Cobra Geometry Challenges!

[bobcowan]

Originally Posted by DocDirk

Forgive me for not knowing how to do the ride height adjustment, I'll look it up on the web. Any hints for this amatooor?

Depends on your set up. A quick scan of the web site doesn't show much, but it appears that coil overs are an optional component. Without seeing your set up, it's difficult to tell how to do adjustments.

Originally Posted by DocDirk

I appreciate the specs, they've been hard to find. Would that be generic for most all cobras or should I pursue Mustang II front end specs?

Thanks!

Dirk

Those are pretty generic specs, and should work with just about any set up.

Caster is a variable spec. Some people like a lot, and some like a little. A lot will hepl the car return to center a lot easier. That also means it takes more work and effort to move it off center. If you have a bump steer issue, more caster will make it worse. I'v played with differant setting, from 1* to 5.5*. I like the low setting much better.

Speaking of bump steer, have you checked yours yet? Kinda hard to do without getting the alignment close. But it should be on your list to do eventually.

[RICK LAKE]

DocDirk I'm am going to give you another aproach to this problem
The car needs to be weighted first in all 4 corners with you in it. I don't know if your motor is square centered in the car or off to the r/s up to 1". All the has a MAJOR effect on the car and handling.
Measuring the cars corners will get you into the LARGE ball park to start. You need to weight the car with you in it. If possible a 49/51 front to rear bias is a good place to start. I found that measuring the frame from ground to corners had my car over 300 pounds off. This was without my weight in the drivers seat. This is another important thing. Tire pressures need to be all the same or running 2 -4 psi in the front tires over the rear ones.
Once the car weight is done( have 1/2 tank of gas in the tank) Lets look at the alignment numbers. On the street with P/S running +.75 camber L/S, +1.0 R/S. Caster should be about +3.0-+3.5 depending on how tight you want the car to handle. Toe is 1/16 toed in. The thrust angle of the car need to be close to "0" as possible. This will make the car accell in a straight line as long as the bushings are in good shape and not worn to have any play.
If you are going to a race track these numbers will need some work. Measuring tire temps to find out what the car needs and wants to turn and drive.
You dropping the pressure in the rack will do little to change the way it works. The problem sound like the gear ratio is changed between rack 1 and 2. As others have said, bump steering also has alot to do with the car turning. This is easy to do yourself with the gauges and board.
If the car is going to remain a street car the spring rates can stay low 250-350 rate if you are looking for track rates, you will need to increase them by about 50-100%. Going to slicks too.
Stay away from wyotech, there basics will do little to help. The best place is to to fine a dirt tracker you can follow and have things explained. Book teaching and real world are not the same, again a large ball park. There are a couple of suspension books that will help. There are also Suspension programs you can use to help setup the car without all the wrench turning to start with.
There is a small thing you said about having the car aligned, Did you ask when the machine was last calibrated?? If the heads are dropped once, it can knockout the measure ments up to 1 degree. This is alot. Rick L.

[DocDirk]

I take it from your several feedbacks that the weight/frame height adjustments should be made before the alignment is done...is this correct? I can get to the alignment shop this week but the tool for adjusting the ride height won't be here until at least next Friday - will the alignment be thrown out if I make the adjustments to corner weight/chassis ride height afterwards?

Thanks again!

Dirk