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is there a cure for throttle-off oversteer?

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Old 05-05-2003 | 08:31 AM
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Default is there a cure for throttle-off oversteer?


at my last autocross, in giants stadium parking lot (pretty slick), i got lots of this oversteer when i was very hard on the brake, going into a turn. all the weight goes up front, the rear becomes very light, and the backend rotates around. i try to get my braking done in a straight line, but you can't always do that in autocross. usually, the backend will go in the direction that i want, but once it went too far and the car got out of shape.

i have a stock torque arm, but koni's, LCA's and kumho v700's. the track was pretty fast where i was able to use my power. i usually compare myself to these two SCCA national participants (mike johnson and diane Lapusnak) and they usually beat me between one to two seconds. but this event i was like 1-2 seconds in front of them. they said their tires were shot, but i was happy with the cars performance, but i would like to know how to better control this throttle-off oversteer situation.
Old 05-05-2003 | 11:35 AM
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Default Re: is there a cure for throttle-off oversteer?

I'm fighting massive amounts of rear brake hop on the autocross course right now. If I trailbrake hard into a turn, the rear hops and the car rotates....HARD (I nearly spun it at the last event). I am looking into a torque arm (just because....for strength) and going to use less aggressive rear pads next time out to cure that.

As for the off throttle over steer, I try to feather it through turns to avoid dragging the rear wheels and rototing the car. Usually, a little throttle will plant the rear and keep it from getting too far out of shape (but it may push). I have experimented with slowing more for the tight stuff and it seem to work as well (and be easier on parts), but I need another event or so to verify this. Just my thoughts....GOod luck!
Old 05-05-2003 | 12:12 PM
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Default Re: is there a cure for throttle-off oversteer?

So less rear brakes is good? Im confused.

I was planning on autoxing my 94 this summer but i was worried about my rear drum brakes. I have the ls1 upgrade up front but havn't done anything with the rears. Could this be a good thing?
Old 05-05-2003 | 04:24 PM
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Default Re: is there a cure for throttle-off oversteer?

thanx trackbird. if i gave it some gas, it spun more. i need more tracktime with this situation to figure it out.

kevan, trackbird said less powerful rear brakes may be good to cure his massive amounts of rear brake hop. you shouldn't be experiencing any rear wheel brake/axle hop with your car.
Old 05-05-2003 | 04:57 PM
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Default Re: is there a cure for throttle-off oversteer?

Just a few things to try...

On the oversteer.. turn down the rear rebound on the shocks, until it goes away, then turn it up so you can induce it, but it doesn't come when you don't want it. Less aggressive rear pads will also help. I use stock rears.

On the brake hop. I've been fighting that since day 1. I have all the parts everyone says will get rid of it (torque arm, lca's, brackets, springs, etc..), and still get it in certain situations. What has worked best for me is turning up the rear rebound (which gives more oversteer.. gotta find the fine line in there), and also be smoother going into the brakes, then after they've bitten initially, go harder into the brakes.

Hope that helps.
Old 05-05-2003 | 05:02 PM
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Default Re: is there a cure for throttle-off oversteer?

I'm running very aggressive Carbotech Panther XP pads (they are a race compound pad, though I do run them on the street) and when running on race tires, I am getting an unbelieveable amount of brake hop (not unbelieveable to anyone who has the same problem....). By going back to my stock pads (or a street compound hawk or carbotech) I can "adjust" the amount of rear braking I am getting and try to cure the problem (by making the rear brakes less effective). I've talked to a few others who have suggested a more aggressive front pad (they switch the stock pads for race pads only on the front, since I already have the pads on all 4 corners, I'll just remove 2) and advised me that it has worked for them.

When I said "add a little gas", I meant just enough that the engine was not trying to slow the car. When the engine tries to slow the rear tires, it will transfer some weight to the front. On top of that it will be like dragging the emergency brake slightly. If you are familiar with the term "traction circle" (where you can either accelerate at full power, turn at full power or do a reduced combination of the 2, but not at a "full" amount), it will help explain your power off oversteer. Anyway....I hope that helps (at least a little). Good luck!



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