Chump car lowering

#1

Building an E30 Chump Car, has anyone cut springs to lower an E30? I know its not the right way, but the only thing Chump Car allows. The front is no problem but if you cut the rear, you lose the locating point. Or did you just run the stock height?

#2

Cut 'em and make sure they are sitting in the guides correctly as you lower the car after jacking it up. They wont come loose unless you go airborne in which case the springs are probably not your primary concern at that point. I have some cut springs from my E30’s previous life as a GTS1 if you want them.

#3

Cut the springs and you have 2 options. First would be to add a limiting strap so that the control arm will not drop far enough to loose the spring. Second would be to weld the spring to the upper mount, or lower mount, about an inch of weld will do. Just do not weld top and bottom becuase the springs rotate and will bind and will probable break the welds.

Peter Thibault

#4

WRONG!!! Put jack stands under the suspension to support the car without the wheels. Put wood under the pinch weld allowing room for chassis to drop (5 1/2" front, 6" rear at the pinch weld) and heat the spring with a torch…let cool naturally.

#5

I always thaought heating would make the springs break eventually.

#6

Eventually they will all break! Heat evenly over a 2-3 inch area and let cool gradually…been doing that with sway bars for years!

#7

Forget cutting the springs and pick up a set of used M3 springs.

#8

Won’t lower car

#9

M3 springs won’t lower the car a lot, that is true, but they will lower the car just enough imo.

You dont’ need the car slammed on cut springs bouncing off the bump stops for it to handle very well!!!

#10

In lowering the car, you are changing the roll center and optimizing the LCA angles. If you lower to 5 1/2" at the front, and 6" at the rear, you have optimized the stock suspension, but what do I know?

#11

What part of the spring is the best to heat?

#12

One of the long center coils.

#13

M3 springs are .75" lower. I ran them on my road car. The rears were great, the fronts were good but did bottom rarely, given that heavier M20. I think they’re only about 4lbs stiffer up front.

Lower isn’t necessarily better. You need a commensurate increase in stiffness along with it. I’d rather have something that sits taller than something with a lower CG that’s bottoming. Remember, just because you don’t feel a thump doesn’t mean it’s not bottoming–it could gently settle on the bump stops in a corner and the only symptom you’ll feel will be the car letting go in corners.

Cutting out dead coils is effective, but you must make sure it’s only the dead coils you’re cutting. Easier said than done.