I have seen a haldex adjustment which seems like it would work well to take push out, but it was $1000+. Are aftermarket sway bars even effective on these cars? Or do they just make the handling worse.

Ohlins North American head quarters is in my home town, and my father has made good friends with their head engineer. My oldest brother and father have spent countless hours on Ohlins 7 poster shake rig testing sway bars on a 1989 Porsche 951 S. They found that the car reacted better with the stock sway bars. The after market ones performed so poorly the car would handle better with no sway bar even hooked up comparerd to the aftermarket bars! My brother is the current National Champion in 944 super cup, so were pretty confident in our research.

 

Rear sway bar replaced with 19mm bar and a good alignment gets rid of lots of understeer, but not all...Car is FWD biased, hard to get around a nose heavy car and dial out all understeer...Neutral handling is achievable, but not cheap...

 

what brand sway bar? leave the front stock? so is neutral achievable by just a sway bar?

 

These cars are actually pretty neutral at higher speeds when one cannot accelerate much thru the corner. In 4th or 5th gear at say 90 mph one does not have the power available to overtax the predominate drive wheels (front) thus they have more traction available for lateral force. (turning) In this condition the front is doing more or less the same work as the rear and the car is fairly neutral. If one starts to run out of road and lifts, the car will oversteer. If you add a larger rear bar, this CAN be a handful. So- for high speed cornering, only a bit more rear roll stiffness should be added, unless one adds front roll stiffness too, to keep the car balanced. At low speeds in 2nd or 3rd gear there is much more wheel torque available and it is easier to overtax the front wheels traction with linear acceleration. (and weight transfer to the rear) When this happens the front wheels can't turn the car. No lateral grip is available for turning. Understeer! The Haldex modification should help some as it is supposed to add rear torque earlier, but the Haldex is already capable of more or less locking front to rear so I'm not sure. A bigger rear bar will help because it will make the rear tires fight the roll and let the inside front carry more weight and thus have more traction. (You have seen FWD race cars carry one rear wheel in the air on low speed corner entry I'm sure.) Like most everything else, this is a trade off. We have to choose between high speed corner stability and low speed corner neutral handling. I choose the safety in high speed corners. It only took one spin at 90 mph to make me do so.

 

I got you on the driving styles, I also race a Porsche 944 along with my brothers, but they are rear wheel drive. What kind of sway bar do you suggest if I were to pursue better 2nd and 3rd gear handling, here in the mountains of NC I run tight turns, much like turns 7a-8a at barber, i assume your familiar with those turns living in Alabama

 

: I first tried a H&R 21mm rear bar thinking I need LOTS more rear roll stiffness. It was too much everywhere! I have a habit of trailbraking into slower corners and I would get sideways and have to countersteer. Maybe I could have relearned and adjusted to that but before I did, I had my 360 at Barber in the exit of T 10 (the second esse on the back stretch. I suffered through that one day event and went home and put the stock bar back on. After a couple more events I bought the Hotchkiss Sport front and rear tubular adjustable set. I have run them at soft front and rear and it is much like stock but a bit stiffer and with a bit less understeer. Next event I'm going to move the rear links to the middle hole and see how that is. I'm still learning. The one thing I do know is that having the rear break loose and come around while in 4th gear at full throttle is a big attention getter. Far better to alter ones low speed corner technique with a very late apex which allows late braking in a straight line, followed by an easy exit with far less lateral g's . I did Road Atlanta recently and my Instructor was a 944 driver. It was difficult for him to understand why I did some of the things I did. When the front would push out in T 7 and I would lift to plant the front tires he would call for throttle to rotate the car. Dosn't happen in a TT. On the other had, I have not seen a 944 that I could not keep up with. Yet. Have not met you of course :-)

One more thing; Lots of owners run the NewSpeed 19mm rear bar and report that it balances the car nicely retaining the stock front bar.

 

well I guess I'll just have to play around with it on the street. The H&R bar that you had might be the ticket in something rear wheel drive. Remember that loose is fast! not the spinning drifter loose though ha. But as far as the track and the 44, I have only been racing cars for three years now... I started racing karts when I was 10 and raced those for 5 years. the difference from a go kart to a car is HUGE! The whole suspension thing threw me off for my first couple of DE's. I'm sure that I am not driving my race car to its full potential but that hasn't stopped me from a few wins. I fully understand the lift to plant the tire, oh and how do you trail brake in these cars with the stupid deal that won't let you apply the break with full gas? Can you turn that off, if so please tell me i hate not being able to trail brake and build boost in turns! But i'll quit rambeling if you want to see some footage from last year check this out...
http://videos.streetfire.net/video/N...als_207746.htm

 

I did much the same thing coming out of 10 at Infineon a few years ago. Mine was more of a mechanical cause, the rear sway bar link bolt sheared on the right side. I ended up doing a 540 at about 85 plus. But thankfully I stayed in a straight line away from the walls. And, I did not soil my armor.

Since that time, I've kept pretty much the same setup. 19mm Neuspeed in the rear, the only change has been that I've added the Haldex Orange controller. I find it is actually more stable in high and low speed corners. The engine braking now working on all four wheels keeps the car more neutral and I find I can apply even more power than before in carousel corners.

 

Agreed. To get neutral and even a little oversteer bias, I've corner balanced the setup, added more rear camber and a Haldex competition controller. Now throttle steering and trail braking work predictably, whereas before the car still had a tendency to plow in the corners.

 

In my opinion, I think the TT has a lot of understeer only if you push the car beyond its limits... unlike a FWD or RWD, I find that linear braking pre-turn and then giving gas during entry breaks the back end loose nicely. For sharp cornering the car needs a 'swooping' entry with moderate gas pedal until the car can pull itself up and out of the turn. I drive mine stock, so I maybe be out of league with anyone that has track experience but for driving a stock car I have had to learn to deal with the problem in creative ways. My first suspension mod will more then likely be a rear sway bar as EVERYONE says a front with make the understeer terribly unmanageable. I'd like to try adjustable so I can learn the differences between settings. Anyway, if you haven't already, try learning the car as is for a little bit just to get a better feel how to make the car work better as is.. that way, any improvements will be exponential.

Have fun!