S2000 Under The Hood S2000 Technical and Mechanical discussions.

RWD newbie question

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Old May 8, 2008 | 07:08 PM
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just picked up my 01 spa a week or so ago, lovin every minute of it.

i noticed on the way home from the dealer, that, while in a corner (nothing crazy, maybe 35 mph on a 55 mph highway) if i let off the gas, the car would turn in. its not a grip issue, tires dont squeal, not even pushing the car at all, and it does it at all speeds. if i get back on the gas, the car will correct to the same radius it was turning at before. it does this while turning left or right.

i had the car aligned, and that seemed to help the problem, but its still there. while car was being aligned, mechanic and i checked all joints and nothing was loose. car is really clean underneath.

called a trans/diff shop today, he said i need a diff service (fluid change), but he was a bit mis informed on the type of lsd our cars have. said it was a clutch type after i specifcally told him otherwise.

im just a bit worried that my lack of rwd experience plus this issue will end me up in a ditch or wrapped around a tree.

if you guys have any advice, id greatly appreciate it!

thanks!
james

PS
tires are fine, 1st thing i checked!
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Old May 8, 2008 | 07:15 PM
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thats normal
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Old May 8, 2008 | 07:27 PM
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is it normal for an ap1 or ap2 as well. i asked a couple of buddies about it and they hadnt felt it in their S's (both 04)
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Old May 8, 2008 | 10:11 PM
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The AP1's oversteer more, though I didn't realize by that much. You usually don't want to be lifting off the gas in a turn anyway with RWD...tho i didn't think it'd factor at 35 mph...that's interesting. I want to test drive someone's ap1 now.
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Old May 9, 2008 | 02:17 AM
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You have a 2001 AP1. these are the most sensitive to changes in weight distribution (getting on or off the gass).

AP1's have bump steer and changes in weight distribution make the car steer into the corner when letting off the gas. this is very scary at first but u get used to it and learn to feather your inputs to the car.
the bump steer was incorporated to make the car more responsive.

AP2's do not have bump steer incorporated in the suspention and do not have this effect.
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Old May 9, 2008 | 02:29 AM
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my ap2 does it but its not that ap1's have it and ap2's dont ALL cars do this the suspension may contribute but its just a matter of weight transfer.
let off the gas, the weight will shift a little to the front loading the front tires which in turn produce more grip. this can be easliy proved with highschool physics.
hit the gas again and you are back to where you were.
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Old May 9, 2008 | 01:16 PM
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Originally Posted by shrek,May 9 2008, 05:17 AM
AP1's have bump steer and changes in weight distribution make the car steer into the corner when letting off the gas. this is very scary at first but u get used to it and learn to feather your inputs to the car.
the bump steer was incorporated to make the car more responsive.
Be aware that the roll steer (aka "bumpsteer") at the back of the AP1'a steers the BACK WHEELS into the turn as the car rolls, thereby producing either (depending on how you look at it) less oversteer, or more understeer. It DOES NOT make the car turn in more, as it's the back wheels that steer into the turn (meaning that the car actually turns in a little less, as it rolls into a turn).

This allows a stronger static oversteer bias, giving sharper initial turn-in, which is reduced as the car rolls into the turn and the back tires turn in, reducing the amount of oversteer.

99% of what has been written about the roll steer designed into the AP1 rear suspension has been wrong, starting out with incorrectly calling it "bump steer."
Bump steer happens at the front of a car, not the back, so you know when someone calls it "bump steer" they're starting out confused.
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Old May 9, 2008 | 01:20 PM
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Originally Posted by jzz30,May 9 2008, 05:29 AM
my ap2 does it but its not that ap1's have it and ap2's dont ALL cars do this the suspension may contribute but its just a matter of weight transfer.
let off the gas, the weight will shift a little to the front loading the front tires which in turn produce more grip. this can be easliy proved with highschool physics.
hit the gas again and you are back to where you were.
All cars do react to weight transfer; Some more than others. Because the S2000 has such great feedback, it's hard to miss. You can even feel the effect of a 2 pound difference in rear tire pressure on this car. Compare that to an E320, where a tire can be almost flat before you notice. Everything the S2000 does is more obvious than with *most* other cars.

Try a Merkur XR-4Ti; They have very strong turn-in on throttle lift, and go wide with throttle application, far more than the S2000. Makes for a very easy car to drive fast in the twisties.
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Old May 9, 2008 | 01:26 PM
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Mine does exactly as the OP said as well. Doesnt matter the speed or intensity of driving. I noticed it when I got the car even driving at 4/10 or so. After owning the car for a while now, I dont really feel it at all as its natural now, but Ive driven other cars since and I notice when it doesnt do it!
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Old May 9, 2008 | 03:04 PM
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thanks for the resposes guys! i do feel better knowing that its nothing "wrong" with the car. first time i felt it, i thought, oh sh$t, my diff's goin out. insert sigh of relief here_____!

i do know that lifting throttle in a turn is a no no in a rwd, but as i said, i have very little experience with rwd, been driving front drive honda's for most of my life.

i guess this is something that ill just have to get used to, and learn to drive around it for a while untill i can drive the car with more confidence.

thanks for all the help guys!

james
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