Flat Top

I have recently puchased a 2.7 RS (Copy of) as a pure track car. Please help me with the following:

1) In second gear corners the inside front wheel tends to lift off the ground. In my book this indicates that the front and rear roll bars are set to hard! Am I correct and should I worry about the wheel lifting. I would like to have all four wheels on the ground for the maximum amount of tyre in contact with the ground.

2) Currently I am running -3 deg camber on the front and -2 deg on the rear. I also have 5 mm toe out in the front. Where should I be going with toe at the rear?

PT

Have you corner balanced the car? That will help to reduce lifting of wheels.

For toe, I believe you really don't want toe out in the front. I'd also even suggest a small toe in in the back to stabilize it.

Howard

I see this problem at every track event. The reason your inside wheel lifts is because your sway bars are not properly matched with your torsion bars.If you soften the bars you will encounter too much body roll,so my suggestion is to go with larger torsion bars, or springs if you are running coil-overs. Since your car is a pure track car the upgrade to a stiff suspension will make for a much better handling car, most guys in the club run 23mm front and 31mm rear or with coil-overs 650# rear and 400 front.
Hope this helps !

Greg Fishman

Agree with PT in re: to toe out. Your car is probably a real handful isn't it? I know I had some toe out in my car and I could hardly keep it from hooking on me. Went to about 3mm of toe in front and rear and everything was good.

George A

Hi guys,

I've always been told that all properly set up 911 lift one of the front wheels (slightly) in slow and tight corners under acceleration. Again, what I hear is “That’s the nature of the beast”. Have you ever seen a front wheel drive car (i.e., VW GTI) lift a rear wheel off the ground while cornering? I guess the same theory applies, except in reverse.

Now, if you guys have a different theory (or facts), I would really like to hear it. My car tend to lift (again, ever so slightly) the inside wheel. I am running 450f/650r # springs with 23mm and 25mm sway bars on a 993 C2. Front bar is set to full stiff while the rear bar is at full soft. The car to me feels like it’s slightly loose (oversteer), but then again I’m fairly new to all of this (only car I’ve driven on a track). I know the alignment plays a major factor in all of this, so I guess it’s hard to separate the two.

Finally, sorry for ramble, do I set the stiffness of the bars so the inside wheel does not lift and then get it aligned to adjust for any over/under steer?

George

Alan Herod

Flat Top,
It sounds like your car was set up for autocross (or dirt track). It should turn in like crazy with all that toe-out and negative camber on front.

Howard

I run 1/16 " toe out on short tracks with lots of tight turns to help turn the car, and on the high speed tracks 1/16" toe in to eliminate shimmy at high speed. The rear on my car is set to 3/32" toe in and never changes. I don't believe your alignment settings have any relationship with wheel lift. On low speed hairpin turns the left rear springs compress and the right front unweights under acceleration. My car weighs 2300# with as stated earlier 400# springs front and 650# rear with 25.4mm sway bars front and rear. On cars similar to Greg's the norm for a track only car is 800 rear and 600# front according to the hard core racers some as high as 1100 # rear and 700# front, but it of course depends on the weight of the car. JMHO.
My buddy was running stock torsion bars on his 73 911 T with adjustable sway bars and the right front wheel was lifting 3", it was great for photos! LOL Then he realized he was giving up 25 % of the available traction, new bars, wheel lift gone.
Good luck!