From what I found, the rear bar arm length is very limited due to the angle of the down link. It is too close to the arm so, with a setting at either end of the arm, the link was at a severe angle. Lengthening the down link lowered the arm lower than I was ever comfortable with.

I do not run Welty's on either car.

Big Dog

There is a lot that enters into adjustments, including spring choices, amount of lock up on the LSD, track particulars, driver preference, etc.

With a McPherson strut up front, roll is generally undesirable, as it leads to camber loss, a bit more in the early offset cars with the shorter a-arm. The RR's seem to need more camber, as well, so I'd be cautious about making a bar too soft. On the other hand Tarret's at full stiff in the front, can crack a steel a-arm pretty quickly if it's not carefully box welded. Tarret hardware is very nice - much better than the Welt in that way.

FWIW, I run slightly on the stiff side of mid-ways front and rear on my Tarrets as a baseline, and then adjust to the track. I have 400# front springs, and 30mm solid rear torsions. Just changing fluid in my LSD to one w/o the LSD friction modifier changes the handling balance quit a bit, I've found (by accident).

BTW, great to see the free flow of information here!

What was the nature of the change in handling when you changed the fluid in the diff and what did you change from and change to? With the suspension adjustments being as limited as they are I'm always interested in hearing about anything that may change the handling characteristics.

On a clutch type diff,like the OEM LSD, removing the friction modifier will increase the amount of lock up in the diff. This resists turning (the extreme eaxmple would be a locked diff or spool), and relatively more understeer. Pro teams will fine tune handling with adding in little bits of friction modifier. In our cars, the OEM LSD isn't strong enough to make a dramatic difference. They syncros sure liked leaving out the friction modifier - trans shifted a bit better/smoother. Syncos need friction to work.

Thanks Eric. I run an OEM diff and that's good information. What fluid are you running?

I had been using Redline 75W90.

Since Royal Purple got me this nice suit I decided to try that once, too. Seems comparable.

Throwing everything off a bit, though, was that I found out my RR shock was mostly blown at Nationals. As part of tech we did a shock dyno. The report I got back was that everyone passed, but to tell the #80 guy that his RR shock is blown. Damn, that's me! This may have confounded any handling changes that I attributed to fuild changes if it had been getting worse for for some time.

spec944#74 wrote:


I had been using Redline 75W90.

Since Royal Purple got me this nice suit I decided to try that once, too. Seems comparable.


Throwing everything off a bit, though, was that I found out my RR shock was mostly blown at Nationals. As part of tech, we did a shock dyno. The report I got back was that everyone passed, but to tell the #80 guy that his RR shock is blown. Damn, that's me! This may have confounded any handling changes that I attributed to fuild changes if it had been getting worse for for some time.