robrob

How would it "make the situation worse"?

The inside rear tire is being lifted by the rear anti-sway bar. As the body leans in a turn the outside suspension is compressed which moves the anti-sway bar end link up. The suspension on the inside of the turn extends but the sway bar end link moves up to lift the lower a-arm to reduce extension and reduce body roll.

On the S2000 the front outside suspension compresses more than the rear which keeps the inside front in contact with the track but allows the inside rear to lift--if the front and rear suspension compressed equally then both inside wheels would remain in contact with the track until they both lifted.

Drive around in a circle faster and faster with the rear bar disconnected and the inside rear wheel won't lift. I ran this way for over a year and never had a problem with lift until I reconnected it.

Stiffer springs = less body roll = less anti-roll bar lift.

I'm running 628 front and 571 rear springs and inside wheel lift is a huge problem with the stock rear anti-sway bar connected. That's why I gave in and bought a clutch type LSD.

Gilly_S2KFreak

I got to follow this:



for about 2 miles in stop and go city traffic today. it was lovely to follow that rear end around for about a half an hour

Gilly_S2KFreak

er... that was not supposed to go into this thread apparently my computer doesn't want to click the thread that i click... sigh oh well.


still cool hehe

FF2Skip

FTR, I ran 650/550 with Gendron bar up front almost full stiff, stock rear bar, and OEM diff. Inside wheel lift was a problem. You can hear the change in exhaust note when it occurred.

Budman05

Rob - you have several cameras you can use to see what is happening. If you can record/mix that dual view you posted, you can certainly record wheel behavior.

gfacter

VIR on Speed TV now Sunday 1-3 pm.

lots of action

Budman05

This ^^^^^^

jfo

Rob,

I think you are assuming many things are constant when they are not.

I also think the rear bar--no matter how thick--will NOT be able to compress a corner of the car by itself. In effect "lifting" up the unloaded corner, the problem is the unloaded spring doesn't have enough length and the shock doesn't have enough travel to keep that wheel on the ground. I could be wrong on that but I think the reason some people get rid of the rear bar is to eliminate any forces that could hinder the unloaded tire from staying on the ground. The unloaded tire will droop as far as possible without a sway bar connected and even if there isn't a lot of force pushing the tire onto the track at least it won't be in the air spinning. If the bar is removed the coil over spring has nothing to reduce its spring rate. It doesn't cure the problem I completely agree but it does mask it a little. Running without a rear bar might also make the car a little more forgiving. I run without a rear bar.

Speaking of droop I think where Pete is coming from is a general statement from knowledge from multiple different cars and road setups vs. track setups. When anyone puts on higher spring rate springs they are usually lower becasue if not the car would sit higher than stock. That is fine when everything is loaded but when the suspension goes to droop the higher rate spring will only push down on that tire until maximum extension which is likely less than stock length. The tire won't have any force pushing down and that tire will start spinning. I would agree with his statement in general because of the length of the spring changing.

9 competitors now in H1 at Hyperfest. How about you join? You can run any tire you want.

robrob

The sway bar isn't acting alone, the body lean helps raise the wheel. Also, all the anti-sway bar has to do is overcome the pressure of the keeper spring to lift the wheel in a corner.

I have short stiff springs but the KW V3s have a stock length stroke, that's why they use keeper springs and also why when you jack up a car all the tires droop to normal stock length.

I could see if you have your rear shocks' rebound set very stuff it could slow the shock extension enough to get a little inside wheel spin when running without a rear sway bar, but I never encountered it when I ran without a rear sway bar. Do you get inside rear wheel lift without a rear sway bar? I used to get inside front wheel lift when I ran without a rear sway bar. The Porsche Club guys told me I was lifting it completely off the ground every lap coming around the last turn leading onto the Jefferson Circuit's front straight.

I think where you guys are coming from is that fast guys get inside rear wheel lift, and fast guys have stiff springs. My proposition is that my inside rear wheel lift would be worse if I simply changed to softer (and longer) springs. I would have much more body roll which would put much more force on the rear sway bar's inside link which is what keeps the suspension from extending and putting the tire on the ground.

I'd love to go race but have a medical condition that won't allow it.

jfo

I'm thinking you are comparing how the car used to act when you used to drive it slower to now when you are driving it harder. I would say if you go back to whatever setup you had a year ago you will get the unloaded side of the car to lift. The setup from 2 years ago---lift. Hard springs soft springs rear bar or no rear bar---the wheel will lift.

Actually I believe the wheel does not lift. Said another way--the swaybar is not lifting the wheel. The car leans so much that the shock is at full droop and can no longer hit the pavement---that is the point in which you feel the tire off the ground. As Lou has suggested, put a camera in there and check it out.

Think of a Baja race truck with 2 feet of travel. Much softer springs and much more lean---you would never pick up the inside wheel. The truck might not corner as fast and it would lean like all get out---but never lift a wheel.

I definitely would get the inside wheel off the ground now. I didn't notice it in HPDE or even for a while racing but now I definitley do. I had it with and without a rear bar, PIC shocks and whatever spring rate they gave me, Tein 550# all around, KW and 457# all around, front bar CT set at medium or full stiff, and whatever bar is on the enduro car. I changed to a limited slip in my car years ago. Scot's car had the stock diff and I drove it noticed it right away, Erik noticed it, Rene noticed it, now there is a LSD in there too.

It is only on a few corners on a few tracks that it is noticable and it is only when the car is pushed way beyond what should be done in HPDE.

Your proposition assumes that you will be driving the same. You are not, you will be driving harder. I say you will have lift with whatever setup you go with. The setups will determine how fast you are--you will get the inside tire off the ground with all of them.


Get your ass to a Hospital, get fixored, and come race asap.