1.09 update physics changes....

[Zenmervolt]

I work as an auto tech, and every car I have ever worked on had more camber in the rear than the front as a factory alignment. Toe angles seem ridiculously excessive, my personal car is an S2000 and the factory alignment settings have front camber 0.0-0.6 degrees, I run 1 degree up front in my real and GT6 cars. Rear camber is 1.0-1.6, I'm lowered so I'm running 2.7, which is another thing PD effed up. When you change ride height you change static camber, and also when you run more static camber up front it changes your caster settings(which surprises me caster is not a tunable parameter). Another thing that changes is motion ratios, and roll centers, not to mention that toe also changes dynamically depending on suspension travel. I guess this would make GT6 too much sim for the kiddies. In the real world, a lot goes into suspension set up to properly control roll centers and dynamic toe changes.

Also, if I were to use the default toe settings in the game on my street car(.50 degrees) my tires would probably only last about 3,000 miles before being worn through the carcass. In real life I run 0 toe in the front, and .26 degrees of toe in the rear, which is a smidge more than dead middle of the factory adjustment range(when you have more than two degrees of rear camber a bit of extra toe will even out tire wear). Most cars I've ever worked on have .35 degrees as the upper limit for toe in the rear.

Street alignment specs have nothing at all to do with optimum track alignment. While you're right that street specs typically have more rear camber than front, that's exactly the opposite of what is optimal for track use.

For example, on my own car (modified 1986 Porsche 951) the factory alignment specs say 20' negative front camber and 25' negative rear camber (1' is 1/60 of a degree, so it comes out to -0.33 front and -0.42 rear). However, track setups use between -2.5 and -3.5 front and between -1.5 and -2.5 rear; on the track you always use more negative static camber in the front than in the rear, despite the fact that there is dynamic negative camber gain when steering because of the caster.

Street alignments are set up to make the car more stable and prevent things like lift-off oversteer and tramlining. A car with race settings will be almost unbearably twitchy on the street and that is simply not appropriate for the majority of street drivers.

And yes, cutting the springs to lower a car does increase the static negative camber. But a proper suspension refit will include parts that will negate that effect. This will cost a lot more than a set of basic Eibach (or similar) lowering springs to be sure, but it would include things like custom control arms and shorter shocks, etc.

Basically, nothing you've said has been "wrong" per se. However, you're mistakenly applying the settings common in street alignments (with their vastly different trade-offs) to track alignments and that's just not appropriate.

 

[godlameroso]

It's not a theory, in the real world it's an observable fact. Getting the right amount of toe and camber is absolutely essential to getting the most out of the contact patch. It just sucks that we can only tell what's going on with the tires by looking at the tire indicators get red or yellow. Worse still we can't even change tire pressure and things like that.

 

[Zenmervolt]

Getting the right amount of toe and camber is absolutely essential to getting the most out of the contact patch.

That's not in dispute. No-one has said anything that could contradict that.

What we have said, is that on a race alignment you want more negative static camber in the front than in the rear and that this differs from a street setup where the reverse is true.

 

[godlameroso]

If the goal is to learn, then helping others understand the difference between a 'street' alignment and a more track focused one could help them develop their tunes more appropriately. And not all setups require more front camber than rear, not all setups require a lot of camber either. I've seen it first hand tuning a real car, we got more consistent tire temperatures running lower camber in the front than in the rear with this particular car, and only after we dialed in the proper toe settings relative to the amount of camber we were using were we able to control the tire wear. You can't just say more camber in the front than in the rear will always be better. Unfortunately we can only do things by trial and error in this game, there is no viable tuning solution because we lack information needed to tune properly.

 

[DolHaus]

You are both right, the more aggressive setup will suit the majority of tuners who are looking for raw speed and the real life background will help those looking to make replica style street cars.
As for which is actually better is dependent on a whole lot of other things and there really is no right or wrong answer.

Either way, good to hear new theories, ideas and experiences 👍

 

[Zenmervolt]

If the goal is to learn, then helping others understand the difference between a 'street' alignment and a more track focused one could help them develop their tunes more appropriately.

Which is why we're pointing out that your recommendations apply only to street setups, not to track setups. Something you failed to do.

And not all setups require more front camber than rear, not all setups require a lot of camber either.

While it is possible that in certain cases a driver may prefer a car with more rear static negative camber than front static negative camber (in my real life track experience this has always been in cases where the car was very loose in steady-state cornering and the driver needed to dial out some of the oversteer by adding static negative camber in the rear), such cases are very rare. Every track setup guide I've seen starts with at least 0.5 degrees more static negative camber in the front than in the rear.

As a starting point for a track alignment (which is the only alignment you'd be using in the game), it does not make any sense to start out with more rear static negative camber than front.

You can't just say more camber in the front than in the rear will always be better.

Not "always," but better than 90% of the time. More rear camber is great if you need to tighten the car up a little, but that's rarely the case unless you're driving something like an old 911 (964 or earlier as even 993s use slightly more front camber than rear in track setups).

Unfortunately we can only do things by trial and error in this game, there is no viable tuning solution because we lack information needed to tune properly.

True, but the starting point should be one that is close to what most cars will need. And for track use (which is what this game is about) that's going to be slightly more front negative static camber than rear.

 

[meek]

When you lower a car, you compress the suspension geometry the lower arm moves up more than the upper arm and essentially becomes longer than the upper arm, this moves the bottom of the wheel outward causing more camber. Once you lower a car it cannot be aligned back to factory specs unless you get custom control arms. Generally you don't add much toe out unless it's a front or all wheel drive vehicle. Also lowering a car affects the suspension motion ratio, meaning the suspension movement begins to influence damper motion to a higher degree.

You run toe in on a wheel cambered more than two negative degrees to reduce tire wear, again this is a general rule of thumb, and there is a window where it helps, and where it starts making things difficult.

toe-in I use toe out (negative toe) in GT6 to help with tire wear. I've asked a mechanic and he told me the GT6 toe description was spot on (toe-in=more stability & more understeer, toe-out=less stability more oversteer, IIRC), I guess that effect isn't? toe-in is bad for tire wear in GT6.
Quick search turns in "Wear on the outside edge of the tyre : incorrect toe-in, wear on the inside edge of the tyre : incorrect toe-out" which makes plenty of sense but doesn't seem applicable to GT...

Can you or another knowledgeable fellow answer this, too: is it possible to create unequal camber in GT6? (I want negative camber on left side wheels, positive on the right).
Love those threads btw, you learn a lot, when you understand any of it... lol

 

[DolHaus]

is it possible to create unequal camber in GT6? (I want negative camber on left side wheels, positive on the right).
Love those threads btw, you learn a lot, when you understand any of it... lol

Not really unfortunately, the amount of positive camber you gain under full extension in game is minimal at best even when taken to extremes.
You will get different negative angles on inside and outside wheel during cornering but not to the extent you are looking for. To obtain actual positive camber in game you would have to encourage a ridiculous amount of body roll during cornering which would kill any positives.

 

[meek]

Not really unfortunately, the amount of positive camber you gain under full extension in game is minimal at best even when taken to extremes.
You will get different negative angles on inside and outside wheel during cornering but not to the extent you are looking for. To obtain actual positive camber in game you would have to encourage a ridiculous amount of body roll during cornering which would kill any positives.

Even in a banked corner? or a better question might be, on a car with zero camber front or rear, in a banked turn, does the inside wheel have positive camber? (in GT6 and IRL)
Why "unfortunately" if you don't mind me asking, you like NASCAR too?

To get the most body roll, do I put ARB on 1/1 or 7/7?

I just realized something regarding my previous post, despite it not showing up, tyres do wear unevenly. With no toe front or rear, I couldn't last 6 laps, adding some toe-out in the rear helped me last 6.5 laps.
That means my inside tyres were producing toe-in and wearing out the outside part of my tyres, correct? is this normal, realistic?

 

[rams1de]

I'm getting a feeling of déjà vu

 

[DolHaus]

Even in a banked corner? or a better question might be, on a car with zero camber front or rear, in a banked turn, does the inside wheel have positive camber? (in GT6 and IRL)
Why "unfortunately" if you don't mind me asking, you like NASCAR too?

To get the most body roll, do I put ARB on 1/1 or 7/7?

As far as I'm aware no cars in GT6 gain useful amounts of positive camber under normal circumstances during full extension. To gain the desired effect even on a cambered bend you would have to severely limit your tune in other ways. I can't speak for Nascars as I don't drive them or banked tracks very often, you can check for yourself though by using photo mode, I would suspect that they don't replicate real world geometry as it would make them unusable on normal circuits.

I'm not a Nascar fan , I appreciate the spectacle and skill but its not my kind of motor sport really, too long and not enough variety for my tastes.

Most body roll would be encountered with low ARB settings and Soft springs/dampers while running a high ride height.

 

[Voodoovaj]

Rear camber is 1.0-1.6, I'm lowered so I'm running 2.7, which is another thing PD effed up. When you change ride height you change static camber, and also when you run more static camber up front it changes your caster settings(which surprises me caster is not a tunable parameter). Another thing that changes is motion ratios, and roll centers, not to mention that toe also changes dynamically depending on suspension travel. I guess this would make GT6 too much sim for the kiddies. In the real world, a lot goes into suspension set up to properly control roll centers and dynamic toe changes.

It isn't "f'd" up (though I guess that is a perspective thing). On a real car, the suspension attaches the wheels to the rest of the car. There are actual, physical arcs of movement and adjustment limitations. Every car is different. You can also relocate connection points, arm length, etc.

In the game, the suspension is completely virtual. That's why you can have pretty much the same range of adjustment on all cars (aside from ride height).

This is why real world numbers are irrelevant.

 

[Le_Manuz]

That's similar to how it get my initial spring settings based on the weight split of the car, but I factor in the quality of tires as well. (Lesson learned from Trackripper123 in GT5 with a little modifying for GT6) Comforts are around 25-40% of the available slider. Sports are 40-55% of the available slider. And Racing tires are in the stiffer 60-75% of the available slider range. Then adjust accordingly based on what the car is doing or what you want it to do, but I try not to venture outside of those ranges. If I have to, I must have messed something up somewhere. I'll have to try your precise method and see how it goes for me. Nice job!

I really like both of your post and i wonder if it can also be extended to final gear of transmission
(motor torque/vehicle mass) ratio vs tire grip factor with the final gear in between ?

 

[Lionheart2113]

I really like both of your post and i wonder if it can also be extended to final gear of transmission
(motor torque/vehicle mass) ratio vs tire grip factor with the final gear in between ?

I apologize, but I guess I'm not understanding your question. The post that you quoted was just a little trick for initial adjustments on spring stiffness, but it sounds like your question was leaned more towards transmissions. I'm still in the learning phase of transmissions so I wouldn't be a huge help. I'm still trying to figure out why a car handles differently when the only difference is 1st gear, yet 1st gear is never used on that particular track. @GTP_CargoRatt would be a great person to ask.

 

[Otaliema]

I really like both of your post and i wonder if it can also be extended to final gear of transmission
(motor torque/vehicle mass) ratio vs tire grip factor with the final gear in between ?

In regards to transmissions. Once you understand them they are pretty easy to use. The guides I learned the basics from, are the one from @praiano63 located *gt6 version* here and the guide by @Master__Shake_ located here.
I've added my own techniques to what I learned from these. They basically boil down to what kind of transmission are you after. Top speed, Acceleration, Balanced or some place in between them? This dictates the starting point of the Final gear, and placement of TS slider. The size of each gear should use the largest section of the power band you will gain the most acceleration in or hold your top speed at.

The transmission is always the last or second to last part of the car that i finished. I would encourage devolving a testing transmission for each type of set up you will be using, that way you can have a closer to finished product during testing to help set the diff and the suspension.

 

[Le_Manuz]

I already used those method to setup a gearbox and finally step aside of it
i only kept the good spreading system which is a natural way to do it

for a few weeks i based my method to first setup the final gear based only on motor torque value
if it's high i set it all the way right, if it's low the opposite
it gives me good results

the method i try to go with now is to first setup the final gear depending on the combination of Motor Torque, Car Weight and Tire grade
but would like to find a good formula
for ex:
for a car with low torque/weight ratio on racing soft, i put the final gear all the way left (but maybe on comfort hard it won't be all the way right)
for a car with high torque/weight ratio on comfort hard, i put the final gear all the way right (but maybe on racing soft it won't be all the way left)

then i setup the final speed
test the first gear and set it like in their method, to keep the balance between burnout start and not too much revs drop
setup the second gear accordingly to the slowest track curve
then spread correctly the remaining gears but not the last one

maybe i don't have to keep in mind the torque/weight ratio as when you change motor output by adding/removing performance parts
and touch the final gear, it change the gears ratio
keep it simple, final gear from left to right is from 0% to 100% and do this
RS is 0% of the final gear
RM is 12,5%
RH is 25%
and so on to finish with comfort hard is 100% of final gear

what do you all think about that ?
i'm going into a wrong way, dead end issue ?

 

[Otaliema]

I already used those method to setup a gearbox and finally step aside of it
i only kept the good spreading system which is a natural way to do it

for a few weeks i based my method to first setup the final gear based only on motor torque value
if it's high i set it all the way right, if it's low the opposite
it gives me good results

the method i try to go with now is to first setup the final gear depending on the combination of Motor Torque, Car Weight and Tire grade
but would like to find a good formula
for ex:
for a car with low torque/weight ratio on racing soft, i put the final gear all the way left (but maybe on comfort hard it won't be all the way right)
for a car with high torque/weight ratio on comfort hard, i put the final gear all the way right (but maybe on racing soft it won't be all the way left)

then i setup the final speed
test the first gear and set it like in their method, to keep the balance between burnout start and not too much revs drop
setup the second gear accordingly to the slowest track curve
then spread correctly the remaining gears but not the last one

maybe i don't have to keep in mind the torque/weight ratio as when you change motor output by adding/removing performance parts
and touch the final gear, it change the gears ratio
keep it simple, final gear from left to right is from 0% to 100% and do this
RS is 0% of the final gear
RM is 12,5%
RH is 25%
and so on to finish with comfort hard is 100% of final gear

what do you all think about that ?
i'm going into a wrong way, dead end issue ?

Honestly your over complicating the transmission for general use, if your building a hot lap tune your pretty much spot on. other than the Final gear set up part.

The final gear starting point basically determines if you have an acceleration or top speed transmission.
Acceleration transmissions start on middle lower 25% while Top speed start all the way right.
Your top speed slider is used in combination with, tire type, max horse power and torque, and maximum top speed of the car with the in use parts on the longest straight.
So far for me in GT6 as a general rule with acceleration transmissions. a Final gear starting 0.800 from the lowest number will once stretched equals the speed of the top speed slider. ie I set the slider at 260 km/h I get 255-265 km/h after building. I use longer indivual gears with this to maxiumize the power and time in each gear and reduce wheel spin.
If i'm setting up a general use transmission I will set the Final at the mid point and set the ts slider as far left as I can go with out running out of speed in 5000 km at SSR-X.
Top speed I set far right, set the TS slider as high as I can get it with out running out of power by the end of 10k km on SSRX.
Than in both cases smooth out the gears to be a nice smooth curve up.

 

[DolHaus]

My thoughts are that both active camber and active toe are having an effect on the contact patch modelling, we are seeing varying results during various stages of cornering as a result of this. These certainly have an effect on the overall characteristics of a car depending on how these parameters are utilised or controlled.
I dismiss the notion of it being simple and dumbed down as we rarely see all covering solutions to tuning problems, a certain fix on one car will not translate to another. The exception being ride height where we are seeing a simplified physics model and hence get sweeping solutions with definable amounts of change.