Date: Fri, 15 Mar 1996 13:23:59 PST
From: Andrew Chan 
To: honda-perf , Ken Davis 
Subject: HP: fwd lift throttle oversteer
Message-ID: 


I find myself doing this quite a bit - it's great fun. I have a set of 
RE92s on the front at 35 psi and Nokia snows on the rear at 44... there's 
no snow outside anymore, but I've been having so much fun I'm not putting 
on the D40M2s yet. The difference in F/R traction caused by the pressures 
and tire constuction allows this behaviour - and I don't think I could do 
L-T oversteer with 4 same tires since the GS-R is dialed in for too much 
understeer - until i get my Koni adjustables, that is. I chop the 
throttle in 2nd gear right before i clip the apex of a [sharp] turn. The 
rear gently swings around like a pendulum, then a split second before i'm 
pointed in the right direction i add throttle since there is a slight 
delay in response (not like a rwd car), when the car reacts, settles inline, 
then i nail it out of the corner... too much fun. It's not the quickest 
way around the corner, but when you're having such a blast, who cares??? I 
miss driving my friend's rwd 240sx and fwd Corrado for this reason. But 
be careful not to overstep your bounds (I wouldn't try this in the wet, 
or do it to impress pedestrians ;> ) 'cause if you lose it in a fwd car, 
the rear will snap around, and recovery is (relatively) difficult.

Try it in an empty parking lot with a slight incline. Going down the 
incline and doing the turn would help the oversteer, so you can see what 
it's like without going too fast.


-Andrewski
'95 GS-R
 K&N, Razo Mag Pedals, quickly wearing snow tires
soon:
 Koni single-rebound adjustables
 H&R/Neuspeed Sport Springs
 Cold air induction
 ---> Brake Pads!!!


Ken Davis wrote :

>"lift-off oversteer". =
>I suppose it's the process of going into a turn at full throttle to the =
>point of major understeer and violently letting off the throttle. They =
>say it's supposed to break the traction of the lighter rear end and give =
>you the ability to slide the tail out like a rwd car. I've reluctantly =
>tried this, but my Bridgestones can't handle it and nothing =
>happens....anyone else try this or are willing to try this?

-Ken Davis
89 CRX Si

Date: Fri, 15 Mar 1996 15:07:41 -0500 From: SCoggin@aol.com To: honda-perf@listserv.oit.unc.edu Subject: HP Oversteer in FWD Message-ID: <960315150739_447278549@emout09.mail.aol.com>

Lift throttle oversteer can be explained in terms of acceleration and weight transfer. At the limit, if the driver lifts off the throttle, oversteer is the result. This is because weight was transfered forward, increasing front traction and decreasing rear traction. At the same time, the front end is decelerating. The advantage of FWD is the ability to 'gather the car back up' in this situation. In a FWD, oversteer is corrected by increasing throttle. This transfer weight to the rear tires which increase their traction. More importantly, this accelerates (or pulls) the front end of the car back in front of the rear end of the car. Cool, aye? Many happy slides and corrects, Scott BTW - Overly simple explanation, but one which conveys the technique (I hope) >Lift throttle oversteer can be explained in terms of acceleration and weight >transfer. At the limit, if the driver lifts off the throttle, oversteer is >the result. This is because weight was transfered forward, increasing front >traction and decreasing rear traction. At the same time, the front end is >decelerating. I think you explained LTO clearly. But I think the original question is how LTO occurs in FWD cars. One would think that a FWD would "love" to have throttle lift. At first glance, LT would seem to give the fronts the weight they need to hook up to counteract the understeer. Let's clarify some more. In a FWD, LTO needs some combination of the following : a light tail section (CRX!) stiff rear suspension (think Tokicos/Konis on ultra stiff on Race Springs) crappy rear tires (Michelins -- nuff said) tire pressures The effect of Over/Under steer is caused by the relative difference in traction at both ends of a car. So think of a FWD understeering in a turn on max throttle. When one lifts throttle, the car goes from max amount X of acceleration to 0 very very quickly. The weight of the car suddenly shifts to the front. Since the car has stopped trying to accelerate in a turn and the weight has shifted forward, the front tires on the edge of losing traction now hook up. Great! So we're no longer understeering! But what's going on at the rear? The rear has been completely unloaded from the sudden deceleration and the weight has moved to the front. The combination of a light rear weight distribution, stiff rear suspension, and tire traction prohibit the rear from regaining its traction prior to LT. So you have the front wheels with MUCH more traction than the rear. Voila, the rear will swing around. You now have oversteer in FWD. >The advantage of FWD is the ability to 'gather the car back up' in this >situation. What do you mean? >In a FWD, oversteer is corrected by increasing throttle. This transfer >weight to the rear tires which increase their traction. More importantly, >this accelerates (or pulls) the front end of the car back in front of the >rear end of the car. Cool, aye? Weight transfer remains the same regardless of drive wheels. When oversteering, throttle application will help (this applies to RWD & FWD) to correct it. The only exception is in powerful RWD cars (if you're power oversteering, throttle application IS your problem) When ordinary drivers come into turns too fast, the first instinct is to get on the brakes. This is good in a understeer scenario but very bad on a oversteer one. Hence FWD is a safer street setup for the masses. Oversteer induced by LT can also be induced by braking. That's why you never SLAM on the brakes in a turn! LTO is harder to acheive due to other factors (braking transfers much more weight than lifting throttle) In a RWD at the limit, you never want to LT or brake. In a FWD at the limit, a little LT/brake may be desirable. :D - Jeffrey How come no one talks about power understeer? I think it's pretty cool... :D