Bryan Watts

Of course that would depend on what size bar he's running and a lot of other things. But agreed that in this situation, a soft front bar is causing more harm than good. With a 50 mm hollow front bar, running full soft might be the answer.

Can't underestimate the importance of controlling roll on these front MacPherson struts. Lowering, while ultimately a good thing, actually increases the tendency towards roll on the front of the car due to the roll center dropping quicker than the COG. It's the opposite of what you're taught.

And as you go lower, you often get into a less optimal portion of the camber curve as well. Lots of spring, lots of bar, and lots of static camber is often the answer to producing grip on a MacPherson strut front suspension.

Astroman

Why is it that I know your toe settings and you don't??!!

Chris has zero front toe, and 1/16" rear toe in.

Interesting comments about actually tightnening the front sway to increase grip/reduce oversteer. I only have -1.9 up front after a ton of work... It's pitiful. I absolutely can't believe that people can get anywhere near -3.0 and still be legal.

kurt M

All this talk about ARBs and no one has mentioned increasing spring rate rather than ARB? Just a shade tree hack here but I consider ARBs a tuning device not a control device. Is it not best to control body roll via spring rate? Using the ARBs to compensate for lack of spring rate leads to other complications.

crank the towers in using a strut brace and shave the hood.

Gary R.

Isn't that a bump steer kit to help with tie rod angle on a lowered car?

Bryan Watts

Probably because the thread is called "sway bars"?

Gary R.

And that in torsion bar cars you cant increase spring rate (beyond what is on Chris's car) and stay in PCA stock classes..

dbryant61

Gary,

Why can't he go with a thicker front t-bar? I have heard that 26mm will fit in the A-arms. Thanks for the correction on scrut at the Glen. Aren't rumors great?

Gary R.

Not sure what fits Don, we mostly run Smart Racing through the body bars up here..

Chris M.

Thanks for the tips. I will try them out in a few weeks at Road Atlanta.

Don is talking about 26mm torsion bars. I've heard of 24s, but they weren't available at the time I was doing my suspension. The bigger the better, according to Larry Herman, who will hopefully chime in here at some point, and tell us how soft even the stiffest torsion bars are in terms of actual spring rate. I forget the numbers, but he has them.

Thanks buddy. I'm still waiting for the mystery of -3 degrees to be answered....can cranking on the strut brace really make up the difference?


Don- sorry for the hijack.

Gary R.

Yep, I got all flummoxed up.. I ran 24/33 in my 930 but run 23/31 now.. don't really think I need more spring for this car.

Larry Herman

Chris, IIRC the 23 mm fronts equaled a coil spring rate of about 275 lbs/in and 31 mm rears equaled about 375. I felt that this was fairly close, but have 2 sources for you to check: Pelicanparts Forum and Rennlist Forum. They are not exactly the same, but do confirm that the torsion bar rates are pretty soft as compared to what you can get with coil-overs. Plus you can see yourself how much the torsion bar cars lean as compared to well-sprung C2s.

Chris M.

Thanks Larry.

sig_a

(Thanks also Wil Ferch)

Gary R.

Call Dan Jacobs if you want to know what to run, or if you know of someones LEGAL cars that have a better record than those prepared by him I would call them.... I'll be the first to admit the only thing limiting my car is ME...