Sway bar experiment = suspension epiphany
 

The backstory: I've been fighting a bad case of understeer on the track. It got particularly worse after I went to larger (23/31) torsion bars and the Big Wing. I was able to dial it out in small increments, but it was still pretty bad. Tyson thought my car had a limited slip, it pushed so much. At Thunderhill last weekend, I almost ran straight off at the end of turn 2; when I'd mash the gas, the car headed straight for the weeds!

I had the front bar set full-soft, the rear full-hard, and that made things tolerable, but it was still out of control. Tire pressures didn't seem to be helping any more.

Then I had an idea. You see, I have TRG sway bars, and I had the "A" bar in the rear, and the "B" bar in the front. This was the setup the guys @ TRG suggested when I bought the bars 4 or 5 years ago, and I never questioned it. It was time to question it. It turns out that the A bar is the softer of the two, so my logic was if I'm maxed out on adjustment, I should switch the bars and start over. I didn't want to buy new bars, and seeing as how I couldn't get a hold of TRG, I wouldn't be able to get them for love or money anyway, I would have to make do. Wed night, Serge944 came over and helped me swap them. I had to modify the rear bar by cutting off 1/2" on each end and dressing it out, but other than that the switch was pretty straightforward.

The difference in handling was phenomenal. For the first time since I've had the 3.6L, I can actually throttle-steer it at will. I thought I was throttle steering it before, but now I can make this baby dance. I still get a little bit of push at higher speeds, but it is very manageable. In slow to mid-speed turns, I can drift the car at will and stop the drift with a touch of the wheel. It's amazing. I'm kinda bummed that I drove it bass-ackwards for so long :(

I knew there was something magical going on when I handed the guy in the GT-2 with 25k in mods his ass, and now he wants to buy my car. Yeah, it was that good. Luckily for me, Watts, Olsen, Schmidt and Stefanowicz weren't at Thunderhill today to put me in check :)

In one of the afternoon sessions, I really started to try and hang it out there, trying to counter another GT-2's HP advantage with my newfound cornering 'prowess' (I have to qualify it, because I don't think it's really mine yet). It was all I could do to keep the car on the track: braking very late and very light into 1, running 2 in 4th, only dropping to 3rd for turn 3, running over 5 hard in 3rd, and then 4th all the way to 10 - I was thrashing my poor car. I honestly need to put it on the lift to make sure I haven't broken anything. I have a reputation for being too cautious and conservative, but I let it all hang out just this once. Like the computer nerd who happens upon the drunk horny supermodel at closing time, I honestly question whether or not I can repeat the performance in the future, but right now I'm so amped up I can hardly type straight.

The stars happened to line up just right for me this one time.

Gentlemen, I present the fruits of my labors:

http://rennlight.com/gallery/image/5000196a.JPG

I should just sell the car and take up needlepoint or shuffleboard; I think I'm at the top of my game.

Damn Thom, that is a hell of an improvement. Wasn't your best time like 2:07 before?

This was running T5?

Tom

Nice catch! Very nice description. Now you've got a car you are confident with. I see even better lap times in your future.

Diz-amn. That's good, whether its with the bypass or without.

widebody,
What kind of lap times do Watts, Olsen, Schmidt and Stefanowicz post at Thunderhill?

So you loosened your rear sway settings and stiffened your front and now you can throttle steer easier? Doesnt this go against the common (discussed on this board repeatedly) theory that loosening the rear adds traction and stiffening the front will cause more push? I'm even more confused now. What is going on here?

From this thread Tyson ran a high 2:07, Jack was in the 2:08's. Stefanowicz runs in the 1:49-50 range.

Tom

Re: Sway bar experiment = suspension epiphany
 

Great line, Thom. That's going over to the OT "Quote of the day." Congratulations on your education, and thanks for sharing. :)

I thought he said he swapped the bars, not the settings. From my reading of the original post, he had a bigger bar in the front, so he swapped it to the rear and now has the balance he couldn't achieve by adjustment alone.

TT

Wow. It never would have occurred to me to swap the bars. It goes against all common "knowledge."

Very impressive (almost unheard-of) improvement. Congratulations.

Sorry I'm late to the discussion; this is the latest I've slept-in in years!

Yes, I swapped the bars - I put the softer bar in the front.

Now I wonder if I should go ahead with bigger torsion bars in the rear as Tyson had suggested.

What tires are you running Thom?

Tom

V700's, 245/45-16 and 315/35-17

Well, it gets even more interesting: I pulled the RF wheel off to check everything out (pads, etc) and the sway bar arm on that side had fallen off. So essentially I was running without a front sway bar...

Hmmm, fun isn't it?!? :) get that sucker hooked up and keep us posted!

Jeff

Thom,

Congrats!! That's fantastic news. Wonderful to go from fighting the car to dancing with it.

Cheers,

Dean

Excellent thread, Thom.

It really begs the question of whether most DIY suspension mods are for driver satisfaction (feels better/tighter) or for better performing suspension.

Thom I dont know if your running rebound adjustable shocks, but they will help in mid corner, Kevin

Shocks are my next order of business.

I'm still debating whether or not to go to larger rear torsion bars. When I nail that down, I have a spare set of shox I can send out to be re-valved. Then I'll really a platform on which I can produce consistent results.

Thom - are there differences in the "A" and "B" bar sizes?

But more importantly, do you think the handling improvements are now sort of a moot point since the front sway bar became detached?

Interesting: a long time ago, I read a Road and Track article about a German team racing a Scirocco without sway bars. They claimed the car handled much better; that the lean made the car more compliant with the variations on the track.