It puts a pre-load on the leaf springs.

Joe Fisher
S/S 151

It lets the left rear drive more,  It also tightens the car coming off the corner.

The leaf spring front mounting points act like a 4 bar setup.  The more you raise them, the more drive (forward bite) you will get.  Adding lowering blocks also gets you more drive because you push the spring down towards the track creating more of a spring angle.  The rear part of the spring mount is  adjusted to put the car at the ride heights you want.  Obviosly when you raise the front of the spring up the rideheights drop which is why you see guys lowering the LR spring down in the rear.  Adding blocks also helps drive because it gives you leverage on the spring helping it wrap harder.  The right rear is pretty close to a stock mounting point.  If you raise the front of the RR spring up with the Left spring the car starts to wheel hop and buck.  I would start with a 20 deg upward angle on the LR spring and lower the back of the LR spring down about 8-10 inches to start.  Leave the RR alone at first.

I really appreciate you guys that have been doing this stuff for a while, throwing this kind of stuff out. Since I bought my mod (an older leaf car) I have learned so much about setting it up and ways to make adjustments. have run the car only twice, and I feel the car is loose off. I am going to get more seat time before I change anything, but my list of ideas is growing. I am really looking forward to this challenge in the mod class.

Andrew wrote on 12/19/06 at 5:42am:




Check out the "FASTBOYS"  setup over on 4m.net

And 3d is right it will feel loose off, for awhile

If you want an accurate gage of how the tire affects the car, go to a practice day with a set of G60's and a set of hoosiers.This will tell you what is the tire and what is seat time. You will not feel loose off with the hoosier, but might feel a little tight in the center.

Quote:


I think he was talking about the the street stock hoosiers. There is not much difference between the AR G60 and the Hoosier G60. I only ran on the ARs a few times if any the felt a little better than the IMCA hoosier. I couldn't say for sure because they feel almost the same.

The Modifieds do feel loose. I am not say your car wasn't loose but at the begining of the year I kept trying to tighten up the car untill I figured out my car was actually to tight. I loosened it up and got faster because I was no longer snaping the car loose. Modifieds are a lot different than any thing I have ever driven. They take some getting used too, but they are a ton of fun.