Technical Help! Drag Car Suspension Problem

And try to jack up 1 side of the axle too. Or, just rock the car hard on one side and see how far it articulates. My guess? More than a car like that should. Get the diagonal link...

I hid the car out of respect for the board, but I had a ladder bar gig under this, farther apart than your deal, very little articulating, and with the suspension hanging loose it went up and down almost as a unit. You'll always have some otherwise it would break, but it has to all work in harmony.

 

Why run suspension? Just a question. Lippy

 

Good question,
I didn’t build this chassis and I don’t know why decisions were made.

 

lippy said: Why run suspension? Just a question. Lippy
AldeanFan said: Good question, I didn’t build this chassis and I don’t know why decisions were made.

Uh, because a short wheelbase, stiff cage and frame, bodied race car will not flex like a dragster, which means it will either have stiff 60 PSI tires and skip over the surface, or bounce uncontrollably on the typical 10-20 PSI thick soft drag slicks. Been there, done that. How many hardtail doorslammers can you point to?

 

Well, first off I don't even know what kind of car it is. lol Is this a doorslammer?

 

It certainly was after it got the shortened 64 Mustang body installed, and was named Colt 45.

 

My experience with this type of issue often is caused by a suspension that's too soft. Any tiny movement of the steering wheel is magnified at high speed, and the car can become extremely erratic at speed.
It could be just the front being too soft, or front and rear both being soft. I would put the tires and wheels back on it, and put it on the ground. Then push from one side up near the drip rails and see how much "roll" the body has when trying to push is sideways.
The springs on the rear coilovers might be able to adjust in more preload, but may need to switch to heavier springs. Not sure what's up front, but a friend had issues with his tube axle's leaf springs up front that did the same thing around 140-150 mph, and he had to add coilover shocks to his parallel leaf setup to get it firmer and stabilize it. But it fixed his problem, and his car handles great at high speed now.

 

This is actually a contentious issue between my friends and I.
Some of us want firm suspension while others want very soft suspension.
I think the car has 120lb rear springs which to me seem light but others think that’s about right.