dougn

I had been studying suspension options for some time and finally went the Bilstein/H&R route....except I had the Bilsteins revalved for the increased spring rates of the H&Rs. i know this is commonly not done but Bilstein states on their web site that there dampers are good for +/- 20% spring rates. given the H&R rates are much greater than 20% stiffer, and I can't stand a bouncy ride, I opted for the revalve....Bilstein increased the rebound dampind and left the compression alone.

anyway compared to the original set-up (57000 miles), well there is no comparison.

i installed the front springs with the preload rings all the way loose. the resulting front ride height is at least 2 inches lower than before. i preloaded the rear where about .75 inch of thread at the bottom of the damper...i'm not sure how much lower the rear end sits now (haven't measured it). i got lucky and got the front end at -1.5 degrees camber both sides. i didn't measure the rear end.

the car is much less darty when driving 80 or 90 mph down the rain grooved, uneven freeway...i guess you would say it's stable. it's now a pleasure to cruz at moderate speeds. on rolling, twisty, bumpy(smooth bumbs that compress and work the suspension), the car handles much better but there seems to be some tendency to dart around in the bumps. i'm thinking this must be bump steer. is there a rack spacer for a 964? i'm thinking of increasing the preload/ride height by about .5 inch in the front and rear...i wonder if that would make a significant difference in the bump steer geometry

in general, what effect does front toe in/out have

Colin 90 C2

The preload rings you are referring to are for corner balancing. It is usually advised to position them where they were on the old setup. This will usually get the corner balancing close.

From my experience, the springs will actually do the lowering. The preload rings I think only adjust the car +/- .25 to .5 in total.

If you car is out of balance, you may notice that it may turn in better to one side.

My advice is to set the rings back where they were.

Marv

Better yet, get it aligned and corner balanced.

dougn

from a simlple physics point of view spring preload adjustment enables ride height adjustment and corner balancing. i don't think there is anything meaningful about the preload position with the original springs.

i think lower is generally better for handling with the limiting factor being bump steer. also, from my experience and reading about other's experience i think most alignment shops are incompetent.

anyway i intend to experiment with ride height all around and camberand toe on the front end by simple measurements in my garage. i want to know if anyone has any experience with bump steermidigation