At track this weekend and need some advice on curing oversteer

[SpiralOut]

I'm at track this weekend and dealing with some wicked oversteer. On the gas or off the gas the back wants to come around on all slow turns.

This is my first event on real Race tires (used Continentals from Bimmerworld).
2013 ZCP/EDC with Swift spec-R springs and dinan camber plates (frist event with this setup as well).
-2.5 Camber front
-1.9 Camber rear

My car has always had more of a slight understeer so not sure what has caused it to go waaay the other way. I'm guessing either the springs changed the balance or the tires are very sensitive to pressures and I'm way off on what i ran today.

Can tire pressures help? If so what pressure should I run in these tires? Everyone i ask at the track gives me a different answer.... always depends on car and weight i guess.

[arter]

To decrease over steer, decrease rear tire pressures compared to front
and/or decrease front negative chamber. Try dropping the rears to 32-35 hot to see if that helps

You could also go softer on the rear springs.

I would also put your other tires back on, maybe the Conti's are not sticking like they should be....

[jbraslins]

If your shocks are adjustable, could try stiffening the front or softening the rear.

And obviously, don't lift mid corner maintenance throttle when in doubt.

[bigjae1976]

What you're describing is normal since you added a lot of grip to the front axle. Be smoother on the throttle.

[Raucky2000]

Sounds like you need more spring rate and damping, since you added a lot more grip.

Being smoother will obviously help too.

[Groundpilot]

If you are on used continental race tires from bimmerworld, they might be cycled out. Even if they have enough rubber left, in that case they have no more grip and you are better off using your street tires.

[Drifty//]

I agree with the comments about increasing front and/or decreasing rear pressures. To figure out which, you should look at how far to the edge the wear is happening on each, and that will give you a good indication you how each tire is infllated relative to what would give that tire optimal grip.

That aside, I wonder if the issue might be related to the toe setting. I've been told by a track veteran that insufficient rear toe in will cause the rear to step out more easily. Also, any toe out in front will probably make the front end more grabby. I'm on street tires, but I run with 0 front toe and I think 1/32" rear toe in, and my rear stays pretty well planted (when I want it to ), but one of the first things I'd do is go to 1/16" rear toe in, if I had your problem.

Other things you can do: add more rear downforce, either through a (bigger) spoiler or setting your ride height to have some rake (I have my rear 0.5" higher than front, as measured between the ground and the bottom of your car). And you could remove some front downforce, like if you have a removable front splitter.

Of course, in the short term, you can also use a higher gear on the corners giving you the most trouble.

[SpiralOut]

Thanks for advice. Will try some stuff today with pressures and maybe different EDC settings and see what happens.

[PrimeBMW]

The first thing I thought of was that the rear tires are heat cycled out or old. Next time buy from Turner as they are racing that tire on two cars currently........Bummerworld not so often. The car should be balanced unless someone gave you the wrong springs. That tire should work well at 38-40 psi hot. Faster at 40 but easier to drive at 38. Try swapping tires front to rear and hope at least the two fronts have more grip.

[SpiralOut]

Originally Posted by PrimeBMW

The first thing I thought of was that the rear tires are heat cycled out or old. Next time buy from Turner as they are racing that tire on two cars currently........Bummerworld not so often. The car should be balanced unless someone gave you the wrong springs. That tire should work well at 38-40 psi hot. Faster at 40 but easier to drive at 38. Try swapping tires front to rear and hope at least the two fronts have more grip.

I think you're right. I moved yesterdays rears to the front and today I had better grip in the rear, but had understeer which i definitely didn't have yesterday. So looks like it was the tires... those 2 must have been pretty much heat cycled out and the other 2 weren't that much better. Played around with the pressures some and was able to run my fastest lap ever there, but it was just barely faster than my R888/NT01 laps. Next time i guess I'll either try the ones from turner or i'll just buy new.

[PrimeBMW]

It can be hit or miss when buying used race tires. I had good luck with Conti scrubs from Turner but now get used Yokohama race scrubs. Most are very good but others feel like your on ice/heat cycled out from the get go.