and magazine in the world, the Internet on the other hand is hardly the most accurate source of information.

I strongly advice you buy and read Going Faster before you continue to dismiss it out of hand.


Edited to add - Schumacher's crash in todays Australian GP clearly demonstrated this, he ran wide onto the grass and hit a nasty bump, the resulting loss of tyre contact with the surface unsettled the car so much he lost control and hit the barrier. Sounds like a fairly unstable situation to me.

Don't have any. But I think it's possible for anyone to make mistake. And your mistake is not your real life knowledge, but only on this game understanding.

Then I would ask why you have been (and continue to) question my real world understanding and my ability to read a cars behaviour?

You are right that one of us is wrong here, however that person could be you!

After hugh bump and landing, what is maximum count of hopping happen? If it exceed 10 then I say it allow too soft damper. It is about 3 in GT2 (damper 10), 5 in GT1 (damper 1), 5 in NFS Porsche edition.

This is in reference to Richard Burns Rally, a game you have no experience with.

The damping in RBR can be set so low that you do not need a bump to start the spring oscillations, simple weight transfer from steering will do it. That’s true under-damping.

And this remind me, you agree that higher damper value make the car loose right? (mentioned in your tuning guide too). Are you saying stiffer damper make real life car feel more loose too?
Are you saying your celica feel more loose compare to normal road car?

No I do not agree that higher damper makes a car feel loose (but that does depend on what you mean by loose. Nor do I say that in my guide.

From here I then start with the rebound rate, test drive the car, if it feels unstable, bouncy and loose then increase the rebound rate.

Is exactly what my guide says, lower values (softer) make the car feel looser, increasing the value (making it firmer) reduces this.

And no I would not describe my Celica as ‘loose’, it feels tight and firm under weight transfer, sometimes to much so, particularly over very bumpy roads (but you seem to believe that makes it stable – which it’s damn well not under these conditions).

No, I am aware that car can loose control, but unstable is different from loosing control. What I mean is:
Car with adequate damping will be most stable, too soft or too stiff can make it loose control, but too soft will be most unstable.

Define unstable?

To me (as I have already described) a car that is so stiff that it loses tyre contact with the road surface could be described as unstable,

Would this be more or less stable than the same car with soft damping? Well that depends on the car and the road, if the road was very smooth then it may be more stable, but if the road was very bumpy then it may well be less stable.

Yes, and I think GT4 only provide tuning from correct "middle" (damper 1) to too soft (damper 10). From your point of view GT4 only provide tuning from correct "middle" (damper 1) to too stiff (damper 10).

From every bit of real world experience I have I can safely say that GT4 dampers (FC) can not be described as being too soft.

I am not saying your real life experience is wrong, but I am saying your view for GT4 damper is wrong.
Let's not use bump for testing, let's use body roll or weight transfer. If you take a heavy car with 4/4 spring rate, which damper setting will make the car handle more sharp/more direct/less lazy on consecutive corner:
1/1 1/1 damper
or
10/10 10/10 damper

Since I consider 1 is stiffest then I will choose 1. Since you consider 10 is stiffest then you presumably choose 10.
Is this correct or not? And which one of us is right?

If you choose 1 although being softest, explain the reason please.

Of the two values on offer I would (and I have just tested this) go for 10. A firmer setting (as long as the track is smooth) would allow a slower onset of under and oversteer as the slower reaction of the damper speeds up the transfer of weight to and from the tyres contact patch.

This does however cause the issue that it can cause a ‘snappy’ feel once the limit has been reached.

Softer values have the opposite effect, the faster reaction of the damper allows the time the load is transferred to and from the tyres contact patch to be slowed, this can cause a more rapid onset of under and/or over steer, but can help reduce the snappy feel.

Its why the ‘middle’ point that is right for the car, driver and track is the sweet spot, as I have maintained all along.

n.b - please note that the snappy feel can be caused by a number of situaltions and damper settings can help, but will not always remove or reduce the problem.

More stable doesn't mean more softer.
To correct slow steering response / snap which do you prefer:
10/1 10/1 or 1/10 1/10

I choose the later one. This works for me, I am thinking that snapping is reduced because front have stiffer damper and make it tighter.

I do love the slight conflict you have put your suspension in with the second set of values.

Imagine your car is braking and the front goes into bound and the rear goes into rebound.

The low front value (which I consider soft) allows a rapid reaction from the suspension, however your rear high rebound value (stiff in my book) is fighting to slow this. Which one will be dominant will depend on the car, its weight distribution and the load under transfer.

So which one will work best, well that depends on the car and the track and the driver, personally I would rarely work with settings that extreme, but that’s just me as a driver.


In regard to all of this I have carried out a few tests with a Challenger RT, equiped with FC suspension and with the springs set to the lowest value and the ride height jacked all the way up.

Dampers 1/1 1/1
Car feels soft
More visible roll under gear change, acceleration and braking.
Rapid transfer to under/oversteer


Dampers 10/10 10/10
Car feels harder, more skittering over rumble strips and grass
Slower body roll under gear change, acceleration and braking.
Slower transition to under/oversteer, but far more snappy once it occurs.


Now all the above match ‘real world’ observations for low being soft and high being firm, but he following was more interesting.

Dampers 1/10 10/1
This set up caused a rapid suspension reaction on braking (forward weight transfer – front in bound & rear in rebound) and a slower return (front in rebound & rear in bound).

Reversing these settings (so 10/1 and 1/10) resulted in the opposite effect, again pointing to low being softer and high being firmer.


Regards

Scaff

 

[sucahyo]

My reason for damper 10 is softer
- On 255 damper GT4 Skyline GTS-T Type M will wave up and down infinitely, but I am hesitate to post the video because it may insult PCSX2 people (very low quality) or it maybe a banned material in GTPlanet. I can give step by step procedure if anyone want to recreate this, camber location is 2 byte before 4 byte of ride height.
- On bump car will vibrate more on higher value
- After jump the car will bounce / waving up and down more on higher value
- Car reaction feel more stiff on lower value
- 300mph car nodding is reduced on low value

I will test the Falken GTR later this afternoon and post you my thoughts on this matter

Ok, I will happily accept any comment .

I for one trust what he says regarding GT4 AND real life tuning issues, and I feel you are wrong in what you have said about his GT4 knowledge.

Ok. I guess I am the only one that think 10 damper is softer, higher camber is slippier in corner, tranny trick is faster, etc. And it is funny that even though I don't have GT4, I am the one that create https://www.gtplanet.net/guides/index.php/Gran_Turismo_4_:_Tuning and contribute 80% of it.

The settings in GT4 go from 1 to 10 and in my experience based on my own tuning and joint efforts with Scaff during the NRS race series lower settings allowed the car to hold the road better, higher settings created a more unstable car, indicating to me that lower settings are softer and higher settings are stiffer, a concept I think that for me at least seems fairly easy to grasp.

I agree that lower setting hold the road better too, but for me it indicate to me that 10 is too soft. As I say, I think damper setting range from too soft to medium. Your opinion show you think damper range from medium to too stiff.

And stiff damping allows for better cornering abilities, so soft settings are ignored to some extent, as straightline stabilty over bumps is less important than cornering speed.

I prefer to call stiff as medium or just right.

Well, depends on what car you refer to. A FR car, the first one. MR or RR, the latter. And for the exact same reason you mension.

You are right.

Yes, damping WILL work differently on a car!

I don't agree. Even if the car have more than damper and spring in its suspension. the way it works should be the same. The damper rate will increase if the moving speed (frequency) increase.

No, that does not happen in my cars!

I mean to say that the nose rise become slower, and nose down not affected when using 10/1 1/10.

as a stiffer setting overall is better than a soft one.

Ok.

My feel tell me the exact opposite to your feel. But this may also be, that a softer damper value, gives you more slalom efficiancy, if the springs are set correctly.

Never thought of that.

And now, do you know how a damper works? (you most likely do, but you dont think this is replicated in GT4) Have you held one in your hands, and compressed it? With a slow movement, you can compress it by hand, but try compressing it by force, and the resistance in the damper is too great.

Yes, the damping resistance increase as the speed increase.

Now, an originally hard damper, like on a racing car, will of course react with tremendeous force at speed, and may be so stiff, that the car will jump when encountering a bump, quite well recreated in GT4, like Scaff pointed out with the BTCC/Honda Integra pictures.

I still think that those can happen on both damper too soft and damper too stiff.

The use of the word unpredictable should indicate to you that its not possible to predict how a damaged damper will react.

I assume the unpredictability is sometimes it work sometimes it don't. Ranging from working bellow normal to non resistance at all. It also mean that I can experience too soft damper too.

A car that is unable to maintain contact with the track surface (as is clearly being described here) is quite clearly not going to be stable.

It does not explain the unstable.

explain how a car in this condition would be stable.

Maybe I use the word incorrectly again, see bellow.

The Skip Barber book has been used and reviewed by almost every racing body and magazine in the world

I am not saying it's inaccurate or unreliable, it just don't explain about damper much. No damper special edition or something like that.

Then I would ask why you have been (and continue to) question my real world understanding and my ability to read a cars behaviour?

I started to doubt your feel when you say damper behavour in GT2 & GT4 is the same as damper behaviour in GT1.

The damping in RBR can be set so low that you do not need a bump to start the spring oscillations, simple weight transfer from steering will do it. That’s true under-damping.

Ok, I assume it will be roughly the same as GT1.

No I do not agree that higher damper makes a car feel loose (but that does depend on what you mean by loose. Nor do I say that in my guide.

Yes, entirely my mistakes, sorry, I mixed up the value.

And no I would not describe my Celica as ‘loose’, it feels tight and firm under weight transfer, sometimes to much so, particularly over very bumpy roads

ok

To me (as I have already described) a car that is so stiff that it loses tyre contact with the road surface could be described as unstable,
From every bit of real world experience I have I can safely say that GT4 dampers (FC) can not be described as being too soft.

• Too hard - as a rule, if the damping is too hard, the bike will feel unstable. If it's too hard in the compression damping the suspension will not comply with bumps, as the transferring of the force is too slow, meaning the wheel will tend to skip over the top of the bumps rather than follow the contour of the road surface. If too hard in the rebound damping the bike will tend to 'pack down' or 'squat'. This is caused by the suspension not allowing the bike to rise back up to its original position quickly enough. The end result of this is sometimes referred too as suspension "chatter." Although the bike will feel unstable, it will tend to feel quite 'stiff' or 'taught.'
• Wheel hop can easily be felt by the driver and, if extreme, can be seen by those watching the race car. During wheel hop, the tire bounces up and down uncontrollably and causes the handling to be very unstable. The fix, of course, is to install stiffer shocks. Keep in mind that wheel hop to any degree, whether felt by the driver or not, reduces traction.

Which unstable description fits GT4 damping behaviour more first or second?
I think Team666 description fits the second more.

Damping is for sure at its softest at 1, as the slow jumping is at its peak right there. At 10, the car shakes and vibrates badly in over 300 mph, and furthermore, if damping is set to 1, a higher speed will be possible, than if set to 10. This is because if the damping is too hard, it will not bound/rebound in large enough portions, thus making the car erratic.

n.b - please note that the snappy feel can be caused by a number of situaltions and damper settings can help, but will not always remove or reduce the problem.

Ok.

In regard to all of this I have carried out a few tests with a Challenger RT, equiped with FC suspension and with the springs set to the lowest value and the ride height jacked all the way up.

Still 50% not sure. You can make me stop arguing if you include car waving count after jump. I think I will test heavy car on nurburg ring next.

 

[Mt. Lynx]

@ Suchayo: I think you are wrong in your assumption that the dampers in GT4 ranges from soft to medium. IMO the range is very soft (1) to very stiff (10).

Too hard - as a rule, if the damping is too hard, the bike will feel unstable. If it's too hard in the compression damping the suspension will not comply with bumps, as the transferring of the force is too slow, meaning the wheel will tend to skip over the top of the bumps rather than follow the contour of the road surface. If too hard in the rebound damping the bike will tend to 'pack down' or 'squat'. This is caused by the suspension not allowing the bike to rise back up to its original position quickly enough. The end result of this is sometimes referred too as suspension "chatter." Although the bike will feel unstable, it will tend to feel quite 'stiff' or 'taught.'
Wheel hop can easily be felt by the driver and, if extreme, can be seen by those watching the race car. During wheel hop, the tire bounces up and down uncontrollably and causes the handling to be very unstable. The fix, of course, is to install stiffer shocks. Keep in mind that wheel hop to any degree, whether felt by the driver or not, reduces traction.
Which unstable description fits GT4 damping behaviour more first or second?
I think Team666 description fits the second more.

Quote:
Originally Posted by Team666
Damping is for sure at its softest at 1, as the slow jumping is at its peak right there. At 10, the car shakes and vibrates badly in over 300 mph, and furthermore, if damping is set to 1, a higher speed will be possible, than if set to 10. This is because if the damping is too hard, it will not bound/rebound in large enough portions, thus making the car erratic.

I feel this needs further explanation. The cars vibration is not caused by wheelhop, I´ve watched the wheels far too many times to say that wheelhop causes the vibration in car. It is the dampers or the springs that causes this. And as I usually have the springs set as low as possible, it has to be the dampers, whom I occasionally set higher than 1. At 10, wich IMO is very hard, the damping efficiancy is reduced to a minimum, and are IE not compressing/decompressing much at all, thus causing vibrations. On the other hand, when dampers are this stiff, nodding is reduced to an absolute minimum, and only occur very occationally, if at all.
The fact that this happens, shows - at leats to me - that 10 is very hard, in fact so hard that not even such extreme speeds as over 350 mph with full downforce will compress the dampers. That is why I sometimes use a 10/1 1/10 setting, so the damping will kind of work, but still let the car "stand up" on it´s dampers.

 

[sucahyo]

I think you are wrong in your assumption that the dampers in GT4 ranges from soft to medium. IMO the range is very soft (1) to very stiff (10).

I assume this because I can't loose traction from both direction, I can only loose traction on high value damper only, I can't loose traction even when using 0 (hacked) damper.

That is why I sometimes use a 10/1 1/10 setting, so the damping will kind of work, but still let the car "stand up" on it´s dampers.

I use that on all my 300mph cars . But for different reason, I want to make the nodding slowdown at one direction only, it turn out that the nose up is slowing down.

 

[Mt. Lynx]

Try hacking the stabilisers as well, then you will have nothing but springs to support the cars weight, or the opposit; hack the springs to 0, and the stabilisers to 0. Check dampers after that, from 0 to whatever (255?) But do you know for a fact that the hacked values will actually represent that value? If I were you, I´d try to concentrate on the actual in game values instead.

 

[Scaff]

My reason for damper 10 is softer
- On 255 damper GT4 Skyline GTS-T Type M will wave up and down infinitely, but I am hesitate to post the video because it may insult PCSX2 people (very low quality) or it maybe a banned material in GTPlanet. I can give step by step procedure if anyone want to recreate this, camber location is 2 byte before 4 byte of ride height.
- On bump car will vibrate more on higher value
- After jump the car will bounce / waving up and down more on higher value
- Car reaction feel more stiff on lower value
- 300mph car nodding is reduced on low value

Why would it be banned here at GT4?

The low quality would worry me more, but I have also expressed my concerns (as others have) about the validity of extreme value testing and to be honest its not a discussion I want to repeat over and over again.

Ok. I guess I am the only one that think 10 damper is softer, higher camber is slippier in corner, tranny trick is faster, etc. And it is funny that even though I don't have GT4, I am the one that create https://www.gtplanet.net/guides/index.php/Gran_Turismo_4_:_Tuning and contribute 80% of it.

I believe you are one of the few people (and the only one here that I know of) who believes that higher damper values are softer.

On the subject of higher camber loosing grip in corners, a number of us agreed with you (including me), we simply questioned you’re method of setting the right camber value. You prefer a visual approach, I prefer a testing based approach. I think most people agreed that extreme camber values cause problems, but that what constituted extreme will vary from car to car, track to track and driver to driver.

In regard to the ‘tranny-trick’ again some people agree with you others don’t, personally I don’t use it, but have seen good write-ups of it working in some cars and not in others. I my second guide I actually include a piece on it because so many people use it or what to know about it.

I just need to clarify a few things here, can you answer the following as yes or no

Do you own GT4?

Do you play it on a PS2?

If not do you use a PC emulator?

[enters Mod mode]As a mod here at GTP I would have to say that your answers to these are important as I would have to question your status as a GT4 guides writer if you a) don’t have GT4 or b) you only run it in a PC. Please be honest with these answers[/exit Mod mode]

I agree that lower setting hold the road better too, but for me it indicate to me that 10 is too soft. As I say, I think damper setting range from too soft to medium. Your opinion show you think damper range from medium to too stiff.

Yes my opinion and many others is that the 1 to 10 range runs from a medium-ish value to firm.

I still don’t understand how you believe that a medium setting (1 in your world) would improve you’re road holding and response over bumps compared to a soft setting (10 in your world)?

I don't agree. Even if the car have more than damper and spring in its suspension. the way it works should be the same. The damper rate will increase if the moving speed (frequency) increase.

The way a damper works is the same; that doesn’t change. However a bike just has front rear transfer as far as the dampers are concerned. Cars have four corners and left:right and front:rear transfer. The forces placed on the dampers and how they work in relation to each other is different.

I did say this previously.

I still think that those can happen on both damper too soft and damper too stiff.

Yes it can happen with very, very soft damper settings (I don’t recall saying it could not), but are you seriously trying to say that BTCC cars jump when hitting curbs because they run very soft set-ups?

Have you tried running these tests yourself?

I assume the unpredictability is sometimes it work sometimes it don't. Ranging from working bellow normal to non resistance at all. It also mean that I can experience too soft damper too.

Again I did not say you would not experience too soft damping, I said that you could not predict what damping effect you would get!!

It does not explain the unstable.

Maybe I use the word incorrectly again, see bellow.

I am not saying it's inaccurate or unreliable, it just don't explain about damper much. No damper special edition or something like that.

The point you have reached with this is now starting to make my blood boil. Have you read this book?

If not how the hell do you know what it does or does not cover on damping?

I have no intention of writing the entire book out for you, buy a copy.

It covers damper interaction (and how every force working on a car causes it to react in a given situation) and more in far more detail than any of the internet links you have provided.

In addition you have singularly failed to answer the very direct question I asked you in regard to this.

Now please either accept that a car that is not in contact with road through dampers being too stiff to react is ‘unstable’ or explain how a car in this condition would be stable.

Or explained the example I gave

Edited to add - Schumacher's crash in todays Australian GP clearly demonstrated this, he ran wide onto the grass and hit a nasty bump, the resulting loss of tyre contact with the surface unsettled the car so much he lost control and hit the barrier. Sounds like a fairly unstable situation to me.

In regard to the term 'unstable' I believe part of the problem here may come from what appears to be a very singular definition of unstable that you appear to have.

To my mind you are fixated on handling stability, which is one of the most commonly discussed areas of stability with regard to damping. This occurs because most 'road' cars on a race track will benefit from a stiffer suspension set-up (including dampers), as the average racetrack is a far smoother environment that a public road. GT4 caters for this with the increase in basic stiffness (in all areas) that comes with moving from Stock to sport to semi-racing to FC suspension. It should however always be remembered that limits do exist as to how stiff you wnat to make the damping of the car.

Now the other area of stability that needs to be considered is that of body control itself, the ability of the cars tyres to remain in contact with the track surface. This is not the same as handling stability, but is can and does effect it under certain conditions. Mainly when the track surface is bumpy. Put simply a car that can't keep its tyresin contact with the road surface loses control and therefore stabilty, now while this is not directly the handling stabilty, if you don't have all four tyres in contact with the track at all times you will effect the handling stability of the car.

Softening the dampers will help with this on bumpier tracks (note I did not say 'soft' dampers - rather softening them), as it will allow the suspension to react quicker to changes in the track surface. Yes this may well compromise the handling stability, but remember you can't have handling stabilty if your tyres are not in conatct with the road (unless you can explain how a cars handling doesn't suffer if you try and go around a corner with only three tyres in conatct with the road surface).

Why do some of your Internet links not mention this? Well to put it simply, because some of them simply are not good enough. The 'net is a useful tool, but I would never trust it as definative source of information. Most web-sites focus on direct handling benefits of dampers, mainly to make things simpler.

The single reason I use the Skip Barber book so much is that its over 250 pages of combined experience from ten instructors of the racing school and the technicians that set-up and maintain the cars.

Its level of detail and accuracy in every subject I have used it in simply is hard to beat, it is bluntly put one of the foremost reference books in motorsport.

I started to doubt your feel when you say damper behavour in GT2 & GT4 is the same as damper behaviour in GT1.

You can doubt all you like, I’m the one who sat down and did a full back to back comparison of the entire GT series as far as damping when.

All of which was done on the PS2, with a DS2. You have admitted that a lot of the testing you were doing with GT2 was done on a PC emulator using the keyboard.

I’m sorry but its your ability to read feel that I would place in doubt here, I would also seriously question your ability to compare it to real world feel encountered in a car on a track.

• Too hard - as a rule, if the damping is too hard, the bike will feel unstable. If it's too hard in the compression damping the suspension will not comply with bumps, as the transferring of the force is too slow, meaning the wheel will tend to skip over the top of the bumps rather than follow the contour of the road surface. If too hard in the rebound damping the bike will tend to 'pack down' or 'squat'. This is caused by the suspension not allowing the bike to rise back up to its original position quickly enough. The end result of this is sometimes referred too as suspension "chatter." Although the bike will feel unstable, it will tend to feel quite 'stiff' or 'taught.'
• Wheel hop can easily be felt by the driver and, if extreme, can be seen by those watching the race car. During wheel hop, the tire bounces up and down uncontrollably and causes the handling to be very unstable. The fix, of course, is to install stiffer shocks. Keep in mind that wheel hop to any degree, whether felt by the driver or not, reduces traction.

Which unstable description fits GT4 damping behaviour more first or second?
I think Team666 description fits the second more.

And I totally disagree with you, the first example is a much better match to what I have felt and seen with higher damper values. However the person to answer this one is Team666 himself.



In closing I have to say that your attitude on this one is becoming one of almost blind arrogance. Any explanation or source that you do not agree with you dismiss out of hand (and the dismissal of the Skip Barber info is plain ridiculous), and anyone who disagrees with you is also dismissed.

You drag in discussions that have no relevance (camber and the tranny-trick), to show how everyone always disagrees with you (which I have shown is not true). It strikes me as the position of someone who feels they have backed themselves into a corner and as a result a lot of your explanations are starting to become rather poor quality (which is not what I have come to expect from you).

I’ve always held your opinion in regard (I may not have always agreed), but on this one you are starting to lose my respect in a very big way.

By your own admission your experience of dampers has been limited and you knowledge relatively new, I quote you from Dec last year.

Anyone know real life physics? which is more preferable for fast car in bumpy road, soft damper or hard damper? IMO, hard.

You are still maintaining the same (incorrect) assumption, one which the Skip Barber piece I have quoted (and you seem to dismiss for no valid reason) addresses.


I of course would never condemn someone for holding an opinion, however stating that false information is true is something I have a problem with.

Your knowledge of dampers seems to come from a mixture of Internet articles (often not the best written, unbiased or accurate source) and testing on GT2 and GT4, some of which has been done without the benefit of a true interface and feel.

I have to unfortunately say that you appear to be the only person I know who holds this opinion and in closing this post I have one question to ask.

Given that racetracks allow race-cars to run very firm suspension set-ups. Why would PD provide us with a FC Suspension system (basically a full racing set-up) that allowed a damper range between medium and soft?

This is after all what you are saying, and it (putting aside all the testing and opinion) makes no logical sense at all. Truly soft damper settings have no place on the track, so (from a purely logical standpoint) would it not make more sense that PD would provide a range from medium to firm?

Regards

Scaff

 

[KSaiyu]

Dear Polyphony,

PLEASE use proper, recognised values like Richard Burns Rally has for your next game (GT4 online would be nice).

Thanks

 

[Scaff]

Dear Polyphony,

PLEASE use proper, recognised values like Richard Burns Rally has for your next game (GT4 online would be nice).

Thanks

LOL now that would make life easier.

Scaff

 

[Dave_George]

Ok. I guess I am the only one that think 10 damper is softer, higher camber is slippier in corner, tranny trick is faster, etc. And it is funny that even though I don't have GT4, I am the one that create https://www.gtplanet.net/guides/index.php/Gran_Turismo_4_:_Tuning and contribute 80% of it.

I agree that lower setting hold the road better too, but for me it indicate to me that 10 is too soft. As I say, I think damper setting range from too soft to medium. Your opinion show you think damper range from medium to too stiff.

1st) I would be very hesitant to accept any information in the guides when during this thread you have been given countless amounts of information that doesnt seem correct and has in my opinion been proven incorrect also.

2nd) Please do not tell me what my opinion shows, My opinion is that GT4 damping ranges from soft to stiff, it would make sense for them to have a range that covered most eventualities and this is what I believe is the case.

regards

David

 

[sucahyo]

Try hacking the stabilisers as well, then you will have nothing but springs to support the cars weight, or the opposit; hack the springs to 0, and the stabilisers to 0. Check dampers after that, from 0 to whatever (255?) But do you know for a fact that the hacked values will actually represent that value? If I were you, I´d try to concentrate on the actual in game values instead.

Hacking stabilizer to make it null is impossible, 0 value do not have the effect of 0 stabilizer. it just like the difference between 1 and 2.
hacking the spring to 0 will result in very soft spring.
0 damper compared to 1 is just like damper 1 compared to 2.
About validity, it is much much easier for PD to not limit the game physics engine input to a certain range.
About usefullness, I tune the game better after I know what the effect of hacked value are. The most usefull finding for me is toe hacking. Now, if I want to reduce drift I will use -4 (because -120 make turning easier), etc.

Why would it be banned here at GT4?

I just assume that.

On the subject of higher camber loosing grip in corners, a number of us agreed with you (including me), we simply questioned you’re method of setting the right camber value. You prefer a visual approach, I prefer a testing based approach. I think most people agreed that extreme camber values cause problems, but that what constituted extreme will vary from car to car, track to track and driver to driver.

Thanks . I use visual just as proof, I tune the Falken GT-R entirely from feeling. When I notice that on 4/4 spring, 1.0 front camber feel has less grip than 0.0, I don't check the visual anymore.

In regard to the ‘tranny-trick’ again some people agree with you others don’t, personally I don’t use it, but have seen good write-ups of it working in some cars and not in others. I my second guide I actually include a piece on it because so many people use it or what to know about it.

Ok. But my tranny trick is not exactly the same as that. I always use smallest final drive in my tranny trick, if smallest do not give problem.

Do you own GT4?

Yes, but as I don't have PS2 I play it at my friend's. I use maxdrive and Duck's savegame (thank's Duck , very complete save 👍 ).

Do you play it on a PS2?

For 300mph and DSJ I use PSTwo, for hacked value I use PC (I don't know how to do it in PS2).

All that I write in the guide mostly from summarizing other people's work (including yours). I don't write something that isn't agreed by many people (including mine). Except for the tranny trick part, which I began to write after hearing that DE's Audi R8 has 1st gear speed of 80mph, where mine is 109mph. I write it because it seem nobody notice it exist.

Yes my opinion and many others is that the 1 to 10 range runs from a medium-ish value to firm.

Ok.

I still don’t understand how you believe that a medium setting (1 in your world) would improve you’re road holding and response over bumps compared to a soft setting (10 in your world)?

Matching spring stiffness, stiffer spring with stiffer damper. Stiffer spring make bound and rebound speed increase (frequency increase). Making the wheel will over response when meeting bump, the wheel rebound will already past "zero" point when meeting another bump.
It may also possible that the wheel already starting another bound cycle. After bump the wheel go up, down, and starting to go up again. If another bump happen the wheel will receive bump force and spring force when going up (the wheel position is bellow zero point, so the spring will pull the wheel up). This can make the car jump if both bump force and spring force is high.
Over response when meeting bump is corrected by increasing damper stiffness.

The way a damper works is the same; that doesn’t change. However a bike just has front rear transfer as far as the dampers are concerned. Cars have four corners and left:right and front:rear transfer. The forces placed on the dampers and how they work in relation to each other is different.

Ok.

Yes it can happen with very, very soft damper settings (I don’t recall saying it could not), but are you seriously trying to say that BTCC cars jump when hitting curbs because they run very soft set-ups?

No, I am not sure about that, I am trying to say that in GT4 there is that probability.

Again I did not say you would not experience too soft damping, I said that you could not predict what damping effect you would get!!

We have different opinion, I assume the unpredictability is damper force over time is unpredictable, sometime it medium, some time it soft, and maybe some time it very stiff too.

Have you read this book?

No.

If not how the hell do you know what it does or does not cover on damping?

from your quote only.

It covers damper interaction (and how every force working on a car causes it to react in a given situation) and more in far more detail than any of the internet links you have provided.

Ok.

In addition you have singularly failed to answer the very direct question I asked you in regard to this. Now please either accept that a car that is not in contact with road through dampers being too stiff to react is ‘unstable’ or explain how a car in this condition would be stable.

That is also unstable, I use word unstable incorrectly, that is why I give two option of unstable after that.

Schumacher's crash in todays Australian GP clearly demonstrated this, he ran wide onto the grass and hit a nasty bump, the resulting loss of tyre contact with the surface unsettled the car so much he lost control and hit the barrier. Sounds like a fairly unstable situation to me.

I don't view it as unstable. I assume unstable means you get intermittent control over the grip.

In regard to the term 'unstable' I believe part of the problem here may come from what appears to be a very singular definition of unstable that you appear to have.

Yes.

Its level of detail and accuracy in every subject I have used it in simply is hard to beat, it is bluntly put one of the foremost reference books in motorsport.

Ok, thank's for the explanation .

You can doubt all you like, I’m the one who sat down and did a full back to back comparison of the entire GT series as far as damping when.
I’m sorry but its your ability to read feel that I would place in doubt here, I would also seriously question your ability to compare it to real world feel encountered in a car on a track.

Ok, but I still don't agree that GT1 have the same damper behaviour as GT2 and GT4. In GT1 it will give violent bounce using stiff spring and not in GT2 or GT4.

And I totally disagree with you, the first example is a much better match to what I have felt and seen with higher damper values. However the person to answer this one is Team666 himself.

Ok.

In closing I have to say that your attitude on this one is becoming one of almost blind arrogance. Any explanation or source that you do not agree with you dismiss out of hand (and the dismissal of the Skip Barber info is plain ridiculous), and anyone who disagrees with you is also dismissed.

You drag in discussions that have no relevance (camber and the tranny-trick), to show how everyone always disagrees with you (which I have shown is not true). It strikes me as the position of someone who feels they have backed themselves into a corner and as a result a lot of your explanations are starting to become rather poor quality (which is not what I have come to expect from you).

I’ve always held your opinion in regard (I may not have always agreed), but on this one you are starting to lose my respect in a very big way.

By your own admission your experience of dampers has been limited and you knowledge relatively new, I quote you from Dec last year.

Ok. But you must realize that I seldom receive an "I agree with you" answer in here.
About camber, I don't know that you agree too. I don't see many people using low camber when they use stiffer spring (I see some setting which do this though). My experience when trying to tune Falken GT-R and Ford Mustang GT show that a 2.0 front camber has less grip than 0.0 (by feeling only, all N1 tire), as I rarely see people using front camber less than 1.0 I assume that I am the only one that think camber need to be small when the spring rate is stiff.
About tranny trick you should know that my tranny trick is different from common tranny trick. I never notice anyone else using purposefully use smallest final drive or tranny trick variation. I am apologize that I mention this when I never create a thread that specifically discuss this (in GT4). I think what make my 300mph cars have higher than average rangking is because many people don't use this, I can't think any other reason why a 300mph newbie like me can beat the senior.

You are still maintaining the same (incorrect) assumption, one which the Skip Barber piece I have quoted (and you seem to dismiss for no valid reason).

Because I also assume that the damper in GT4 do not have such too stiff damper like your quote mentioned. In other word, I assume that although (borrowing from skip barber quote) "but remember that stiff settings slow down the suspension movement by having higher resistance to motion" is possible, "it may not be able to react fast enough to keep the tires in contact with the road" will never happen in GT4.

And if I use Skip Barber quote then
"A stiffer bump setting slows down the motion on its corner and speeds up the load transfer. A softer bump setting does the opposite - it allows the suspension to move faster and spreads the changes in loading out over a longer period of time. The same is true of rebound. Stiff re-bound settings will force the suspension system to move more slowly when loads are removed from its corner of the car, but the unloading of the contact patch will be more abrupt. Softer rebound settings allow the suspension to move more quickly and the unloading of the contact patch happens more gradually"
explain exactly what I feel when using damper 10/1 1/10 vs 10/10 10/10 on my 300mph cars. Nodding on nose rise is slower than nose drop.
When the nose rise the affected part is front rebound and rear bound, setting this value to stiff (1 in my case) make rising speed slower.
When the nose drop the affected part is front bound and rear rebound, setting this value to soft (10 in my case) make dropping speed faster.

I hope it's clear that I am not dismissing your Barber Skip quote.

I of course would never condemn someone for holding an opinion, however stating that false information is true is something I have a problem with.

No, I still believe that damper 10 is softer, and I use this on all my tuning, even on 300mph and DSJ tuning. I always start from 10/10 10/10 damper thinking that damper should be soft to allow more tire reaction to the road, if this give problem I lower it. If the car reaction feel slow I will use 1 damper. When I have problem with my falken countersteer (snappy) I use front 1 damper. When the 300mph car turning is very sensitive, I use front 1 damper and 7 stabilizer. On my recent GT2 Elise at autumn ring, feeling that 10/10 10/10 make the car twitchy, I use 1/10 1/10.

Your knowledge of dampers seems to come from a mixture of Internet articles (often not the best written, unbiased or accurate source) and testing on GT2 and GT4, some of which has been done without the benefit of a true interface and feel.

The internet part is true, but I don't know what you mean by true interface and feel. If you are talking about analog control, it's true that I don't have wheel.

Given that racetracks allow race-cars to run very firm suspension set-ups. Why would PD provide us with a FC Suspension system (basically a full racing set-up) that allowed a damper range between medium and soft?

Because stiff damper code is buggy or inaccurate. The example is when we use 10 damper in GT1, the car speed will be slowed down on every bump without any loose of control, the car jitter around but still drivable. This is I think is unrealistic.

Truly soft damper settings have no place on the track, so (from a purely logical standpoint) would it not make more sense that PD would provide a range from medium to firm?

It make sense. Simulating road car behaviour which has soft damper can be done by changing internal damper multiplier or using another internal damper data when stock.

1st) I would be very hesitant to accept any information in the guides when during this thread you have been given countless amounts of information that doesnt seem correct and has in my opinion been proven incorrect also.

No need to, most information is not my work, I just write it after seeing it abandoned.

2nd) Please do not tell me what my opinion shows, My opinion is that GT4 damping ranges from soft to stiff, it would make sense for them to have a range that covered most eventualities and this is what I believe is the case.

Ok.

 

[Mt. Lynx]

Hacking stabilizer to make it null is impossible, 0 value do not have the effect of 0 stabilizer. it just like the difference between 1 and 2.
hacking the spring to 0 will result in very soft spring.
0 damper compared to 1 is just like damper 1 compared to 2.
About validity, it is much much easier for PD to not limit the game physics engine input to a certain range.
About usefullness, I tune the game better after I know what the effect of hacked value are. The most usefull finding for me is toe hacking. Now, if I want to reduce drift I will use -4 (because -120 make turning easier), etc.

Ok.

Matching spring stiffness, stiffer spring with stiffer damper. Stiffer spring make bound and rebound speed increase (frequency increase). Making the wheel will over response when meeting bump, the wheel rebound will already past "zero" point when meeting another bump. It may also possible that the wheel already starting another bound, the wheel go up, down, and start to go up again. If this happen the wheel will receive bump force and spring force when going up (the wheel position is bellow zero point). This can make the car jump if both bump force and spring force is high.
Over response when meeting bump is corrected by increasing damper stiffness.

And there you go. Yes, stiff springs require stiffer damping, but neither stiff springs nor dampers are the way to go over bumpy surfaces. And the scenario you describe is somewhat flawed. A stiff spring does not actually increase frequency of the dampers, it´s rather the opposite. The dampers are there to slow the springs frequencies, to control them. And stiff springs need stiffer dampers. But for a bumpy track, smoothness is vital if you want to keep contact with the roadsurface, so springs, and dampers, has to be set at a lower value to optimize grip. This is really easy to understand. What follows the countour of a surface best, something soft, like foamrubber, or a lump of steel?

Because stiff damper code is buggy or inaccurate. The example is when we use 10 damper in GT1, the car speed will be slowed down on every bump without any loose of control, just like hitting some thin wall. This is I think is unrealistic.

But this is GT4, and it has totally different physicsengine, so they are not comparable, really.

 

[sucahyo]

Yes, stiff springs require stiffer damping, but neither stiff springs nor dampers are the way to go over bumpy surfaces. And the scenario you describe is somewhat flawed. A stiff spring does not actually increase frequency of the dampers, it´s rather the opposite. The dampers are there to slow the springs frequencies, to control them.

I don't know what you mean about spring increase frequency of the damper. Stiffer spring has higher cycle frequency, I get it from this http://www.smithees-racetech.com.au/performancefactors.html. It make wheel waving faster.
If the bump is sound wave, the best road countour following spring is the one with the same frequency, the damper will try mute or reducing the amplitude of the wave caused by bump.
Stiffer spring have higher frequency, softer spring have lower frequency, if the frequency don't match, it will give problem.
Stiffer damper will reduce the amplitude more, softer damper will reduce the ampiltude less, if the damper is too high or too low it will give problem.

And stiff springs need stiffer dampers. But for a bumpy track, smoothness is vital if you want to keep contact with the roadsurface, so springs, and dampers, has to be set at a lower value to optimize grip. This is really easy to understand. What follows the countour of a surface best, something soft, like foamrubber, or a lump of steel?

IMO, spring stiffness that has the same cycle frequency as bump frequency. So a 1.6 ton supra RZ would need 50lb/in spring when the bump frequency is 96cpm. So both the foam rubber and lump of steel don't follow the road contour properly, although foam rubber has better chance.

But this is GT4, and it has totally different physics engine, so they are not comparable, really.

I have different opinion, I'll say the main calculator still the same, even though it's been finely tuned to make it better. KY say that GT1-3 is first generation, and GT4-GT5 is second, but I don't think the engine change very much.

 

[Mt. Lynx]

I don't know what you mean about spring increase frequency of the damper. Stiffer spring has higher cycle frequency, I get it from this http://www.smithees-racetech.com.au/performancefactors.html. It make wheel waving faster.

I did not say spring increase the frequency of the damper, I said damper reduce spring frequency, or rather control it. That´s why you have dampers at all.

If the bump is sound wave, the best road countour following spring is the one with the same frequency, the damper will try mute or reducing the amplitude of the wave caused by bump.
Stiffer spring have higher frequency, softer spring have lower frequency, if the frequency don't match, it will give problem.
Stiffer damper will reduce the amplitude more, softer damper will reduce the ampiltude less, if the damper is too high or too low it will give problem.

Yes, that´s why tuning is always a compromise, and never spot on. Since a track always will have different kinds of turns, bumps, straights and surfaces everything you do setupwise will be a compromise to get the car to be as neutral as possible over the length of a track.

IMO, spring stiffness that has the same cycle frequency as bump frequency. So a 1.6 ton supra RZ would need 50lb/in spring when the bump frequency is 96cpm. So both the foam rubber and lump of steel don't follow the road contour properly, although foam rubber has better chance.

See above. A bumpy track requires a softer setup than a smooth one, and that is just plain logic.
And to get back to GT4, I can advise you to run a racecar, preferably something like the Audi R8, at Nürburgring. Set everything very high value, run 3 laps and then set everything to low value and run 3 laps. Wich setup held the road best? It will be the lower value one, I promise you. And that will also tell you that low values=soft and high values=hard, since such a bumpy road will need a softer setup to even stay on track.

I have different opinion, I'll say the main calculator still the same, even though it's been finely tuned to make it better. KY say that GT1-3 is first generation, and GT4-GT5 is second, but I don't think the engine change very much.

I think the feel for the cars and the overall physics changed a lot between 3 and 4.

 

[Scaff]

Matching spring stiffness, stiffer spring with stiffer damper. Stiffer spring make bound and rebound speed increase (frequency increase). Making the wheel will over response when meeting bump, the wheel rebound will already past "zero" point when meeting another bump.
It may also possible that the wheel already starting another bound cycle. After bump the wheel go up, down, and starting to go up again. If another bump happen the wheel will receive bump force and spring force when going up (the wheel position is bellow zero point, so the spring will pull the wheel up). This can make the car jump if both bump force and spring force is high.
Over response when meeting bump is corrected by increasing damper stiffness.

Most of the above has already been well covered by Team666, so I'm not going to go over the same ground again (edited to add that this is now a lie - bloody big post warning).


The Spring Bit
The link you provided in reply shows what (I hope) most people know and thats stiffer springs have a higher natural frequency in cycles per minute. However what it also shows (and this may be new to some) is that this is dependent on the cars weight.

Take a two cars both fitted with 100lb/in springs. Car A weighs 400lb per wheel (sprung weight) and car B weighs 800lbs per wheel (sprung weight). The CPM frequency for each car is approx. Car A = 80cpm and Car B = 66cpm.

In other words despite both cars having the same spring rate, the springs in Car A will be stiffer sprung than Car B. Its why spring rates can't be dirrectly compaired car to car, the weight of the car is critical.

Now that interesting bit aside, the linked article does not discuss in any way how the spring frequency effects the control of a car over bumps. The Smithees tech pages are very good, but as I mentioned previously they mainly focus on handling balance and stability.


Gettting Silly with Dampers
The scenario you are decribing in the second part of your post above is for a car that is terminally underdamped for its spring rate. The dampers are not capable of controlling the spring frequency. For this to occur the car would have to be more softly damped than any car I have ever come across or encountering bumps far greater than any I have found on a race track, and doing so at high speed.

In other words its a theoreticaly possiable (but very unlikely in the real world) situation. Now I would agree that stiffening the dampers would certainly be required here.

Now lets look at the other end of the scale, a car that was totally overdamped (as firm as imaginable), so that the frequency of the spring rate is overwelmed by the damper. In this situation when the car encounters a bump (or series of bumps) the damper will not allow the car to suspension to react to the impact at all, sending the force directly through the suspension to the car. Almost the same as if we had fitted the car with steel bars instead of suspension, the car would be launched upwards at the point of impact with the bump.

These are two very extreme ends of a scale. One with dampers so soft that they don't control the spring frequency and the other so hard that it does not allow the spring to be effective at all.

While they serve to illustrate a point, they are not realistic scenarios.

Now I think that its beyond any doubt that if you were unforunate enough to be in a car set-up as above when it hit a bump you would feel very different things.

The first car would be very, very soft and wallowy in feel, as you hit a bump it would occalate on the spring in an uncontrolled manner, if this was sufficent to cause a wheel to leave the ground you may not even feel it.

The second car by compariosn would be teeth shattering, every slight imperfection in the road surface would only have the tyres sidewall to absorb it, the rest would be passed through to the occupants. Hit even a small bump at speed and the car is going to lose conatct with the road,and as that corner returned to earth the force would have nothing to absorb it. Very harsh and very painful.

Now real-world settings lie between these two points, as do GT4s, but they do give us a couple of useful pointers.

The first is that from all we have looked at above, first the effect of a spring rate is dependent on the weight of the car. Second that dampers must be matched to the spring rate (to a degree) to ensure that gross over or underdamping doesn't occur.

Finally that under-damping is going to feel soft (no big surprise here) and that over-damping is going to feel harsh (again no major surprise here).

This is confirmed by a guide I have (hard copy only I'm afraid) on damper tuning written by Ohlins (major suspension component manufacturer) which uses the following terms to describe under (soft) and over (firm) damping.

Too Soft Damping = bouncy, soft and a tendancy to bottom out easily in long dips.

Too Firm Damping = hard, bumpy - especially over a series of bumps, harsh, and has hard resilience.


What all the above has to do with GT4 and this thread
Quite simply what I believe you are missing out on most and the single reason for your belief that high values are soft is that you are still (and again) focusing mainly on visual evidence. This is not strange as you mainly use a PC emulator and keyboard to play GT2 and have to go around a friends to play GT4 (and I believe using a DS2 rather than a wheel). It does however (as you have said yourself) cause problems because of a lack of dedicated wheel cam.

Sit down and run a number of tests (the Caterham ones from ages ago are good as the light weight of the car highlights the weight effect on spring rates from above). Run the car around Deep Forest and drive over the curbs, etc. The feel of the car as it passes over the changes in track is hard and harsh with high values, but is greatly smoothed out with lower damper values.

The will never go entirely due to the cars weight in relation to the spring rates. So then change to something nice and heavy like the Dodge and with a low damper value you can hardly feel the rumble strips.

Finally load up the Integra Type-R touring car and carry out the curb tests, with a high damper value as you hit the curb and that side of the car launches you can feel the short, sharp hard force.

You can feel this with a DS2, but it is far, far better with a good force feedback wheel.

I honestly think that this lack of feel is causing a lot of the problems, I can see why by using mainly visual feedback you have mistaken the lose of control on the high (hard) damper settings for soft bouncing.


I'm sorry to all for the very, very long post and I hope that it does make sense.

Regards

Scaff

 

[sucahyo]

Ok, I think I will try to test the feeling like you all advises on my next chance.
Lets hope that PD do not use soft for high value because they think it's closer to real life feeling than their stiff damper simulation code.

And to get back to GT4, I can advise you to run a racecar, preferably something like the Audi R8, at Nürburgring. Set everything very high value, run 3 laps and then set everything to low value and run 3 laps. Wich setup held the road best? It will be the lower value one, I promise you. And that will also tell you that low values=soft and high values=hard, since such a bumpy road will need a softer setup to even stay on track.

Yes, that happen, but in my case comparing stiff vs soft mean:
high spring rate (stiff) and low damper (stiff) - VS - low spring rate (soft) and high damper (soft)

Pairing stiff spring with soft damper of course is more undrivable than pairing soft spring with stiff damper. I read somewhere that M5 is tuned using soft spring rate and stiff damper, and M5 is tuned in Nürburgring.

I think the feel for the cars and the overall physics changed a lot between 3 and 4.

Ok. But I don't know if it come out from code rewrite from scratch (would need a long time).
BTW I notice some funny workaround, in GT2 car is faster when using low front and high rear ride height (1000m). And in GT4 R8 and R92CP car is faster (although less pronounce) when using high front and low ride height (300mph), they reversed it .

 

[Mt. Lynx]

Ok, I think I will try to test the feeling like you all advises on my next chance.
Lets hope that PD do not use soft for high value because they think it's closer to real life feeling than their stiff damper simulation code.

Yes, that happen, but in my case comparing stiff vs soft mean:
high spring rate (stiff) and low damper (stiff) - VS - low spring rate (soft) and high damper (soft)

Pairing stiff spring with soft damper of course is more undrivable than pairing soft spring with stiff damper. I read somewhere that M5 is tuned using soft spring rate and stiff damper, and M5 is tuned in Nürburgring.

OK, but that still don´t mean much, you´ll have to test it like this: high value spring and high value damper, low value spring and high value damper, low value spring and low value damper, high value spring and low value damper. The overall best one will be low/low!

Ok. But I don't know if it come out from code rewrite from scratch (would need a long time).
BTW I notice some funny workaround, in GT2 car is faster when using low front and high rear ride height (1000m). And in GT4 R8 and R92CP car is faster (although less pronounce) when using high front and low ride height (300mph), they reversed it .

It did take a long time! IIRC GT4 was in development for 4 years.

yeah, the high front thingy is somewhat of a glitch, or a flaw, if you like. Has to do with GT4:s inability to recreate airflow and downforce in a proper manor.

 

[sucahyo]

The overall best one will be low/low!

Yes, the best one is low spring rate and low damper. As in my case explanation:
- there is no bump frequency that is high enough to make low (soft) spring fail to follow the road contour.
- the spring is not restricted much even with lowest (stiffest) damper

This is what I feel on GT2 Lotus Motorsport Elise on Deep Forest (I don't think I'll be able to test it on GT4 soon).
ride height max, stabilizer min, zero camber and toe.
high spring rate = 12/12, low spring rate = 4/4
high damper = all 10, low damper = all 1

high/high, very unstable, even keeping the car on the straight road is very difficult. The car bouncing around even at low speed. hard and brutal.
low/high, more stable, but the car tend to turn, and counter steer make it drift. It make me drifting car drift left to right on straight because the snap steering. soft and loose.
low/low, very stable, the most easiest to drive. soft and tight
high/low, stable, better than low/high combination. Although it can be little bouncy on corner. hard and tight

loose = steering feels unconnected
tight = steering feels connected

It did take a long time! IIRC GT4 was in development for 4 years.

I see.

yeah, the high front thingy is somewhat of a glitch, or a flaw, if you like. Has to do with GT4:s inability to recreate airflow and downforce in a proper manor.

I hope it didn't create ride height sweet spot or optimum ride height elevation . I don't think I have time to test wether the best ride height is low/low, high/low or mid/low .

 

[Mt. Lynx]

Yes, the best one is low spring rate and low damper. As in my case explanation:
- there is no bump frequency that is high enough to make low (soft) spring fail to follow the road contour.
- the spring is not restricted much even with lowest (stiffest) damper

This is what I feel on GT2 Lotus Motorsport Elise on Deep Forest (I don't think I'll be able to test it on GT4 soon).
ride height max, stabilizer min, zero camber and toe.
high spring rate = 12/12, low spring rate = 4/4
high damper = all 10, low damper = all 1

high/high, very unstable, even keeping the car on the straight road is very difficult. The car bouncing around even at low speed. hard and brutal.
low/high, more stable, but the car tend to turn, and counter steer make it drift. It make me drifting car drift left to right on straight because the snap steering. soft and loose.
low/low, very stable, the most easiest to drive. soft and tight
high/low, stable, better than low/high combination. Although it can be little bouncy on corner. hard and tight

loose = steering feels unconnected
tight = steering feels connected

Your findings tell me that low/low is soft/soft, because of the high/low, low/high behaviour. The bouncy feel with high/low comes from hard springs that is not controlled by the dampers properly - wheelhop if you will. The springs have a more direct effect on the car than dampers, that is why the feel of springs is greater than the feel of the dampers. Damping is a secundary effect, like I´ve said earlier, and controls the springs.

I hope it didn't create ride height sweet spot or optimum ride height elevation . I don't think I have time to test wether the best ride height is low/low, high/low or mid/low .

Bleh, that would suck! I don´t think they did, since a too low car is not to recommend! And I think your weighttransfer "science" should be very good to find this out, or at least to find out if the car should be low/high, low/low, high/high or even high/low.

 

[sucahyo]

The bouncy feel with high/low comes from hard springs that is not controlled by the dampers properly - wheelhop if you will. The springs have a more direct effect on the car than dampers, that is why the feel of springs is greater than the feel of the dampers. Damping is a secundary effect, like I´ve said earlier, and controls the springs.

Yes, hard damper can cause that too. But how about the unconnected and connected feel? IMO, It's the opposite of what damper suppose to feel. Shouldn't hard damper feel more connected than soft damper?

or at least to find out if the car should be low/high, low/low, high/high or even high/low.

I don't know, it seem only affect high speed only, so it may have something to do with air resistance. I hope ride height combination that has the least air resistance is the same for every car. So if we use highest/lowest we get best aerodynamic for 300mph . If it don't we have to experiment different ride height combination for every car .
Maybe we should create a jet fighter figure. So, if the nose is tall, we lower the front, if the the nose is low, we raise the front .

 

[Mt. Lynx]

Yes, hard damper can cause that too. But how about the unconnected and connected feel? IMO, It's the opposite of what damper suppose to feel. Shouldn't hard damper feel more connected than soft damper?

Yes and no! That depends on the springs! If both springs and damper are hard, you will get, as you put it, a connencted/unconnected feel. If both are soft, you will get a smoother feel, and more surfacecontact, but this is not always the best way to set up suspension, especially not on a racecar. Racers seem to sacrifice a smooth ride for a faster cornering car, wich is logical if you want to get a fast time around a track.
If springs are soft and dampers hard (and stabilisers soft), you can suffer from extensive chassis movement, IE the body of the car "floats" on the suspension, and this may cause loss of grip while turning. The weighttransfer will go more straight, instead of moving slightly downwards.

Simply put, a soft damper can move in longer frequencies and do it faster, than a hard damper. Think of it terms of pressure. The higher the pressure, the harder the damper, and more pressure means more force is needed to get the same movement as in a damper with less pressure.

I don't know, it seem only affect high speed only, so it may have something to do with air resistance. I hope ride height combination that has the least air resistance is the same for every car. So if we use highest/lowest we get best aerodynamic for 300mph . If it don't we have to experiment different ride height combination for every car .
Maybe we should create a jet fighter figure. So, if the nose is tall, we lower the front, if the the nose is low, we raise the front .

Hmm, I think the 300 mph runs are overriding the physics somehow. And especially since more downforce means more speed! That is just plain stupid! PD has to check their build on aerodynamics...

As for rideheight combinations, the same rule apply as to everything else; depends on track, car and driver! A bumpy track=higher rideheight and a smooth track the opposite! And some cars, mainly american FR cars, seem to benefit in handling by a low/high setting. Or, well, have the rear 10 to 50 notches (1 to 5 centimetres) higher than the front.

 

[Scaff]

OK I’ve been running some more tests on the Caterham at Deep Forest and have come up with another very good example.

Take a the Caterham (in this case mine was fully tuned – running around 228bhp) and set it as follows

Spring rate – minimum front and rear (you should be aware that even settings this low are going to still be quite stiff given the weight of the car)
Ride Height – Maximum front and rear
Anti-roll bars – Front 1 and Rear 3
Ballast – Weight 200 Location –50

The above is set up to ensure maximum weight transfer possible to the front of the car, the front ARB is set to its minimum so it effects the test as little as possible.

Now with the minimum spring rate the car should on soft damper settings allow the car to track the road well over bumps, rumble-strips should feel quite smooth (you’re always going to feel something – it is a Caterham after all). We should also see a good degree of movement from the suspension wishbones.

The hard damper settings should over-damp the soft spring to such a degree that the car will act almost as if it is sprung much more stiffly than it is. As such I would expect to see the car skipping over bumps that the softer set-up coped with, rumble strips should feel (and sound) harsh with the characteristic hard brrrrappp sound (as opposed to the much softer sound associated with softer set-ups). This should also reduce the amount of visible movement in the suspension wishbones.

Now while GT4 does not offer the very handy ‘wheel-cam’ that GT2 does, we can use the exposed front suspension on the Caterham to our advantage here. As GT4 does let us go into a fixed rear view, simply make sure the replay is in follow-cam (behind the car) and then press L1. You should now have a fixed view of the front of the car, with a good view of the front suspension.

Dampers 1/1 front and rear
First my impressions from the drive itself, the car feels as if it tracks the bumps well and while I can notice the rumble-strips the suspension seems to be coping well with them and the sound of the strips is soft. It is possible to unsettle the car, but you need to hit a large curb at speed.

On the replay the extra weight transfer on the front of the car is very clear to see and the front suspension wishbone movement is clear.


Dampers 10/10 front and rear
Driving the car it now feels far stiffer than before with far more difficulty laying down traction. Bumps that previously were of minor importance are now an issue and riding any of the curbs launches the car in the air. Rumble strips are very definite in feel and the brrrrappp sound is clearly heard and sounds hard and harsh.

On replay the front suspension is now visibly moving less and the movement that is present is clearly slower than before. Additionally when hitting a curb and the seeing the car launch in the air, its clear to see than this is not the result of oscillation from under-damping, the car is sent up as soon as it hits the curb. The suspension having no chance to react at all.

Conclusion
In my mind carrying out the above tests (and I have repeated them over and over) has re-enforced my belief that lower values are softer and higher values are firmer with damper settings in GT4.

All the characteristics displayed in the above tests support this and I have repeated the tests a number of times and the results are consistent.

Lower values allow the springs and dampers to react to the bumps and surface changes as well as providing visibly quick suspension movement and a softer feel.

Higher values by contrast both slow down and reduce the movement of the suspension, reducing its ability to react to bumps while providing a very hard and stiff feel to the car.

Now the above is not meant as an indication of which is better for a set driver or car, as one thing I have always maintained is that a car should be set-up for a driver and their style. Remember even with the best simulations in the real world to set up a racecar, the driver will still end up having it tweaked to what ‘feels’ right for them. This happens time and time again in top-level motorsport, just listen to the drivers after practice and qualifying during an F1 race weekend.

Regards

Scaff

 

[sucahyo]

Thanks for the test Scaff . The result is different from GT2 elise, but the lightest car in GT2 (Midget) is still above 1000 lbs though. Do you think the result will stay the same for heavier car? I wish I can play GT4 soon .

Yes and no!
Simply put, a soft damper can move in longer frequencies and do it faster, than a hard damper. Think of it terms of pressure. The higher the pressure, the harder the damper, and more pressure means more force is needed to get the same movement as in a damper with less pressure.

If both spring is soft, hard damper should be prevent body roll more than soft damper right? And less body roll equal to more connected feel right?

A bumpy track=higher rideheight and a smooth track the opposite! And some cars, mainly american FR cars, seem to benefit in handling by a low/high setting. Or, well, have the rear 10 to 50 notches (1 to 5 centimetres) higher than the front.

Yes, I agree. Although in GT4 I prefer huge rear camber to balance the car, easier to measure for drifting . And If I start to do race tuning I think I will use high front and low rear for all cars, if all my 300mph cars require it too .

 

[Mt. Lynx]

Thanks for the test Scaff . The result is different from GT2 elise, but the lightest car in GT2 (Midget) is still above 1000 lbs though. Do you think the result will stay the same for heavier car? I wish I can play GT4 soon .

If both spring is soft, hard damper should be prevent body roll more than soft damper right? And less body roll equal to more connected feel right?

Not necessarily. A too hard damper would only feel erratic, and cause vibrations through the body of the car. I would not recommend to reduce bodyroll with harder dampers, since springs have greater effect and damping only is sort of the "co-worker" to the springs.

Yes, I agree. Although in GT4 I prefer huge rear camber to balance the car, easier to measure for drifting . And If I start to do race tuning I think I will use high front and low rear for all cars, if all my 300mph cars require it too .

But I do think that braking/turning with a high/low setting will get kind of troublesome

 

[sucahyo]

Not necessarily. A too hard damper would only feel erratic, and cause vibrations through the body of the car. I would not recommend to reduce bodyroll with harder dampers, since springs have greater effect and damping only is sort of the "co-worker" to the springs.

Ok.

But I do think that braking/turning with a high/low setting will get kind of troublesome

Yes, more understeer, but camber many times more powerfull than ride height . I use low/high ride height all the time in GT2 .

 

[Mt. Lynx]

Ok.

Yes, more understeer, but camber many times more powerfull than ride height . I use low/high ride height all the time in GT2 .

I did that in GT3 also, and I used more camber in GT3 too, wich tells me that the tuning is more sensitive in GT4. The different settings have greater effect on the cars in GT4, than in previous games (at least GT3).
I have recently started a new save for GT3, and I`m telling you, the leap between GT3 and 4 is pretty vast! In GT4, I can get a feel for the cars weight, it´s transfer and the limit of the grip both front and rear. That was much, much harder in GT3! Weighttransfer contra grip is pretty much abscent in GT3, allthough a feel for the cars grip is present. And GT3 is much more forgiving at the limit too. It is easier too screw up in GT4!
Overall, the settings in GT4 are much more sensitive!

 

[Scaff]

Thanks for the test Scaff . The result is different from GT2 elise, but the lightest car in GT2 (Midget) is still above 1000 lbs though. Do you think the result will stay the same for heavier car? I wish I can play GT4 soon .

I've run these tests on a number of different cars now, and while it is harder to see the visual aspect on any car with enclosed wheels the reverse view does help. Certain the 'speed' at which the suspension reacts is clear to see, which the higher damper values slowing the reaction down (a clear indicator that higher = firmer).

Watching the car when it losses contact with the road and seeing if it happend immediatly is much easier with this view, I ran the Intergra Type-R Touring Car test again and its clear to see that its the result of a hard set-up.

More straightforward to check are the feel and sound of the car, again higher damper values react with the same characteristics as the Caterham.

BTW There is no reason to think that this would or should change for different cars, if the high values are firm (and they are) then that will be the case for tuning on all cars.

I'm kicking myself for not thinking of this particular test earlier (and remembering this view) as it does make it clear to see.

If both spring is soft, hard damper should be prevent body roll more than soft damper right? And less body roll equal to more connected feel right?

As Team666 said that is true but its not an ideal way around it.

Take the test on the Caterham above, the hard damper settings are clearly restricting the ability of the springs to work and therefore body roll is reduced.

However this will have no effect at all on the amount of weight that is transfered, only how it is distributed at the end of the car it is transfered to or from (see Greyout's stickied guide on springs and weight transfer above or in Pt1 of my tuning guide). As over-damping springs will limit the work they can do and to a certain degree make they act as if they were actually a higher spring rate (stiffer).

Additionally the hard damper settings in the Caterham test simply did not suit the bumpy nature of the Deep Forest Track at all, the car felt unstable and disconected from the track as the suspensions inability to cope with the bumps made the tyres lose contact with the track surface. You can't get much more of a disconected feeling than that.

Team666 has already touched on this, spring rate should be tuned for the car weight and the nature of the track surface. The spring rate relationship, front to rear, can be used to balance the car by controling how the weight that is transfered is distributed between the tyres at a given end.

Dampers can be used to tweak this, but it should not be anymore than a tweak. The strengths dampers give you is the ability to control how fast a car reacts to weight transfer and how it responds to compression and expansion over bumps and surface changes.

They can also be used to tweak the handling balance of the car to assist in controling under and over steer.

tuning is more sensitive in GT4. The different settings have greater effect on the cars in GT4, than in previous games (at least GT3).

Overall, the settings in GT4 are much more sensitive!

Would totally agree with both of those points, GT3 you could get away with fitting FC suspension to a car, not bother setting it up and still win races with ease.

With GT4 very few cars will let you get away with that, you have to tune the cars with FC fitted to get the most out of them, and some are just plain nasty on the default FC settings.

I find that GT4 forces you far more to think about set-ups for each and every track, in no way could a set-up for Grand Valley be considered ideal for the 'ring.

It adds so much more to GT4 in my opinion.

Regards

Scaff

 

[sucahyo]

Overall, the settings in GT4 are much more sensitive!

Yes I agree, recently I try to make my GT2 Mustang behave the same way my GT4 drift Mustang do. I failed, it seem that the tire stick more in GT2. After searching around I finally found the GT2 tire traction code for slip threshold, longitudinal grip and lateral grip (my assumption). After I play around with this I can finally make my GT2 mustang drifting the same way (by halving slip threshold and longitudinal grip). The tuning that I use is exactly the same except for camber, 6.0/0.0 in GT2, 0.0/4.5 in GT4 . So GT2 has mighty oversteer engine and GT4 has mighty understeer engine, GT3 should be somewhere in the middle .

I've run these tests on a number of different cars now, and while it is harder to see the visual aspect on any car with enclosed wheels the reverse view does help. Certain the 'speed' at which the suspension reacts is clear to see, which the higher damper values slowing the reaction down (a clear indicator that higher = firmer).

Thanks . Ok, so that means damper 10 is hard, it's clear that GT2 and GT4 behave differently now.

However this will have no effect at all on the amount of weight that is transfered, only how it is distributed at the end of the car it is transfered to or from (see Greyout's stickied guide on springs and weight transfer above or in Pt1 of my tuning guide). As over-damping springs will limit the work they can do and to a certain degree make they act as if they were actually a higher spring rate (stiffer).

Ok. BTW, do load transfer has the same meaning as weight transfer?

Team666 has already touched on this, spring rate should be tuned for the car weight and the nature of the track surface. The spring rate relationship, front to rear, can be used to balance the car by controling how the weight that is transfered is distributed between the tyres at a given end.

Agree, tuning damper should be done after spring rate tuning.

I find that GT4 forces you far more to think about set-ups for each and every track, in no way could a set-up for Grand Valley be considered ideal for the 'ring. It adds so much more to GT4 in my opinion.

Yes, I experience that changing slip threshold in GT2 really change how the car handle in relation with weight transfer. Not to mention a more pronounce understeer.

BTW, do you know how the relation between lateral grip and longitudinal grip supposed to be for real life normal tire? lateral grip = 2 X longitudinal grip?