What is the best way to cure oversteer under acceleration?

[jucksmanBR]

Well, although the title is self-explanatory, what I'm triying to figure out is what would be the best way to cure oversteer at corner exit in high-powered, FR cars like the GT500 GT-R's.

Some say the best way is more positive rear toe. Some say it's by lowering rear springs, some say it's by hardening the rear...it can get really confusing sometimes...

Any Help?

 

[CyKosis1973]

It's confusing because there are so many variables that can cause such a problem, which in turn leads to many fixes.

You may have to get a bit more specific, or provide details of a specific car. There's not much more we can tell you that you can't already read in the stickies above. Which we've all had to do. The onus is on you to work out and understand for yourself what the individual elements are, how they effect a car and what it is that's causing you problems. I've kept the below, which is about as simple in terms of explanation as it gets, but it's also succinct. Along with all the other good guides on these pages, it helps me to understand where the problems are with my car and fix them (mostly)...

{Cy}

Here’s a brief guide I wrote
I haven’t had any feedback on it yet but maybe now’s the time
Would like to see what people think about it and maybe correct on a few things if needed.

Ride Height
Front
- Higher Numbers = More grip at Front / More likely to oversteer
- Lower Numbers = Less grip at Front / More likely to understeer

Rear
- Higher Numbers = More grip at rear / More likely to understeer
- Lower Numbers = Less grip at rear / More likely to oversteer

Spring Rate
Front
- Higher numbers = More grip at front / more likely to oversteer
- Lower numbers = Less grip at front / more likely to understeer

Rear
- Higher numbers = More grip at rear / more likely to understeer
- Lower numbers = Less grip at rear / more likely to oversteer

Dampers
Front Extension
- Higher Numbers = Stops the weight from shifting off of the front tyres immediately / keeps weight over the front tyres for longer when accelerating, good for FF cars / reduces understeer during corner exit
- Lower Numbers = Allows the weight to shift off of the front tyres more quickly / makes it easier for weight to shift to the rear more quickly. / reduces oversteer during corner exit

Rear Extension
- Higher Numbers = Stops the weight from shifting off of the rear tyres immediately / keeps weight over the rear tyres for longer, good for rwd cars / reduces oversteer during cornering
- Lower Numbers = Allows the weight to shift off of the rear tyres more easily / makes it easier for weight to shift to the front when decelerating / more likely to oversteer during corner entry

Front Compression
- Higher Numbers = Harder for weight to shift onto the front tyres / good for RWD cars or to reduce oversteer/increase understeer
- Lower Numbers = Easier for weight to shift onto the front tyres / good for FWD cars or to increase overseer/reduce understeer

Rear Compression
- Higher Numbers = Harder for weight to shift onto the rear tyres / good for FF cars or to reduce understeer/increase oversteer
- Lower Numbers = Easier for weight to shift onto the rear tyres / good for RWD cars or to reduce oversteer/increase understeer

Anti-Roll Bars
Front
- Higher Numbers = More Grip at rear / More likely to understeer / increases steering response
- Lower Numbers = More Grip at front / More likely to oversteer / decreases steering response

Rear
- Higher Numbers = More grip at front / More likely to oversteer / good for FF cars
- Lower numbers = More grip at rear / More likely to understeer /

Camber
Front
- Higher Numbers = Increases front grip during cornering / reduces understeer / increases tyre wear
- Lower Numbers = Less front grip during cornering / reduces understeer / less tyre wear

Rear
- Higher Numbers = Increases rear grip during cornering / reduces oversteer / increases tyre wear
- Lower Numbers = Less rear grip during cornering / reduces oversteer / less tyre wear

Toe
Front
- Higher Numbers (+) = Increases front stability / increases understeer / more steering response / increases tyre wear
- Lower Numbers (-) = Increases front turn-in / increases oversteer / less steering response / less tyre wear

Rear
- Higher Numbers (+) = Increases rear stability / increases understeer / more traction / increases tyre wear
- Lower Numbers (-) = Decreases rear stability / increases oversteer / less traction / less tyre wear

LSD

Initial Torque
- The higher this setting is, the more easily the LSD will lock and the more responsive acceleration will be. The lower it is, the more slowly the LSD will take effect. Increasing the Initial Torque will accentuate the handling peculiarities of a vehicle's drivetrain layout. Therefore, oversteer will be increased in RWD cars and understeer will be increased in FWD cars. Although this improves traction in both cases, it will make turning more difficult. As such, initial torque adjustments should be made with the desired handling requirements in mind.

Acceleration Sensitivity
- The acceleration setting governs the effectiveness of the LSD when stepping on the accelerator and the stronger it is, the more drive power is transmitted to the wheels and the more quickly the car will be able to clear corners. However, this will also accentuate any handling peculiarities, and getting the car to point in the direction needed to exit the corner may require some skill.

Deceleration Sensitivity
- The deceleration setting governs the effectiveness of the LSD when the accelerator is released. The stronger it is, the more stable it will be upon entry into a corner while braking. This allows you to go into the turn very fast, because you can keep braking longer than you would otherwise. However, this makes turning more difficult and is only recommended for advanced drivers who are skilled at compensating for initial understeer.

 

[MrGrado]

I think the best way to cure it is more rear camber. Other than that, I suggest to ty a few things.

 

[jucksmanBR]

How much rear camber is too much? I'm usually using between 0.5 and 0.9...

 

[Ridox2JZGTE]

I have 2.8 on my Yellow Bird tune, and it helped the rear putting down traction. Here is my tune posted at DeadNutsEvenRacing club.

RUF Yellow Bird '87 Cape Ring South Tune Sports Hard

The limit may varies from car to car, maybe a several acceleration from standing start test at the Route X track will help, run several camber increasing from 0.0 to 3.0

Most of my tunes used for racing have 1.2 to 1.8 at the rear for FR cars, higher for FF, RR and MR cars, 1.8 works extremely well on Z34 Fairlady.

 

[lldantell]

thats a lot of rear camber

 

[trackripper123]

Throttle control. Try it, and if it doesn't work, then blame the tune.

 

[Lambob]

give it inside wheel spin, with a lower accel LSD, then tune it to battle understeer push. Praiano seems to tune this way lately, and I agree with the sensations, his 550pp Mercedez Academy replica, I can win most 550pp races around the 24hr Nur layout with it. Praiano, if you read this complement, it's the best 550 bar none. not so much for brute laptimes, but the consistency it provides.

 

[lldantell]

Well, although the title is self-explanatory, what I'm triying to figure out is what would be the best way to cure oversteer at corner exit in high-powered, FR cars like the GT500 GT-R's.

Some say the best way is more positive rear toe. Some say it's by lowering rear springs, some say it's by hardening the rear...it can get really confusing sometimes...

Any Help?

I would release all of then power around a downhill fast corner or the exit of the corner.to get rid of it,raise the rear camber and toe.

 

[Adrenaline]

Give us the current setup, so we can see what's wrong, but LSD is the easiest fix.

 

[jucksmanBR]

Give us the current setup, so we can see what's wrong, but LSD is the easiest fix.

Actually, there's no specific setup. I'm trying to learn better how to tune and trying to understand how to solve oversteer...

 

[Motor City Hami]

I have 2.8 on my Yellow Bird tune, and it helped the rear putting down traction.

The limit may varies from car to car, maybe a several acceleration from standing start test at the Route X track will help, run several camber increasing from 0.0 to 3.0

Most of my tunes used for racing have 1.2 to 1.8 at the rear for FR cars, higher for FF, RR and MR cars, 1.8 works extremely well on Z34 Fairlady.

thats a lot of rear camber

Actually, I have done some camber testing for 2.0. I would like to repeat this for 2.09 physics. https://www.gtplanet.net/forum/showthread.php?p=6706322#post6706322 I have found that there is a sweet spot for most cars for grip and reduced overheated, red tires. That range for me for most cars is 2.5 to 3.2. I only use lower camber settings if I am trying to reduce grip on one end of the car. All of my 2.09 camber testing, though not as scientific as the linked test, has confirmed my findings from 2.0. Again, I do plan to retest in that more scientific method. I said it in that thread and I will say it here, show your work... post your tests and people will be more likely to believe that 1.0 is better.

Give us the current setup, so we can see what's wrong, but LSD is the easiest fix.

100% agree with Adrenaline. The LSD can make big differences so start there. My experiences have indicated that most other settings are for fine tuning. To calm oversteer on corner exit, first check to see if one of the drive tires is breaking loose first; inside wheel or outside wheel. You may have to install harder tires and jam the gas in a second gear corner to see which turns red first. If inside wheel, raise LSD Accel, if outside wheel, lower it. Go until both turn red at the same time. If you still have oversteer after this, raise LSD Initial Torque.

 

[Ridox2JZGTE]

Actually, I have done some camber testing for 2.0. I would like to repeat this for 2.09 physics. https://www.gtplanet.net/forum/showthread.php?p=6706322#post6706322 I have found that there is a sweet spot for most cars for grip and reduced overheated, red tires. That range for me for most cars is 2.5 to 3.2. I only use lower camber settings if I am trying to reduce grip on one end of the car. All of my 2.09 camber testing, though not as scientific as the linked test, has confirmed my findings from 2.0. Again, I do plan to retest in that more scientific method. I said it in that thread and I will say it here, show your work... post your tests and people will be more likely to believe that 1.0 is better.

If inside wheel, raise LSD Accel, if outside wheel, lower it. Go until both turn red at the same time. If you still have oversteer after this, raise LSD Initial Torque.

My Z33 in the picture ( Cape Ring South 1st hairpin ) have 1.8 camber at the rear and 2.8 at the front, LSD was around 6/10/5, pretty low, but even in a heated 2 wide battle on corner exits against AWD Evo, it can still put up a fight with a reasonable black tire marks Blame it to my overzealous application of throttle.

EDIT : 2000th post