Ok, I've gone over the new car's suspension and I've found something I don't really understand. My old car had 8" hyperco hypercoil springs in the front and 8" carrera's in the rear. Why? I dunno. That's just how I bought it. 350lbs front, 325 rear.

New car, same manufacturer but different rates. Unknown front and 300 rear. And, the new car has 12" hyperco's in the front and 10" carrara's in the rear. I just ran it at driver's school and the last 2 events as it was, but now its time to get to a known baseline and start from there.

I'm going to purchase a few sets of springs to test with, starting with katman's series of springs and a couple of David Spillman's as well. Maybe 325/275, 350/275, 350/285, 400/300 and 400/350.

Here's the questions. Is there an advantage to longer coils? The fronts are almost out of room on the adjusters (but the car is low enough) and the rears are similar. Do longer coils have better progession? Or do they bind easier due to more coils? I have found that the 12" coils weight about 2 1/2 pounds more than the 8". So there is at least a weight savings on the smaller springs.

I was going to go with possibly a series of 10" or 8" with the front and rears being the same height. But I'd like to know the trade offs in each direction if anyone knows.

Another question is.. Hyperco or Eibach or Carrera or Landrum? Any feedback on manufacturer?

The last two sessions at Road Atlanta the car was real twitchy in the esses and even in turn six, where I spun. And I've never spun in six. The setup was an unknown spring rate in front and 300 lbs in the rear, with 8 year old tires. (which may have been the problem, besides rusty driving)

Thanks in advance,

Tom

Oh, and the car is a 1970 240z, Bilstien shocks, speedway front bar and no rear bar.