generic tuning Q. mid corner oversteer

[xeronima]

Hi guys

BLUF: how do you counter off brake mid corner oversteer?



I've been googleing with out any luck.

With a few cars I've been tuning I end up with a similar challenge. Right now in running the Mclaren 12c gt3 on ps4 with a wheel.

I tend to setup all my cars for a bit of 'throttle lift off oversteer' so I'm running with a bit of slow rear rebound.

How ever. I often end up with a car that will oversteer when I'm getting of the brake after corner entry. The rear end is stable on breaking. Right up to the point where I'm completely off the breaking. Then the rear start to slide.

I can't get my head around what's causing this. The weight should be transitioning from front to center. And the rear end should be moving downwards.

- tire temperature is between 75-90 Celsius.
- neutral to slight on power oversteer on corner exit.
- relative hard damper settings on 'slow bump'
- relative low arb settings.

I'm running with 'real assists' so ABS will mostly be on. I usually run with a 55-60% front brake bias.

So if any one has any suggestions on how I can address this it'd be absolutely great.

Cheers

 

[Blood*Specter]

Hi guys

BLUF: how do you counter off brake mid corner oversteer?



I've been googleing with out any luck.

With a few cars I've been tuning I end up with a similar challenge. Right now in running the Mclaren 12c gt3 on ps4 with a wheel.

I tend to setup all my cars for a bit of 'throttle lift off oversteer' so I'm running with a bit of slow rear rebound.

How ever. I often end up with a car that will oversteer when I'm getting of the brake after corner entry. The rear end is stable on breaking. Right up to the point where I'm completely off the breaking. Then the rear start to slide.

I can't get my head around what's causing this. The weight should be transitioning from front to center. And the rear end should be moving downwards.

- tire temperature is between 75-90 Celsius.
- neutral to slight on power oversteer on corner exit.
- relative hard damper settings on 'slow bump'
- relative low arb settings.

I'm running with 'real assists' so ABS will mostly be on. I usually run with a 55-60% front brake bias.

So if any one has any suggestions on how I can address this it'd be absolutely great.

Cheers

I would set all differential settings to zero. Set rear camber to -0.5 and rear toe to 0.0.
Then set rear differential pre-load to 20. Test and adjust the remaining differential settings.
Just my 2 cents. Hope it helps you.

 

[xeronima]

I would set all differential settings to zero. Set rear camber to -0.5 and rear toe to 0.0.
Then set rear differential pre-load to 20. Test and adjust the remaining differential settings.
Just my 2 cents. Hope it helps you.

I can't say that I understand why setting the differential to zero helped. And it did. Thank you @Blood*Specter .

Would you mind explaining why this works?

I was expecting that the car would start oversteering already during braking. But it didn't.

I'm not done tweaking the car for Silverstone yet. The nose still makes some funny dips when turning.

 

[Blood*Specter]

Too high limited slip deceleration (differential) and Limited slip preload make the car snaky in corners. They are attempting to control wheel spin with the throttle. If you have to stop hard, the car should remain controlled and not lock up the brakes. If that happens, increase limited slip deceleration.

Too much camber at rear wheel and too much toe in destroy balance in turns. Adjust in small increments up or down until the rear end behaves for you. Adjust camber first, then toe last.
When off the throttle the car should keep going without the rear end jumping out.

I just like to set the car as natural as I can get it, then feel what the adjustments do.

Start out with all spring rates and sway bars at the minimum setting.
Not sure what car you are tuning, but at Silverstone you need low and stiff. But there are some bumps and low points.
So slowly increase spring rate and ride height until you can get over the low points without spinning out or scraping.

For your front end, take bump stop down to zero on all wheels. Get the car as low as you can without bottoming out.
Then tighten the front sway bar and spring rates in small increments until it feels good to you in the turns.

You want the car stiff. But not so stiff as to bounce harshly over curbs and random bumps in the track.
Also look at "Fast Rebound" settings. Stiffen the front and soften the rear until the car feels smooth going over curbs.

I hope I have helped you. Good luck!