Cal-Trac questions?????

[supernova]

We don't talk about Cal-Trac and leaf spring set ups on here much.

I have a set of Clavert split mono's on my car. They seem to be real stiff. If I preload them with the Cal-trac's won't it make the spring seem even stiffer?

We put a 1/4 turn of preload in them for test and tune friday and now I'm wondering if thay shoud have some air space instead of preload.

What do ya'll think?

[BracketNova]

I put weight in my drivers seat and tighten them until I can't spin the crossbar. That has always worked best for me. If I notice the car doing funny things, traction wise, I double check it and it has always been off. I reset it and away I go. . But, your going to hit the tires harder than me probably? I do use a tbrake though.

[Speedster]

Alot of the guys up here use them. and the stock and super stock cars seem to love themon the novas and camaro's.

[John_Heard]

The main difference adding more preload to the bars is it will stiffen them, which in my opinion will create more initial shock at the tire. Less preload will dampen the initial hit at the tire a little.

I forgot, what tire do you have on the car?

[Craig W.]

I currently have a 1/2 turn of preload in my driver's side bar and 1 turn in the passenger side. The difference in preload is just to make it go straight.

[John_Heard]

Craig did you ever put an anti-roll bar in your car?

I think the problem with the leaf springs is they can have some rear steer in them due to the differences in length of the springs when they wrap up.

[Craig W.]

No, I never did put a swap bar in it. Its still real basic, just like the last time you saw it.

[supernova]

I'm running a 275/60/15 drag radial M/T.
The preload might not work for this tire I'm going to try it with some air space instead of preload next time out.

[John_Heard]

Oh yeah, forgot you're running radials. How the car works is going to change dramatically when you start spraying it, just something to keep in mind. From what I've seen with the small radial most of the cars seem to run the bars in the top hole, indicating they are minimizing how much the rear end moves = smacking the tire hard initially, which should also mean they're not running a gap either.

[supernova]

I think I'll try it with a little air gap (a nickel's thickness) to give the pinion a chance to rotate some. I also will try to hit it with the t-brake at a lower launch rpm and see if that makes it move.

[ytnova]

I never could get my car to work that well on the 275 mickeys, way too inconsistant. It was due to both the track temp, track prep, and having single adjustable rear shocks that I could never get stiff enough to control the hit. My problem was it would take the initial hit, role about a foot and then unload. It wasn't until we started videoing the car that we could actually see it bounce the rear tire off the ground, while the fronts were still in the air. I switched over to the hoosier radial and invested in some good custom valved DA shocks and it made all the difference. I run the bottom hole with 1 full turn of preload on each side. Leaves at 4000rpm on the brake, hooks everywhere on motor and damn near everywhere on spray.

[71Hellride]

Hey ytnova how fast have you been with that setup. It seems the question to run the top or bottom hole is up in the air. I've seen fast cars both ways.

[John_Heard]

Top or bottom hole is solely based on car color...

[ytnova]

I have to agree with john on that. Some cars like the top and some the bottom. It seems to depend on the tire size, tire type, car weight and where the weight is. I am not aware of anybody having a definative "rule of thumb" for it. As for the car, its been 5.70 with a single stage plate and a class limited .073 jet in the 1/8th, and 8.80's in the 1/4 on the same tuneup, both at a svelt 3500lbs. The car is geared for the 1/4, but lately I have been doing only 1/8th mile stuff, so I think a gear change is in order. But I also am having some problems with the nitrous/cam combo, the car barely picks up from 200 to 400+ worth of spray, it is using the nitrous, we weighed the bottles, and the tuneup is good, it just flat is going out the tailpie and is the wrong cam. A cam swap is first on my agenda.

[supernova]

Hey ytnova,

What springs are you using? I'm running the split mono's from Calvert. They seem pretty stiff without preload. A lot stiffer than the stock mono's I took off the car.