Sway bars
Thread Starter
Instructor
Joined: Oct 2002
Posts: 111
Likes: 1
From: Lake Arrowhead, Ca
Sway bars
I have a 1970 911T that I bought with the intention of using it 80% Track, 20% street. This week end was my first time on a non-autocross Track (1.8mi track at Willow Springs). I found that on hard cornering the inside front tire was lifting on the pavement and I was experiencing extreme understeer. I Looked under the car and found what I believe to be the stock Sway bar on the front and no sway bar on the rear. I've got to get this problem taken care of soon. As far as I know the car is basically stock, I have installed 911s brakes on the front and rear (replaced the stock struts and shocks with Bilstiens to facilitate the brake modifications. I have Don Kravig building a 2.9liter motor from a 2.4 case and a 915 trans for me that will be installed next week. I am really new to this and want to know what I can do to remedy this problem. I thought I should put a larger than stock sway bar on the rear end. and measure the sway bar up front to confirm that it is indeed a stock unit. am I going down the right path to solve this problem? If the front Sway bar is larger than stock, It seems logical that I might want to reduce the size to reduce the front rigidity. Any input on this will be greatly appreciated
Thanks.
Thanks.
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Joined: Jan 2002
Posts: 63
Likes: 0
From: Denver
These early cars seem to be more suseceptable to this for some reason. You are moving in the right direction. It sounds like you are spending some money on the drivetrain and you should also put a little into the suspension. As you suggest you need to soften the front relative to the rear to #1 eliminate the push and #2 keep the wheel down. But overall the suspension is too soft anyway. You really need to move up to aftermarket adjustable sway bars front and rear. Then you can get the car setup so it is neutral handling in the corners. Set the front and rear bar on full soft then tighten (move closer to the center of the bar) the rear bar until it starts to oversteer, then loosen it up just a little. This should keep you wheel closer to the ground if it does not eliminate the problem.
The next step is torsion bars. In addition to limiting body roll the rear torsion bars will minimize rear squat as you accelerate out of a corner. Rear squat is part of you problem also. The whole front end is lifting more than it should as you accelerate. 22 & 28 mm if you want to drive it on the street (it will still be very stiff) or 23 & 30mm if you want the best race setup.
The next step is torsion bars. In addition to limiting body roll the rear torsion bars will minimize rear squat as you accelerate out of a corner. Rear squat is part of you problem also. The whole front end is lifting more than it should as you accelerate. 22 & 28 mm if you want to drive it on the street (it will still be very stiff) or 23 & 30mm if you want the best race setup.
Thread Starter
Instructor
Joined: Oct 2002
Posts: 111
Likes: 1
From: Lake Arrowhead, Ca
Dave: Thanks for the info. Since you responded, I've done some add'l reasurch on sway bars. All the people I spoke with pretty much agreed that I should go with 22mm Bars front and rear. Checked out TRG, Smart, and Weltmeister. Big difference in price! Weltmeister bars are the least expensive. Both the TRG and Smart bars appear to have better adjustment markings and therefore easier to keep adjustments uniform Side to Side. Am I right about this? The Weltmeisters about 2/3 the price of the others. Are they a great value or are the TRG's or Smart Sway bars clearly better? (do you have a preference?) As for your comments about torsion bars, I plan to replace the torsion bars front and rear after I install the sway bars. Since I will need alignment work with torsion bars, I am planning to have Spinldes raised to lower the car at the same time. Is there any thing wrong with my logic on this priority? I've heard that racers go about alignment differently than a standard alignment to optimize tire wear. Is this accurate? If so, what is done differently when aligning for track performance?
