PDA

View Full Version : Crate model role center



smkjoe
05-28-2012, 12:25 PM
Do the Crate late models require a different role center than cars with more horsepower. on a dry slick track our car skates sideways instead of rolling, need some help. our set up numbers are imca late model, they worked pretty good when we bought the car, but wrecked it in the isl of capri races at batesville, car has been a piece every since.
Thanks, Gary.

BRD
05-31-2012, 08:23 PM
Gary it helps to raise right upper a-arm about 7/8" . The rc will be shifted to the left and free the car up on the gas. Are you using a tie down shock and softspring on RF ? Sometimes moving rearend to the left 3/8" - 1/2" will help pin RR. This works for us at West Plaines in a crate.

dynoman14
06-01-2012, 12:08 PM
Knowing absolutely nothing about your car, chassis, driver, set-up or tracks you run this is a pretty generic answer.

First; I would contact the manufacturer of your car and get a build sheet and generic set-up sheet for where you run. I would also ask him for some measuring points so you can determine how far out of wack your chassis is. I would tell you to use plumb bobs but many dirt cars are wacky on front end and rear end offsets so standard ways don't work that well.

Second; I would try and get my wrecked car fixed on a jig where you know it is right.

Third; I would be on the look-out for somebody with the same brand chassis that might lend you a hand with some general set-up info or a capable shop to help you out with your problems.

You can use plumb bobs to see if your rear end is straight, and if it is located in the car square or close. Depending on rear suspension many cars have the rear forward statically and under travel the rear open steers by moving the RR back, LR forward or a combination of both.

Until you fix your car, and determine a baseline set up with the spindles, a-arms and suspension pieces the manufacturer recommends you are kinda shooting in the dark.

Roll centers on a race car are dictated by geometric locations and travel of suspension pieces and pick-up points. Change any one and you will change the whole sha-bang...

In my opinion since you don't currently have the ability to re-engineer your car, your best method of getting it to hook up is to get with a good shock guy to get your car moving dynamically to increase the side bite going into the corners.

There is 100 ways to get that done but in your case the easiest might be to work with shocks, springs and suspension travel to get the job done.

You can pm me and I'll give you my shock guys name and #, if you don't already have one.