Observations on suspension settings

[Merquise]

I have a question: does this 'bug' occur in both online and offline?
Because I often make offline setups, then go online and seriously those cars are virtually impossible to drive.

 

[Dr_Watson]

The differences between "offline" and "online" physics is 90% tire wear 10% lag. The setups should function the same both places.

 

[No_OBsT33R]

Guys, just to be absolutely clear as this thread seems to have taken a tangent towards the aerodynamic effects...

The front high/rear low setting wasn't really about delivering a higher top speed... it's first and foremost a setting to cure/kill understeer. The slight top speed gain is a nice side effect, but the understeer cure is far more important!

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I'm not going to call out individuals, but there are people posting in here who really don't know what they are talking about... anyone who thinks raising the front ride height is simply creating harder/softer spring rate, or that this is therefore allowing more weight transfer etc, just don't understand the fundamentals of car suspension in the real world.

If you don't know what you're talking about it's always better to shut up or ask a question than make a stupid statement!

They are not reversed they are fine, the issue is the lack of under body aero effects.

People are relying on a cheap trick to get faster. If you properly adjust the suspension when tuning it's not an issue, cars handle just fine.

The issue is people getting those few MPH faster with the front jacked up & no under car aero effects to slow them down more than the new top angle may benefit speed. Basically they get benefits of the settings without much draw backs.

 

[TT3AZ]

The stiff front extension should cancel out the soft rear compression.

                           .
       -----  -+---+-     / \
       , - `   |   |       |
       , - `   |   |       |
       , - `   |   |    
       , - `   '==='    Rebound
       , - `    | |        
       , - `    | |        |
       , - `    | |        |
       -----  --+-+--     \ /
                           '
       -----  -+---+-    -----
       , - `   |   |       |
       , - `   |   |       
       , - `   '==='    Neutral
       , - `    | |        
       , - `    | |        |
       -----  --+-+--    -----
                           |
       -----  -+---+-     \ /
       , - `   |   |       '
       , - `   '==='     Bound 
       , - `    | |        . 
       -----  --+-+--     / \
                           |

You've got a spring and a damper which absorbs energy from the spring's bound and rebound. The softer the compression of the damper the more vertical travel the spring will be allowed, and the more energy will be absorbed. Like punching a board vs punching a pillow. the board *hurts* more because newtons law is giving you the equal and opposite business. However the pillow has some *give* as it decelerates your punch slower using more travel, saving your hand from getting the full force. A stiff compression value (10) on the damper would create a board, preventing the spring from compressing. While a soft (1) damper would be the pillow, bleeding off energy while the sprung mass decelerates slower using more travel.

Once the spring has been compressed it wants to rebound back toward it's neutral position. The stiffness of the damper extension determines how difficult it is for the spring to do this and how much energy is bled off in the process. The stiffer the extension the harder it is for the spring to rebound.

So when you leave the line and weight tries to transfer rearward the rear springs and dampers will compress. This means you're right that soft springs and soft damper compression will allow the most weight to transfer to the rear axle (combined with a stiff extension value so the spring doesn't just rebound the weight back forward).
However in the front the opposite is happening. The weight is leaving the axle and so you want a soft extension to allow the most spring to stretch while the front end lifts.

So drag shock damping is more like 10/1 front, 1/10 rear (compression/extension).

Okay man, thank you, but how come I got similar traction and weight transfer while having front extension 10, and rear compression 10? Look at my other examples, something doesnt work out right. But I will try this things out, thanks.

Edit: I tested your settings, the car launched good, but its hard to tell it i were any differance from running front 5/10, rear 5/5 (compression/extension). One this is intresting though, the car spinns a little bit less with the ride height as low as possible for the front, and as high as possible for the rear. The question is if the ride height settings could be reversed, because if my car would be slammed to the ground at the rear (-25), then I wouldnt get that "bouncy" effect and weight transferment either.

 

[Stotty]

They are not reversed they are fine, the issue is the lack of under body aero effects.

People are relying on a cheap trick to get faster. If you properly adjust the suspension when tuning it's not an issue, cars handle just fine.

The issue is people getting those few MPH faster with the front jacked up & no under car aero effects to slow them down more than the new top angle may benefit speed. Basically they get benefits of the settings without much draw backs.

Sorry, but you're wrong.

The top speed thing is irrelevent. It's the effect the ride height has on handling that matters. And that can't be down to 'lack of under body aero effects'.

I'll put a high front/low rear tune up against any of the tuners on here and I'll limit my top speed to whatever their actual top speed is to negate the alleged 'lack of under body aero effects'... I know all the fastest drivers on here and I'm sure I can ask one or two of them to run the tunes side by side and tell us what's fastest and what feel best.

 

[TT3AZ]

Sorry, but you're wrong.

The top speed thing is irrelevent. It's the effect the ride height has on handling that matters. And that can't be down to 'lack of under body aero effects'.

I'll put a high front/low rear tune up against any of the tuners on here and I'll limit my top speed to whatever their actual top speed is to negate the alleged 'lack of under body aero effects'... I know all the fastest drivers on here and I'm sure I can ask one or two of them to run the tunes side by side and tell us what's fastest and what feel best.

Okay so you mean that all the settings for the front, is for the rear, and vice versa? I will try, and see though, im talking straight line performance, which must be simulated thru suspension settings as well.

 

[Dr_Watson]

Okay man, thank you, but how come I got similar traction and weight transfer while having front extension 10, and rear compression 10? Look at my other examples, something doesnt work out right. But I will try this things out, thanks.

Dampening has very subtle effects and are generally determined as a function of the spring tension and only really used for tuning response over bumps. You're going to find the most pronounced impact of tinkering with them if you find a kerb you'd like to run over but the car is bouncing too much and spinning out.

 

[Johnnypenso]

At the risk of becoming one of Stotty's "guys who don't know their ar$es from a hole in the ground" or something like that...lol...something just occurred to me. Earlier I read something about downforce pushing the car forward. I didn't know what that meant until I remembered this is a video game and not real life and I am assuming that what that means in GT5 is that downforce is potentially modelled as perpendicular or 90degrees to the car, not to the ground as it might be in real life although there are multiple directions of wind forces acting on real cars.

For the sake of argument and completely hypothetically, lets say a front end raised 50 mm or 2inches is roughly a 2% incline to the front and therefore in a straight line 98% of the downforce is pushing the car down and 2% is pushing the car forward say 7km/h at 300 km/h. What the real %'s are I have no idea but you wouldn't therefore notice the change in downforce in a straight line but would notice the increase in speed.

Might it not then follow that with our traditional settings by the book of a front end lower than the rear, that under braking, you start with a front end already say 25mm lower but as weight tranfers to the front, the springs compress, pitching the car forward, resulting in potentially 100mm+ or more of incline towards the front, depending on the vehicle. So if that is true, then you could have downforce acting towards the rear, pushing the car back or slowing it down (call it 1% per inch or 4% of the downforce for argument's sake) which you wouldn't notice because you are braking and trying to slow anyway, but you would also have only 96% downforce acting on the front and rear of the car.

So, it would then follow, that if you pump up the front of the car to begin with, under braking instead of the front diving 100mm as it might normally, it drops 50 mm back to horizontal and then another 50mm down, resulting in more front downforce because the car is closer to horizontal.

This could explain both the increase in speed in a straight line, and also why it might get more front end grip by boosting up the front end. Of course it doesn't gel with what happens in real life but it might fit the physics of the GT5 game engine.

Ok Stotty, be kind...lol.

 

[Sm0k3:D]

... anyone who thinks raising the front ride height is simply creating harder/softer spring rate, or that this is therefore allowing more weight transfer etc, just don't understand the fundamentals of car suspension in the real world.

Imagine a car without suspension: If you raise the front you allow more weight transfer from front end to rear end.

Raising is not creating softer spring rates, I agree with that. You just have the same rate, but more distance to travel with this rate. And this also allows weight transfer.

No_OBsT33R: I didn't testet yet. (sounds interesting). I guess if you have a harder tyre compund your top speed has to be higher than if you have a softer tyre compound, because there is less friction and resistance to move. (I'm talking about top speed in a straigh track). I'm wrong with that?

 

[nomis3613]

The top speed thing is irrelevent. It's the effect the ride height has on handling that matters. And that can't be down to 'lack of under body aero effects'.

I'll put a high front/low rear tune up against any of the tuners on here and I'll limit my top speed to whatever their actual top speed is to negate the alleged 'lack of under body aero effects'... I know all the fastest drivers on here and I'm sure I can ask one or two of them to run the tunes side by side and tell us what's fastest and what feel best.

I totally agree. The handling benefit is far more important. I was one of the people involved with the top speed testing, the purpose of it was just to better understand what is going on with the nose-up tunes.

 

[Stotty]

Ok Stotty, be kind...lol.

I understand what you're saying, but I really think there a bit too much intellectual masturbation going on here.

Front/rear transposed or the sliders working the upside down explains everything fully. Yet people are coming up with solutions that are way more far fetched than this simple explanation.

As I said in an earlier post, sometimes you just have to see what's staring you straight in the face.

Raising is not creating softer spring rates, I agree with that. You just have the same rate, but more distance to travel with this rate. And this also allows weight transfer.

No you don't... spring length is fixed, so raising the ride height does not affect the suspension travel.

 

[jack5428]

if anyones testing method seems correct to me its Nomis3613 and his cornering time tests.

its definitly about spending the least amount of time in a corner and definitly not about reaching the highest speed possible after a corner.

you can set your front to high and it will be slower because of it. drifts to much reducing mid corner speed and corner exit speed. gets to sideways basically.

for the heck of it im gonna try just ride height low as possible front and then find an ideal fastest rear on an otherwise stock tuned rally car. im guessing it might work? would most likely make it faster than stock?idk lol

funny i never thought of trying the reverse of front high rear low on a rally car.

 

[Sm0k3:D]

No you don't... spring length is fixed, so raising the ride height does not affect the suspension travel.

Wrong.

 

[Stotty]

Wrong.

When you lower a car on coilovers you don't compress the spring, you alter the position of the spring relative to the length of the damper. The spring is the same length and retains it's full travel.

 

[Johnnypenso]

I get what you're saying Stotty, I just have a hard time believing they got the front and rear ride height effects reversed. 1000 monkeys at 1000 typewriters for 1000 years and one of them will come up with the software for GT5 (I am starting to think 3 or 4 monkeys and 3 or 4 cases of beer on a long weekend....) but can't 100 guys sitting around in an office, trying to produce the greatest driving simulator the world has ever seen, figure out where the front and rear of a car is?...lol. I just find that incredible which is why I tend to look for other solutions that make sense in light of how the game may have been programmed and unintended effects from things like simplifying downforce to perpendicular to the car and not the ground.

But you're right, the simplest solution is usually the right one....lol.

 

[GTP_FastM3]

No you don't... spring length is fixed, so raising the ride height does not affect the suspension travel.

This part is confusing me. My understanding is that IRL dropping a car is often accomplished by buying shorter springs. However, I'm not really familiar with adjustable suspensions. If changing the ride height isn't changing the length of the spring, then how does it work. For GT5 how do we know that changing ride height isn't changing spring length as what happens IRL doesn't always mean that's what's happening in GT5.

 

[Stotty]

I get what you're saying Stotty, I just have a hard time believing they got the front and rear ride height effects reversed. 1000 monkeys at 1000 typewriters for 1000 years and one of them will come up with the software for GT5 (I am starting to think 3 or 4 monkeys and 3 or 4 cases of beer on a long weekend....) but can't 100 guys sitting around in an office, trying to produce the greatest driving simulator the world has ever seen, figure out where the front and rear of a car is?...lol. I just find that incredible which is why I tend to look for other solutions that make sense in light of how the game may have been programmed and unintended effects from things like simplifying downforce to perpendicular to the car and not the ground.

But you're right, the simplest solution is usually the right one....lol.

ROFL at the 1st part of your post 👍

If the only effect of high front/low rear was a touch of extra straight line speed I'd agree that the reason could be down to some sort of issue in the aerodynamic model, even though in real life, high front/low rear would actually cause the opposite. Afterall, aerodynamics are probably the most complex part of the physics engine to model.

But the reason I continue to believe the reason is much simpler than this is the handling effect... and the handling effect is far more significant than the aero.

As a final pioint before I head off to bed...

If the settings worked the other way around (low front/high rear), no one would give it a 2nd thought. The poeple who understood the basics of suspension and aeodynamics would congratulate PD on the thoroughness of the physics engine. All it needed to go wrong was a tired programmer to press - when they meant + or f when they meant r and vice versa.

What's more believable? That, or that PD have fundamental and major issue with the entire physics engine that they have spent years working on?

Unlikely that anyone would have picked up on it during testing, though it does surprise me that PD released a game in which almost every car understeers so badly stock!

 

[TT3AZ]

The suspension is flawed, at least when you accelerate, i have tried a bunch of settings, including maximizing the front extension, rear compression etc, and the only thing that increases the weight transfer is ride height maximum rear, ride height minimun front, and as soft springs as possible. Should it really be this way? How come 10 extension front, and 10 compression rear, give the same result as 1 extension front, and 1 compression rear? Hope they fix this issues thru updates and stuff. This game is some times to flawed.

 

[GTP_FastM3]

I've read the entire thread and I'm still a little unclear as to what exactly is reversed and what isn't. It seems clear that ride height is likely reversed. I've seen posted that Camber and Toe don't seem to be. I haven't seen a straight answer about bound, rebound, and Anti-Roll Bar. Any conclusions for these?

Just prior to the PSN going down I was in an online room racing M3's. I was having a hell of a time tuning out oversteer that I didn't have offline. Is it possible that online and offline are different in this regard. Or maybe that online is also backwards and that the changes I was making were affecting the front and thus making the oversteer worse.

Overall I'm now thoroughly confused as to what to do to tune a car. I was a relative newbie before. Basically I dropped it, stiffened it a little and increased camber. Mostly this has worked for me. If the car has a major issue I'll try and tweak it out, but if it drives reasonable well I leave the settings alone. I have noticed a lot of understeer in A-Spec (Not sure if it carries over to online as I don't have enough experience there to know). Maybe now I'll drop the car, check for understeer, and if present, raise the front end until it's gone.

 

[Z1-AV69]

But the reason I continue to believe the reason is much simpler than this is the handling effect... and the handling effect is far more significant than the aero.

But the handling isn't the best with nose up. It needs special settings for the other values to fix the disadvantages. Yet it's still quicker than much better handling setups.

 

[No_OBsT33R]

Sorry, but you're wrong.

The top speed thing is irrelevent. It's the effect the ride height has on handling that matters. And that can't be down to 'lack of under body aero effects'.

Sorry but I think you are wrong. I think the (I'm quite positive) there is no benefit to cornering. UNTIL you glitch tune your car, and the advantages are the minute higher speeds achievable due to lack of under car aero effects, coupled with the tail dragging braking style (they compliment each other, and are both taking advantage of the physics being simulated, not real.) I feel tuning to take advantage of physics faults is "glitch tuning". Not impressed. Don't even are if they are faster. To use it is an utter FAIL.

 

[Stotty]

Really must leave this thread alone and go to bed, but there's just so much drivel being posted!

But the handling isn't the best with nose up. It needs special settings for the other values to fix the disadvantages. Yet it's still quicker than much better handling setups.

Does it? what does it need exactly?

So far I have found absolutely no need to off set the ride height by changing other settings.

Here are my TVR Speed 12 settings (just ran a 6'58 with this car round the 'Ring on sports hards)...

Max Power: 982bhp (fully tuned, but with power limiter set to this power)

Aero: 35 61

Gears
Set top speed to 255mph then adjust individual gears as follows....
1st 3464
2nd 2271
3rd 1627
4th 1229
5th 988
6th 837
Final 3310

LSD
(on hards it doesn't really matter what you set this to as long as initial it's too high. I haven't tried adjusting it for softs yet)
5 40 5

Suspension
Ride +15 -30
Spring 17.8 16.8
Rebound 10 9
Bound 9 8
ARB 1 4
Camber 3.0 2.0
Toe -0.15 -0.25

Brakes
4 3

Other than the ride height what other settings look odd compared to a traditional tune?

Sure the LSD settings are a bit odd... but that's a reaction to the complete lack of traction even in 4th and 5th gear in a straight line.

Now go find me another tune from any of the tuning houses in the forum that HANDLES as well as this one does and doesn't use high front/low rear.

And if you can't complete a lap on sports hards (it is pretty tricky to drive and might be beyond the ability of most people), you might find it manageable on sports softs... I ran a 6.29 with the above on a 1 lap run.

Sorry but I think you are wrong. I think the (I'm quite positive) there is no benefit to cornering. UNTIL you glitch tune your car, and the advantages are the minute higher speeds achievable due to lack of under car aero effects, coupled with the tail dragging braking style (they compliment each other, and are both taking advantage of the physics being simulated, not real.) I feel tuning to take advantage of physics faults is "glitch tuning". Not impressed. Don't even are if they are faster. To use it is an utter FAIL.

'tail dragging braking style'? WTF is that?

Go build a Speed 12 tune that handles as well as the one I posted above if you're such a great tuner.

OH, and you can think whatever you like, it doesn't bother me... AND YOU CAN TYPE FAIL IN CAPITALS IF IT MAKE YOU FEEL BETTER

 

[Z1-AV69]

I never tuned a Speed12, so I can't really comment on that car. It may work there, because it is very front heavy and putting the rear lower would be a "natural" solution (at least if the settings aren't reversed ) For a rear heavy car that would be different.

 

[codybear56]

I agree with this post actually. I would look up countless websites and ask countless people how to get more grip in the front/rear. And i would generally get the same answer. Soften spring rate or dampers or etc... But when I tried it on the car, it did not work at all and if anything it got worse.

 

[Stotty]

I never tuned a Speed12, so I can't really comment on that car. It may work there, because it is very front heavy and putting the rear lower would be a "natural" solution (at least if the settings aren't reversed ) For a rear heavy car that would be different.

To fix understeer (that the TVR suffers from horrendously) you need to consider the cars 'polar moment of inertia'...

In simple terms, polar moment of inertia refers to how difficult it is to get an object to rotate on an axis. The farther away from the axis of rotation the mass is, the harder it is to make it turn.

The natual way to fix the understeer in a FR car is to shift the axis of rotation forward.

The high front/low rear setting fixes the understeer... yet the effect of high front low rear is to move the axis of rotation in the wrong direction... which would create more understeer.

Has nothing to do with 'airflow' under the car!!

 

[No_OBsT33R]

Take a chill pill.

1) to assume the physics are so fundamentally flawed is a bigger stretch then 2) some guys who has NO CLUE (those are some caps for you) how the game was programed or any details on it's programming at all, is wrong and doesn't understand the programing, he knows nothing about.....

Simplest answer is usually the best answer, that simple answer is, YOU are wrong.

Just to be clear your basing all of your assumptions off your experience in one car? Any other car that is "untunable" & only fixed with "Glitch Tuning"?

 

[Mudd]

Is it possible that lowering the car all the way is just plain limiting the suspension too much and the drawbacks just are not obvious enough so they are being overlooked? That would explain why raising the front slightly helps the handling. The reason that raising the front alot still helps would be due to the lack of under body air to counter it.
I am not claiming anyone is 'wrong', I'm just having a hard time believing that the height settings are backwards and reaching for other explanations.

 

[No_OBsT33R]

Is it possible that lowering the car all the way is just plain limiting the suspension too much and the drawbacks just are not obvious enough so they are being overlooked? That would explain why raising the front slightly helps the handling. The reason that raising the front alot still helps would be due to the lack of under body air to counter it.
I am not claiming anyone is 'wrong', I'm just having a hard time believing that the height settings are backwards and reaching for other explanations.

I agree with yah.

I believe I "agreed to disagree" but I'm "wrong"? Because some guy thinks his speed 12 handles better with retarded ride height settings?

Take it easy Stotty, yours us just an unproven theory based on assumptions, not irrefutable proof of a fundamental game defect.

 

[Z1-AV69]

The natual way to fix the understeer in a FR car is to shift the axis of rotation forward.

I have yet to develop a nose up tune myself, but what I noticed with your tunes both for the Speed12 and the MP4-12C is the rear toe. Those values produce a lot of oversteer and I don't know yet why exactly that is needed. The downside is how hard it gets to control the rear out of slow corners. As you said yourself, your Speed12 is very difficult to handle, which is imho not "good" handling.

As a sidenote: Do you get those tunes to have close to equal tyre wear front and rear? That's quite important if tyre wear is on.

Anyway, before I have to go to sleep: It might very well be that nose up benefits most cars, but each time for very different reasons. Nose up has a lot of different implications for the suspension and discussing each of them will get too far. My point is only that nose up does not generally and for all cars help with handling, but I bet it will be quicker even then.

 

[Johnnypenso]

I agree with yah.

I believe I "agreed to disagree" but I'm "wrong"? Because some guy thinks his speed 12 handles better with retarded ride height settings?

Take it easy Stotty, yours us just an unproven theory based on assumptions, not irrefutable proof of a fundamental game defect.

No offense dude but you sound like some kind of stooge or plant for Polyphony...lol. Your vehemence in the negative here, without actually making some test runs as Stotty and others have makes it's it look like you're on the GT5 payroll...lol.

Regardless of the reasons why...game engine flaws..a guy who hit "f" instead of hitting "r"...the fact remains, at least on a few of the cars I tested, keeping all my tune settings the same which I thought were great tunes, raising the front height of the car increases or creates oversteer. This does not always mean lower lap times because there are a lot more factors in total lap times than just front end grip but it does work. You need only try it on a couple of cars to see that.

I don't believe it's a question anymore of whether a higher front/lower rear creates some front end grip and, has been proven on this thread, higher top end speed, I believe those are foregone conclusions at this point. I think it's now just an academic discussion of why and of course we'll never really know why unless we get access to the game engine itself.