General Tuning Guide (Updated 1.09)

[DolHaus]

@DolHaus did you make the contact patch graphics yourself or pull those from a tuning book. I think the way that you are showing the tire contact patch is a bit misleading. This is what I would expect to see.

Plus, showing the contact patch for the wheels in straight line position is less relevant that showing contact patches with the wheel turned and the vehicle under load. Maximizing grip with camber is most important under that condition.

I did the all the pictures myself using MS Paint (detail is not exactly an option), they are only there to illustrate a point anyway and shouldn't be taken as gospel. This thing took me a solid week to get put together, I'm not good with computers

For the most part yeah, and it comes with pretty pictures! Was just a little concerned that the oval shown for the contact patch might be a little skinny showing different ratios. But I'm not 100% sure of that, so don't worry too much based on what I say. It looks great @DolHaus and I appreciate all of the work you put into it and I'm sure others will too.
You should have told me you needed drawings...I've got the 3 views of an Aston Martin drawn on ACAD, that was a 🤬 to draw in that program. I'll be reading and re-reading this for the next week!!👍

Ahh CAD, I haven't used those kind of programs in years. I remember they had amazing abilities and promise but were always just a little bit too complicated to be fun lol

Well done! Thank you! Im sure many people will find this very useful. And coming from someone that understands very little of the tuning aspect of this game, i say that ur guide is very understanding and easy to apply!
Thanks again @DolHaus xoxo❤️

You are welcome, hope it makes sense for you

 

[sgr]

I appreciate the research U do. It makes me really see how bad a job I did trying to build a fast car from the ground up. Your work has given me a better understanding of physics. real world physics. Now trying to apply it to gran turismo physics is quite a challenge considering for every update u dont know what will change.

 

[DolHaus]

I appreciate the research U do. It makes me really see how bad a job I did trying to build a fast car from the ground up. Your work has given me a better understanding of physics. real world physics. Now trying to apply it to gran turismo physics is quite a challenge considering for every update u dont know what will change.

Thank you, I'm glad I could help you gain a better understanding and I hope it helps you to build the cars you want in future.
We have to keep learning and adapting with every update, I think that will be the last big physics update for a while as I can't really think of anything else that really needs fixing.

 

[DriftinAssassin]

Time to give this a new look over and get back to tuning in my garage. Thanks for all the hard work and research just to help out the tuning community!

 

[sgr]

IMO more front camber more snap towards oversteer. Great for 4wd. More rear camber more support to assist understeer. great for MR drive. more Equal camber more balanced snap exiting corners if that makes sense. example: I tried high front camber for the arta gariya and low speed corners it would spin everytime. but more rear camber much easier to drive.

 

[DolHaus]

Time to give this a new look over and get back to tuning in my garage. Thanks for all the hard work and research just to help out the tuning community!

No worries, glad to help

IMO more front camber more snap towards oversteer. Great for 4wd. More rear camber more support to assist understeer. great for MR drive. more Equal camber more balanced snap exiting corners if that makes sense. example: I tried high front camber for the arta gariya and low speed corners it would spin everytime. but more rear camber much easier to drive.

I'm going to be setting up some tests as soon as I can to start trying to find some more answers, as with all tuning techniques certain methods will come to light in time. At the moment everyone is coming up with ideas and theories which is great but I think it is too early to say anything for sure, there's a lot of variables to identify and understand first:tup:.

 

[sgr]

Yes id like to know what suspension techniques are used to compliment camber and what the effects of weight distribution has on the way camber is set up. ex top heavy and rear heavy and downforce. I still am not sure how toe affects camber. Its way over my head. I got handling changes using camber but the fine tuning of it to bring out the best of the suspension is best left up to someone with more refined expertise.

 

[GTP_Richtofen]

Hey @DolHaus i had a question i was seeing if you could help me out. And i know you are busy so no rush to getting back to me. Its not very important so i can wait till you have the time.
But,,, i can not figure out what settings to mess with for the Lotus Elise '11 to get it to behave. Idk the right terminology to explain this better, but i feel like it snap to the side when i try to turn sharp. I can not get it to smoothly go into a turn and out. almost feels like the weight balance is 10 : 90 or something like that. Im sure if you have this car and rive it you would understand what I'm talking about.
Thank you❤️

 

[Robbks]

MR cars are typically "snappy" like that
There's a fine balance between keeping the rear end stiff enough to handle the extra weight of the engine back there, but not too stiff that it starts to reduce grip.
Generally (NOTE: I haven;'t tuned an Elise in GT6) I've found a balance of "reasonably" stiff anti-roll bars which helps to stop too much weight transfer
but not too stiff springs to keep the grip on the tyres.
then you have the problems with Camber and toe to deal with.
I've usually found you can run a fair bot of rear toe-in which helps tame the rear end a bit too.

 

[DolHaus]

Hey @DolHaus i had a question i was seeing if you could help me out. And i know you are busy so no rush to getting back to me. Its not very important so i can wait till you have the time.
But,,, i can not figure out what settings to mess with for the Lotus Elise '11 to get it to behave. Idk the right terminology to explain this better, but i feel like it snap to the side when i try to turn sharp. I can not get it to smoothly go into a turn and out. almost feels like the weight balance is 10 : 90 or something like that. Im sure if you have this car and rive it you would understand what I'm talking about.
Thank you❤️

Ok, the first and easiest way would be to gradually raise the rear ride height above the front. This will move the centre of gravity forwards (towards the front axle) and make the car harder to rotate and more stable as a result. Bit of a quick fix really, I try to avoid relying on this trick too much as you can end up with a really numb feeling car.

Next option is the springs/dampers, increasing the spring rates will slow the lateral weight shift of the car and make it more controlled. Try playing with the dampers first if you want to avoid messing with the balance too much. If the car seems to be transferring weight too quickly on turn in then increase the compression, if its giving you problems on exit then increase the extension.
If that doesn't handle it then try stiffening the front springs or softening the rear. The easiest way to think about them is that stiffening the front will decrease rotation and stiffening the rear will increase it.

Which tyres are you running? If you put grippier tyres on the car then you will need to increase the stiffness of the suspension in order to control the weight shift better. Cars running on less grippy tyres run softer suspension in order to try and reduce the load transferred to the tyres and make oversteer progressive. High grip tyres need stiffer suspension because the tyres can take more force acting upon them, the suspension is then trying to reduce body roll in order to stop it pulling the car wide in turns.

The ARBs are a little bit tricky to explain, they won't really affect the rotational balance of the car but more how the car handles weight transfer while rotating. Their most noticeable effect is the way the car transfers from grip to oversteer, low settings will allow weight to transfer quickly from one side to the other, if you set it too low it will throw the weight around in an uncontrolled manner, high settings will slow it down but if set too high will make it instantaneous and unforgiving.

I'll leave toe out of it for the minute as I don't really think it will help in this instance.

One of the most influential parts is the LSD, try raising the Initial to make rotation a little less aggressive and controlled. If it is set too low then the car will be very sharp and easy to turn in but can quickly change to over rotation if you are not precise with your steering and throttle inputs.
I've copied some diff tuning tips from earlier in the thread that explain what to do

Initial setting: This is easiest to analyse when the car is rolling without throttle or braking applied. Take it into a corner, lift off and turn in, concentrate on how the back end of the car feels in terms of rotation. If it doesn't want to turn then the number is too high, if it feels loose and unstable then the number is too low. This setting also affects how aggresively the Diff kicks in but I will cover that below.

Acceleration sensitivity: This is easiest to analyse coming out of a corner with full throttle applied. Concentrate on how the rear wheels behave when accelerating out of a bend. If the car pushes wide on exit or spins the tires up then the number is too high, if it feels like its lacking power and/or spins the inside rear tyre then the number is too low.

Braking sensitivity: This is easiest to analyse coming into a hard braking zone whilst turning. Concentrate on how the rear wheels behave under braking conditions and how much rotation is possible during the act. If the car won't turn then the number is too high, if it feels loose and unstable then the number is too low.

Which tyres are you running? If you put grippier tyres on the car then you will need to increase the stiffness of the suspension in order to control the weight shift better. Cars running on less grippy tyres run softer suspension in order to try and reduce the load transferred to the tyres and make oversteer progressive. High grip tyres need stiffer suspension because the tyres can take more force acting upon them, the suspension is then trying to reduce body roll in order to stop it pulling the car wide in turns.

Try and change just one setting at a time for both suspension and LSD tuning, that way you can isolate and identify the problem efficiently. If you change a whole bunch of settings you could easily fix the original problem by changing one parameter and then cancel that fix by changing another, then you'll end up getting further and further from a solution without understanding why.

The elise has never been one of my favourite cars, I respect its abilities and potential performance but its not my sort of car really, works really well for some driving styles but not for mine unfortunately. I like a car that needs to be run close to the edge constantly but won't kill you if you push too hard, the elise always struck me as needing a very precise and measured driving technique to get the best from.

If I get the chance to have a look at the car then I will let you know, but this should help you find a solution in the mean time.

 

[Thorin Cain]

View attachment 129253

Camber Settings -​

​

Used to describe the vertical angle of the wheel in relation to the ground. Negative (-) camber means that the bottom of the wheel sticks out further than the top which generally provides more grip when cornering as it puts the wheel at a better angle to the road. Positive (+) camber is generally only used on agricultural and off-road vehicles and doesn't provide any advantages to a race set-up.

View attachment 177805


Camber is quite complicated in the way it works but the basic idea is that running a wheel at an angle to the road will change the way the tyre contacts the road and affects how much stress it can sustain in any particular direction.


View attachment 177806


Here we see a wheel at 0.0 degrees of camber, the contact patch is wider than it is long which means it can handle more lateral (sideways) forces but less linear (accelerating/braking) forces. This makes it ideal for cornering.


View attachment 177807

Here we see a wheel with heavy negative camber. The contact patch is now longer than it is wide which makes it better at handling linear (accelerating/braking) forces but worse at handling lateral (sideways) forces. This makes it ideal for accelerating and braking.

What are the major points to consider when tuning my car with camber?


Overall aim – We are aiming to use camber to get the best possible contact patch on the road at any given moment. We want it to be leaning on the inside edge of the tyre when travelling in a straight line and spreading the load when cornering to give us the most useful grip when we need it.


Camber angle – There is no such thing as a perfect angle for all cars and all conditions. Pick a sensible number in relation to the fitted tyres, set it equally at both ends of the car. Take the car for a few laps and see how it performs. Increase or decrease the numbers equally and try again, if it performs better then keep moving in that direction, if it feels worse then try the other way. Once you feel you've found the best number, try adjusting the front and rear independently and look for any improvements. Sometimes the best results will be with equal front and back, sometimes it will be better when they're at vastly different figures, it all depends how your car is setup and what you want it to do.


Tyres- Different types of tyres work better between certain values in the same way that springs do.

Comfort: Between 0.0 - 2.0
Sport: Between 1.0 -3.0
Racing: Between 2.0 - 4.0​

Active camber: When the suspension is compressed the wheels gain negative camber and conversely during extension they gain positive camber. This means the angles will change constantly as the suspension tries to keep the wheels on the track.


Ride height - This setting may be called ride height but in this context it should be treated more like the amount of suspension travel. The higher the ride height, the more the suspension geometry will change and add negative camber during compression. The lower the ride height, the more constant the angles are.


Springs/Dampers/ARB - Much like the ride height, these settings will directly affect how much active camber is gained during compression by controlling the amount of movement in the suspension. As before stiffer settings will reduce the amount of geometry change and softer settings will increase it.


Toe angle – When we change the angle of a wheel in one axis we affect other settings that also rely on angles to perform. Toe angles may change in feel when camber is applied and may also need adjusting. My general thought would be to reduce toe angle as more camber is applied.


Track Surface: If the track you are racing on has banked/cambered corners then you may wish to run a little less camber than you would on a flat track in order to maintain your contact patch.


Rim Size - I'll only mention this briefly as I cannot confirm or deny if it is modelled in the game. The theory is that a the taller tyre sidewall that you would find on a standard size rim is more flexible and easier to deform than the shorter stiffer sidewall you would have on a +2” rim. Always worth checking when you are looking to put the finishing touch on your setup.



(Research is currently ongoing into the application of camber and I will update the guide as more obvious trends and tuning patterns appear)

Toe settings -​

Front toe in (+ Slider to the right)


Pros: Improved straight line stability. Increased mid corner grip

Cons: Reduced grip on turn in



Front toe out (- Slider to the left)


Pros: Increased grip on turn in

Cons: Less stable at speed. Reduced mid corner grip.



Rear toe in (+ Slider to the right)


Pros: Reduced lift off/power oversteer

Cons: Reduced lift off/power oversteer



Rear toe out (- Slider to the left)


Pros: increased lift off/power oversteer

Cons: increased lift off/power oversteer



A combination of front toe in (+) and rear toe out (-) can make a car easier to turn, this work well on FF layout cars.

Very nicely done! 👍

Thanks for taking the time and putting in all that effort into this. It is another well explained and I think fairly easy to follow segment of your guide. I am sure this will help a lot of people out there(Myself included.) to better understand how camber and toe can be used together to achieve the balance they/we are looking for.

I do have a quick follow up though....Come on! You knew it was coming....

In relation to your thought about reducing toe angles as camber is applied. As using camber adds stability to the end of the car at which it is applied, would you recommend that both toe in and toe out be reduced? Or would you reduce one and increase the other?

 

[DolHaus]

Very nicely done! 👍

Thanks for taking the time and putting in all that effort into this. It is another well explained and I think fairly easy to follow segment of your guide. I am sure this will help a lot of people out there(Myself included.) to better understand how camber and toe can be used together to achieve the balance they/we are looking for.

I do have a quick follow up though....Come on! You knew it was coming....

In relation to your thought about reducing toe angles as camber is applied. As using camber adds stability to the end of the car at which it is applied, would you recommend that both toe in and toe out be reduced? Or would you reduce one and increase the other?

It would depend on what the Toe was doing in the first place, if it was there to improve rear stability and was now not needed then I would bring the toe closer to 0 in the same way I would if I adjusted my springs and ended up with a more stable setup.
If I was using the front toe to improve rotation then I would try both increasing and decreasing the values to see what happened, there isn't really an applicable standard process in those circumstances. Its more a case of the scale changing than the function, because you have changed the vertical angle of the wheel you have also altered the way toe works, it may now be doing more or less than before depending on your other angles.

 

[turismoslayer]

@DolHaus, been hanging around your thread here for a while and thought I'd pipe in and say thanks for your hard work and what seems to be a passion for sharing your insight with the community. It's also assuring to see that you also take part in discussions throughout the tuning forums and are learning from others as well. Your humble approach to teach us in a simple way is top notch. Yeah that was a little cheesy. Anyways, cheers!

 

[DolHaus]

@DolHaus, been hanging around your thread here for a while and thought I'd pipe in and say thanks for your hard work and what seems to be a passion for sharing your insight with the community. It's also assuring to see that you also take part in discussions throughout the tuning forums and are learning from others as well. Your humble approach to teach us in a simple way is top notch. Yeah that was a little cheesy. Anyways, cheers!

Thank you for your kind words, I appreciate it.
I need to stay actively involved with the forums in order to help myself learn and to hopefully help others to understand the game. It hasn't made me popular with some folks along the way but such is life, can't win them all

 

[Lionheart2113]

It hasn't made me popular with some folks along the way but such is life, can't win them all

Truer words can't be spoken...or typed in this case! I still say good job!👍

 

[GTP_Richtofen]

Ok, the first and easiest way would be to gradually raise the rear ride height above the front. This will move the centre of gravity forwards (towards the front axle) and make the car harder to rotate and more stable as a result. Bit of a quick fix really, I try to avoid relying on this trick too much as you can end up with a really numb feeling car.

Next option is the springs/dampers, increasing the spring rates will slow the lateral weight shift of the car and make it more controlled. Try playing with the dampers first if you want to avoid messing with the balance too much. If the car seems to be transferring weight too quickly on turn in then increase the compression, if its giving you problems on exit then increase the extension.
If that doesn't handle it then try stiffening the front springs or softening the rear. The easiest way to think about them is that stiffening the front will decrease rotation and stiffening the rear will increase it.

Which tyres are you running? If you put grippier tyres on the car then you will need to increase the stiffness of the suspension in order to control the weight shift better. Cars running on less grippy tyres run softer suspension in order to try and reduce the load transferred to the tyres and make oversteer progressive. High grip tyres need stiffer suspension because the tyres can take more force acting upon them, the suspension is then trying to reduce body roll in order to stop it pulling the car wide in turns.

The ARBs are a little bit tricky to explain, they won't really affect the rotational balance of the car but more how the car handles weight transfer while rotating. Their most noticeable effect is the way the car transfers from grip to oversteer, low settings will allow weight to transfer quickly from one side to the other, if you set it too low it will throw the weight around in an uncontrolled manner, high settings will slow it down but if set too high will make it instantaneous and unforgiving.

I'll leave toe out of it for the minute as I don't really think it will help in this instance.

One of the most influential parts is the LSD, try raising the Initial to make rotation a little less aggressive and controlled. If it is set too low then the car will be very sharp and easy to turn in but can quickly change to over rotation if you are not precise with your steering and throttle inputs.
I've copied some diff tuning tips from earlier in the thread that explain what to do

Initial setting: This is easiest to analyse when the car is rolling without throttle or braking applied. Take it into a corner, lift off and turn in, concentrate on how the back end of the car feels in terms of rotation. If it doesn't want to turn then the number is too high, if it feels loose and unstable then the number is too low. This setting also affects how aggresively the Diff kicks in but I will cover that below.

Acceleration sensitivity: This is easiest to analyse coming out of a corner with full throttle applied. Concentrate on how the rear wheels behave when accelerating out of a bend. If the car pushes wide on exit or spins the tires up then the number is too high, if it feels like its lacking power and/or spins the inside rear tyre then the number is too low.

Braking sensitivity: This is easiest to analyse coming into a hard braking zone whilst turning. Concentrate on how the rear wheels behave under braking conditions and how much rotation is possible during the act. If the car won't turn then the number is too high, if it feels loose and unstable then the number is too low.

Which tyres are you running? If you put grippier tyres on the car then you will need to increase the stiffness of the suspension in order to control the weight shift better. Cars running on less grippy tyres run softer suspension in order to try and reduce the load transferred to the tyres and make oversteer progressive. High grip tyres need stiffer suspension because the tyres can take more force acting upon them, the suspension is then trying to reduce body roll in order to stop it pulling the car wide in turns.

Try and change just one setting at a time for both suspension and LSD tuning, that way you can isolate and identify the problem efficiently. If you change a whole bunch of settings you could easily fix the original problem by changing one parameter and then cancel that fix by changing another, then you'll end up getting further and further from a solution without understanding why.

The elise has never been one of my favourite cars, I respect its abilities and potential performance but its not my sort of car really, works really well for some driving styles but not for mine unfortunately. I like a car that needs to be run close to the edge constantly but won't kill you if you push too hard, the elise always struck me as needing a very precise and measured driving technique to get the best from.

If I get the chance to have a look at the car then I will let you know, but this should help you find a solution in the mean time.

THANK YOU!❤️❤️❤️
Don't have the time to give you a proper post back yet @DolHaus. With all the time u spent replying to me i want to give you back equal amount of feedback from testing and what i found out. but when i have time. Hopefully 2mrw.
oh I'm using Sport : hard/Med/Soft
Thanks again. I promise i will get back to you ASAP! ur the best!xoxo

 

[DolHaus]

THANK YOU!❤️❤️❤️
Don't have the time to give you a proper post back yet @DolHaus. With all the time u spent replying to me i want to give you back equal amount of feedback from testing and what i found out. but when i have time. Hopefully 2mrw.
oh I'm using Sport : hard/Med/Soft
Thanks again. I promise i will get back to you ASAP! ur the best!xoxo

I'm sure the data from your findings will be useful for both your own learning and others facing similar problems

 

[Le_Manuz]

Your Pro/con of rear toe is the same, i guess it's not right
do you have any figures of decent amount of toe for different car type and a little description?

like
4WD : +10 front -5 rear (help to make the 4WD to turn, toe angles of the external wheels are" tangentials" of a circle (the curve) )

?

 

[DolHaus]

Your Pro/con of rear toe is the same, i guess it's not right
do you have any figures of decent amount of toe for different car type and a little description?

like
4WD : +10 front -5 rear (help to make the 4WD to turn, toe angles of the external wheels are" tangentials" of a circle (the curve) )

?

They are both the same because the same trait can be positive or negative depending on what you want the car to do. I do need to add some extra notes to it though so thanks for reminding me.

I don't quite understand your question though unfortunately?

 

[Aussie_HSV]

@DolHaus Hi mate, thanks for all your efforts with this guide. It's awesome stuff and I've learnt a lot from it.
But I now come crawling on hands and knees looking for further advise.

I've found my nemesis ... it goes by the name of Audi R8 LMS ultra (Team Phoenix)
I've thrown everything at this beast and have basically failed on every attempt.
While I can get it to perform very well around 90% of almost any track, once it gets near a slow corner, and I mean any slow corner, all it wants to do is turn it's back and run.

The most success I've had keeping the back-end in check is by using the lightest touch of throttle while cornering.
But more often than not I use too little or too much and the car still turns 180 degrees.
It's not a viable technique trying to run consistant laps during an enduro.
If I'm going to spin out every second lap I may as well not bother.

The only other success is by basically coming to a stop.
This at least stops the car from spinning.
But obviously a killer for lap times.

Frankly, I've run out of things to try, and hair to pull out.
640PP limit and any tyres.
I've looked at all variations of power output and all tyre types.
Power delivery seems almost moot, and RS tyres are the clear winner.
(Deg. is set to 'normal' so wear isn't a major factor, keeping this beast straight is)

Been there and done that with essentially everything.
Ride heights : high/low/reversed.
Suspension: all stiff/all soft/stiff front, soft rear
Zero camber, to low, to mid., to high.
Small toe and huge chunks of it.
Ballast: forward and back.
Aero: min/max/blends
LSD: doubt there's a combo I haven't tried.

This car is doing my head in.
It drives beautifully at speed, smooth as the proverbial.
But put it near any first or second gear corner, and this car swings around like a pendulum.

I would greatly appreciate any tips, (doesn't even have to be R8 specific, just a general trouble shoot), any tips at all, about how to stop this ridiculous slow speed washout of the back-end.

Cheers.

(P.S. Sorry about the novel)

 

[Le_Manuz]

that's not only that car which have that behavior at slow speed corner
hsv, nsx LM race car do that too
i find it totaly unrealistic , what ever you do (slowing down, throttling, accelerating slowly) it have the same reaction
i don't remember exactly but only do that under a certain speed, above it's stable

@DolHaus, by car type i mean transmission type
like in my example

 

[DolHaus]

@DolHaus Hi mate, thanks for all your efforts with this guide. It's awesome stuff and I've learnt a lot from it.
But I now come crawling on hands and knees looking for further advise.

I've found my nemesis ... it goes by the name of Audi R8 LMS ultra (Team Phoenix)
I've thrown everything at this beast and have basically failed on every attempt.
While I can get it to perform very well around 90% of almost any track, once it gets near a slow corner, and I mean any slow corner, all it wants to do is turn it's back and run.

The most success I've had keeping the back-end in check is by using the lightest touch of throttle while cornering.
But more often than not I use too little or too much and the car still turns 180 degrees.
It's not a viable technique trying to run consistant laps during an enduro.
If I'm going to spin out every second lap I may as well not bother.

The only other success is by basically coming to a stop.
This at least stops the car from spinning.
But obviously a killer for lap times.

Frankly, I've run out of things to try, and hair to pull out.
640PP limit and any tyres.
I've looked at all variations of power output and all tyre types.
Power delivery seems almost moot, and RS tyres are the clear winner.
(Deg. is set to 'normal' so wear isn't a major factor, keeping this beast straight is)

Been there and done that with essentially everything.
Ride heights : high/low/reversed.
Suspension: all stiff/all soft/stiff front, soft rear
Zero camber, to low, to mid., to high.
Small toe and huge chunks of it.
Ballast: forward and back.
Aero: min/max/blends
LSD: doubt there's a combo I haven't tried.

This car is doing my head in.
It drives beautifully at speed, smooth as the proverbial.
But put it near any first or second gear corner, and this car swings around like a pendulum.

I would greatly appreciate any tips, (doesn't even have to be R8 specific, just a general trouble shoot), any tips at all, about how to stop this ridiculous slow speed washout of the back-end.

Cheers.

I have heard that the Phoenix R8 LMS is just one of those difficult cars unfortunately. Everyone says the same thing about it.
I'm not sure I'll be able to solve that one for you but I will put up some general tips just in case 👍

When dealing with power oversteer my first port of call would be the LSD, my aim is to smooth out power delivery as much as possible in order to prevent inducing load peaks. A load peak can occur when the drive wheels go from one phase to another ie. coming off the brakes and rolling the car in neutral before getting back on the gas to power out.
The differential is set to allow the powered wheels to spin at different speeds during these phases so if the speeds are too different it is like either braking the outside wheel or releasing the inside wheel. These can both cause a sudden loss or increase in grip on one wheel which can unbalance the car and cause a load peak, this load peak means that the tyre may have gone past its grip limit before you've had a chance to act or react. If a tyre has gone beyond its limit, getting it to grip again is nearly impossible.
I would first look to set my Initial, I will take a few laps on its stock setting to see how it feels. I'm ignoring the braking and accel for the minute as they are less dominant settings. I'm trying to feel how well the car rotates when off the throttle, if it is stable or understeers then I will lower the number, if I feel it is rotating too easily and becoming unstable then I will increase the Initial.
Once that is set, that sets my baseline figure for Accel/Decel, if you set anything below the initial number then it will either not do anything or cause odd characteristics. Basically if my initial is set to 12, my accel/decel have to be 12 or above.
In order to reduce peaks, I want my LSD settings to be as close as possible so the wheel speeds are constant and not constantly changing every time I make an input.

Next consideration is suspension, here I am looking to dampen the forces of acceleration as much as possible in order to make sure the rear wheels stay pushed into the ground when I get on the gas. The suspensions job is to lessen the load transferred to the tyres, when accelerating the car squats at the back and extends at the front.
In order to keep the car squatting and pushing the rear tyres into the ground I would aim to make my rear springs a little softer and my dampers will need to be set up with a low compression and a high extension. These settings will allow the car to squat (compression) and prevent it from recoiling (extension) and transferring the load back onto the front wheels.
Toe can be tricky when dealing with big power and low weight, it only really works if both wheels are doing the same thing. It works by opposing forces equally to make the car travel in a straight line, if one wheel loses grip then it stops opposing the other one and can aid unwanted rotation. The safest form in this scenario would be closer to 0.00 so the wheels are pointing forward rather than in or out which will be easier to deal with if grip is lost. You can raise the Initial on the LSD to counter the extra rotation if it is a problem during cornering.

Ballast is another thing to experiment with, you need to determine whether there is too much load on the rear wheels or not enough, both can cause problems in there own way. Too much weight at the back will make the car prone to over rotation and too little will mean that the power will just spin the wheels because they're not being pressed down on enough to maintain traction. Experiment with it, there is no right or wrong approach here.

The general problem is that tyres have limits, there is only so much force they can take before letting go. The force can come from acceleration/braking (linear force) and turning (lateral force). If you are putting a lot of lateral load in during cornering, you have very little overall grip left to accelerate with. Conversely, if you are putting a lot of linear load in under hard acceleration or braking then you have very little left for cornering. As soon as this grip limit is breached, the car will let go and continue to travel in the direction that the force is acting greatest.


I hope this helps somewhat, I can't think of anything else that may be applicable right now

 

[DolHaus]

that's not only that car which have that behavior at slow speed corner
hsv, nsx LM race car do that too
i find it totaly unrealistic , what ever you do (slowing down, throttling, accelerating slowly) it have the same reaction
i don't remember exactly but only do that under a certain speed, above it's stable

@DolHaus, by car type i mean transmission type
like in my example

There is no set point where toe is best really, it varies due to factors such as wheel base, car width, weight distribution, drivetrain, tyres and setup.
The general aim is to give the car the best possible rotation while maintaining stability and this can be achieved in a number of ways

 

[Aussie_HSV]

I have heard that the Phoenix R8 LMS is just one of those difficult cars unfortunately. Everyone says the same thing about it.
I'm not sure I'll be able to solve that one for you but I will put up some general tips just in case 👍

When dealing with power oversteer my first port of call would be the LSD, my aim is to smooth out power delivery as much as possible in order to prevent inducing load peaks. A load peak can occur when the drive wheels go from one phase to another ie. coming off the brakes and rolling the car in neutral before getting back on the gas to power out.
The differential is set to allow the powered wheels to spin at different speeds during these phases so if the speeds are too different it is like either braking the outside wheel or releasing the inside wheel. These can both cause a sudden loss or increase in grip on one wheel which can unbalance the car and cause a load peak, this load peak means that the tyre may have gone past its grip limit before you've had a chance to act or react. If a tyre has gone beyond its limit, getting it to grip again is nearly impossible.
I would first look to set my Initial, I will take a few laps on its stock setting to see how it feels. I'm ignoring the braking and accel for the minute as they are less dominant settings. I'm trying to feel how well the car rotates when off the throttle, if it is stable or understeers then I will lower the number, if I feel it is rotating too easily and becoming unstable then I will increase the Initial.
Once that is set, that sets my baseline figure for Accel/Decel, if you set anything below the initial number then it will either not do anything or cause odd characteristics. Basically if my initial is set to 12, my accel/decel have to be 12 or above.
In order to reduce peaks, I want my LSD settings to be as close as possible so the wheel speeds are constant and not constantly changing every time I make an input.

Next consideration is suspension, here I am looking to dampen the forces of acceleration as much as possible in order to make sure the rear wheels stay pushed into the ground when I get on the gas. The suspensions job is to lessen the load transferred to the tyres, when accelerating the car squats at the back and extends at the front.
In order to keep the car squatting and pushing the rear tyres into the ground I would aim to make my rear springs a little softer and my dampers will need to be set up with a low compression and a high extension. These settings will allow the car to squat (compression) and prevent it from recoiling (extension) and transferring the load back onto the front wheels.
Toe can be tricky when dealing with big power and low weight, it only really works if both wheels are doing the same thing. It works by opposing forces equally to make the car travel in a straight line, if one wheel loses grip then it stops opposing the other one and can aid unwanted rotation. The safest form in this scenario would be closer to 0.00 so the wheels are pointing forward rather than in or out which will be easier to deal with if grip is lost. You can raise the Initial on the LSD to counter the extra rotation if it is a problem during cornering.

Ballast is another thing to experiment with, you need to determine whether there is too much load on the rear wheels or not enough, both can cause problems in there own way. Too much weight at the back will make the car prone to over rotation and too little will mean that the power will just spin the wheels because they're not being pressed down on enough to maintain traction. Experiment with it, there is no right or wrong approach here.

The general problem is that tyres have limits, there is only so much force they can take before letting go. The force can come from acceleration/braking (linear force) and turning (lateral force). If you are putting a lot of lateral load in during cornering, you have very little overall grip left to accelerate with. Conversely, if you are putting a lot of linear load in under hard acceleration or braking then you have very little left for cornering. As soon as this grip limit is breached, the car will let go and continue to travel in the direction that the force is acting greatest.


I hope this helps somewhat, I can't think of anything else that may be applicable right now

Excellent stuff mate. 👍
Thanks for the detailed reply.

That description of load peaking should come in handy for me as I try to work this beast out.
Also the confirmation regarding the initial diff setting and corresponding settings after.
I thought that was how I'd seen it described, but now I'm certain I have it correct in my head.
I'll also try to put that suspension advise to good use.

Would you hate me if I said the issue seems to be largely related to entry, and not exit?
Sorry, after the big essay I should have made that a priority in my description ... my bad.
But saying that, while tuning looking for a solution I often find I've put the car into an exit power oversteer setup anyway so your answer is still of great value.

Regarding my most common problem, I would describe it as a delayed liftoff oversteer.
(Not sure if 'delayed' is the correct description, but all is fine until the very final phase to complete the corner)
I've well and truly lifted off the throttle and basically fully completed the braking phase when the back end lets go.
I would describe it akin to possibly the front end being over gripped and the back end being horribly light/loose that it almost rotates on the spot around the front wheels.
But of course reducing the grip on the front end in some backwards way to solve this issue on just one corner is completely detrimental to the rest of the lap.
And tightening the rear and/or going max. downforce or adding ballast to the rear also has little if any effect.

The car, with the majority of my setups, is quite stable during off-throttle and braking.
But whether I brake early and try to coast around the corner, brake later to finish the braking closer to the apex, or even brake later still and try to trail brake past the apex, I still always get the same result.
More often than not, even before my foot gets to the throttle the car has spun, and this is only at very slow speeds.

Would you be so kind as to add a general tip or two as to how I might go about combating this?
I think your earlier load peaking description fits quite well.
But is there anything else, or any other tricks/techniques, that I could consider?

Thanks again.
Cheers.

 

[DolHaus]

Excellent stuff mate. 👍
Thanks for the detailed reply.

That description of load peaking should come in handy for me as I try to work this beast out.
Also the confirmation regarding the initial diff setting and corresponding settings after.
I thought that was how I'd seen it described, but now I'm certain I have it correct in my head.
I'll also try to put that suspension advise to good use.

Would you hate me if I said the issue seems to be largely related to entry, and not exit?
Sorry, after the big essay I should have made that a priority in my description ... my bad.
But saying that, while tuning looking for a solution I often find I've put the car into an exit power oversteer setup anyway so your answer is still of great value.

Regarding my most common problem, I would describe it as a delayed liftoff oversteer.
(Not sure if 'delayed' is the correct description, but all is fine until the very final phase to complete the corner)
I've well and truly lifted off the throttle and basically fully completed the braking phase when the back end lets go.
I would describe it akin to possibly the front end being over gripped and the back end being horribly light/loose that it almost rotates on the spot around the front wheels.
But of course reducing the grip on the front end in some backwards way to solve this issue on just one corner is completely detrimental to the rest of the lap.
And tightening the rear and/or going max. downforce or adding ballast to the rear also has little if any effect.

The car, with the majority of my setups, is quite stable during off-throttle and braking.
But whether I brake early and try to coast around the corner, brake later to finish the braking closer to the apex, or even brake later still and try to trail brake past the apex, I still always get the same result.
More often than not, even before my foot gets to the throttle the car has spun, and this is only at very slow speeds.

Would you be so kind as to add a general tip or two as to how I might go about combating this?
I think your earlier load peaking description fits quite well.
But is there anything else, or any other tricks/techniques, that I could consider?

Thanks again.
Cheers.

Ok, if the issue is occurring on corner entry then we must think about what is happening between braking and turning in and how we can manage the forces.
When braking hard the weight is thrown forward onto the front springs, from the sounds of it you are not having any major problems there such as bottoming out because the front springs/dampers are not stiff enough (would show up as the car nodding violently when braking was at its maximum and a resultant loss of front end grip), or poorly handled weight transfer caused by overly stiff suspension (poor brake performance and a general feeling of understeer and skating).
The differential will be in its Decel setting controlling the drive wheels, if you were over rotating on the brakes then it would mean that the setting was too low and conversely if you were being forced into a straight line under braking the setting would be too high.

With this phase understood and accounted for we move onto the next phase which is when you release the brakes and roll into the corner in a neutral state. When we release the brakes the weight comes off the front springs and attempts to equalise itself. In this instance we are dealing with the dampers mostly, the front springs are recoiling and the rear springs are compressing slightly. The front to back shift can destabilise the car if not properly managed. I would raise the front extension rate first in order to dampen the transition and then perhaps lower the rear compression rate if I felt it wasn't balancing correctly. This would mean that the weight was being transferred back more gently and putting less load into the tyres. If this makes the problem worse then try it the other way around by lowering the front extension and raising the rear compression.
The differential is in a transitional state here, it goes from the Decel setting to the Initial. The settings relate to the speed differential between the wheels, lower numbers represent an open differential where the two drive wheels can spin at a vastly different speed, higher numbers represent a locked differential where the wheels are forced to spin at the same speed. With this in mind we must look at our settings and think about what happens in the LSD when we come off the brakes and into a neutral state.
Lets imagine we have a diff set at 10/15/20, the Decel is twice as high as the Initial and that means when we release the brakes and roll either wheel (usually the outside) can now rotate twice as fast as before. If the car was being held stable by not allowing the outside wheel to rotate too much faster when under braking releasing this opposing force may cause unexpected rotation when it shifts to the Initial setting. To address this I would start by deciding which original setting was more important. I would raise the Initial to 15/15/20 and see how the car felt, I would concentrate on the rotation of the car first (if you're getting excess understeer the number is too high) and observe the changes under braking. It is likely you will find that you can only raise the Initial so far without causing problems, lets imagine we settle on 12/15/20 as the highest it can go without causing problems. I would then start decreasing the braking value until I find the closest balance to prevent the wheel speed issue, probably ending up around 12/15/15. Now when the LSD switches function the wheel speeds will be more balanced and the car won't suddenly rotate as before.
The other thing to play around with is the brake balance, try experimenting here with front and rear bias at different values to slow both ends of the car at the same rate rather than having one end wanting to overtake the other. Start at 2/3 and work your way up until you find the one that gives you adequate braking force without causing the car to lock up. Don't forget to try front biased (3/2), equal (3/3) and rear bias (2/3)


I hope your answer lies somewhere in there, I think I covered most of it.
Let me know how it goes 👍

 

[Aussie_HSV]

That's awesome.
I really appreciate the time and effort you've put into those two replies.

I've already put some of your knowledge from your first reply into practice, with varying results.
It would seem to me that the 47:53 weight distribution does make the back end too heavy.
A good chunk of ballast pushed all the way forward did considerably tame the low speed spins after some additional tune adjustments.
Unfortunately, the loss of time across the full lap from the extra weight negated any time saved from being able to take that one corner with better control.
So the ballast has gone again, bar 3 kgs pushed all the way forward which changes it to 48:52.
I also found the closer settings of the diff. helped the car.
No longer running such a wide spread, and the numbers are much lower than where my last efforts had left it.
Also dropped all rear toe, and with current settings, is working much better than the last time I experimented with low toe.
All in all, definitely heading in the right direction.
Consistently running the same lap times now, and better, when comparing them to what at that stage I considered was a one-off lucky lap from a couple of days ago. 👍

So I guess I could return and persist with the ballast and try to improve the car from there.
Or, as I'm perhaps stubbornly trying to do, continue on the tuning quest without resorting to ballast and hinder the cars performance with extra weight over the full lap for the sake of just one corner.

Anyway, I'll take your extra advise away with me now and continue to try and improve this tune.
Not going to let this thing beat me.
More than happy to keep you informed of my progress. 👍

Thanks again.

 

[KING OF SKULLS]

Hi DolHaus,
i also want to say thank you for your guide. There is soo much to learn from this thread. 👍

One question, is there any chance to get a detailed guide for the transmission setup?
I think this issue is missing, since it is pretty important for a good tune.

I tune my transmission not in a technical way and it seems there's room for improvement. Maybe you can explain what is important in setting up the correct gear ratios and how it has an affect on the handling of a car.
I know that shorter gears brings accelaration and a longer gear box top speed, but aside of that it seems that it affect the handling also.

Cheers

 

[sgr]

So Ive been recently experimenting with torque on the latest seasonal. The xbow on ascari. I max out all the settings and limited the engine to 60 percent to get the pp. I thought since the huge gains in torque to less loss in hp i would get quicker lap times. Not the case. The car was to much for corners and the ghost would catch up in the straights. I thought sense ascari doesnt have a long straight torque would matter. I was wrong. When does torque matter and how much hp is lost to put gain in torque? I know i shoulda tuned suspension better to accomidate the snap torque gives outta corners but it seems hp always wins in getting better times. Any feedback on torque and hp guide lines working together is appreciated. like the suspension guidelines. I read the torque thread but was confusing.

 

[Lionheart2113]

So Ive been recently experimenting with torque on the latest seasonal. The xbow on ascari. I max out all the settings and limited the engine to 60 percent to get the pp. I thought since the huge gains in torque to less loss in hp i would get quicker lap times. Not the case. The car was to much for corners and the ghost would catch up in the straights. I thought sense ascari doesnt have a long straight torque would matter. I was wrong. When does torque matter and how much hp is lost to put gain in torque? I know i shoulda tuned suspension better to accomidate the snap torque gives outta corners but it seems hp always wins in getting better times. Any feedback on torque and hp guide lines working together is appreciated. like the suspension guidelines. I read the torque thread but was confusing.

Edit:
Reply removed

Sorry @DolHaus I just realized this was your tuning thread and not the physics one. Quick glance and only saw the 1.09, it is not my intention to step on another tuners thread/toes.

 

[sgr]

I'll admit the torque thread is confusing, but can be very informative. It will explain that even though you put on all the bells and whistles for the most torque, when you dropped the power limiter so much to reach the required pp, you started taking away torque. I would try putting on parts and checking the torque curve along with rpm gains. You are right about torque, it is very important, but it's not only the value (higher #) that matters, it's also the curve....or lack of. The less curve (flatter line from left to right) the better the torque will be throughout your RPMs.

So flat line torque curve to rising hp curve and work from there? I posted in torque thread too. the last post was good there. thanks for reply.