Rear suspension way tooo low and front too high...need help and suggestions!

Rufblackbird · 04-04-2005, 10:35 PM

Hey all,
Recently I did a lot of suspension work...coilovers, aluminum trailing arms, elephant monoballs, and erp 935 spring plates. When I dropped the car back down, holy crap, the rear end is WAY too low. The TRG inverted coilovers (18" ones) are adjusted to its highest setting. What do I have to do to raise the rear end back up? Go for the 20" coilovers instead?

Also, the front suspension is way too high. I read the lowering part in the 101 projects book and did everything according to what it said but it still is way too high. I'm just stumped...

Any ideas/suggestions appreciated...thanks!

petevb · 04-04-2005, 10:39 PM

What springs are you using front and rear? Length and rate...

Rufblackbird · 04-04-2005, 10:42 PM

hmm...no idea. I bought the rears from a member off the classifieds. Fronts are still stock torsion bars.

petevb · 04-04-2005, 10:49 PM

It usually lists the spring rate on the spring someplace with a code. It would be really good to figure out what those springs are purely so you know what your setup is.

In the rear, if the shock is not compressed at all and the spring collar is all the way down is the spring already compressed a fair bit, or is it loose?

Jeff Alton · 04-04-2005, 11:04 PM

That is kinda screwy. Those are 400lb springs on there. My car was right at about 24 3/4 in the rear when I had those in there. The spring rate is stamped into the top of the spring where it is flat and rests against the perch. How much does your car weigh? THe adjuster is all the way to the top? Anyway you can measure the lenght from the top of the clevis to the lower mounting eye with the suspension loaded and compare it to the length when it is at full droop or unloaded? Then we can see if maybe there just is not enough spring rate. I am intersted to know how much the spring is compressing. Also those are 8 inch springs, which are recommended with the 18 inch rsr set up but maybe a 9 inch one would be better......

Jeff

Rufblackbird · 04-04-2005, 11:40 PM

just checked...the spring does not move at all.

Jeff-
My car should be pretty light...bumpers, fenders, quarter panels, and tail are all fiberglass, and I've got my single Recaro PP seat with a regular passenger seat. Car is a '72 T with a SC motor. Adjuster is all the way to the top, near where the threads start to run out. I'll try to measure the length of it compressed and unloaded. Thanks!

petevb · 04-05-2005, 12:04 AM

First thought is that the springs are too short, but... That rate is plenty high that you won't get much sag. If you can put a market on the shock (a zip-tie works well) when the weight is off the shock, then see how much it moves when you weight the rear you should be able to tell...

Jeff Alton · 04-05-2005, 10:28 AM

The lower perch is quite long so the top of the lower perch could be turned up beyond the top of the treads on the shock body still leaving plenty of thread to thread contact between the perch and the shock body. I also had helper springs (zero rate) so I guess when compressed they would add 3/4-1 inch of height to the car as well.

Perhaps a 9 inch spring would do the trick...

Jeff

Rufblackbird · 04-05-2005, 12:36 PM

thanks, I'll go give the helper spring a shot; if that doesn't work where would I be able to get a 9 inch shock?

petevb · 04-05-2005, 02:36 PM

9 inch spring, not shock, and if you pulled the helper spring that's your problem with the rear. Smart racing was selling used springs for $25 each for a while- you could see if they have a 9" or 10" by 400# spring in stock. Any of the race shops (TRG, etc) should be able to get them.

Gumba11 · 04-05-2005, 03:41 PM

Quote:

Originally posted by petevb
9 inch spring, not shock, and if you pulled the helper spring that's your problem with the rear. Smart racing was selling used springs for $25 each for a while- you could see if they have a 9" or 10" by 400# spring in stock. Any of the race shops (TRG, etc) should be able to get them.

Very good point! I run 650# with no helpers and have not measured mine but they are designed to run without. Bilstein/Hypercoil combo. If you are missing a helper spring then that would be an issue if they were designed to have them.

.............................................C

Jeff Alton · 04-05-2005, 06:15 PM

They are not missing, the spring was a zero rate just to hold the main spring in place while the suspension was unloaded. For 9 or even 10inch springs try The Racers Group and talk to Paul Carver. He knows me well and will help you out there.

Jeff

Rufblackbird · 04-05-2005, 06:24 PM

Thanks guys....so with 9" or even 10" springs they would fit the shocks and the ride height would be increased? If so I'll give TRG a call as soon as I reach them. Thanks!

Jeff Alton · 04-05-2005, 06:31 PM

Yes, in your case the helper spring (tender) would always be compressed adding maybe 3/4 inch of ride height. Better to use a longer spring I think. What torsion bars are you running or planning on running in the front?

Jeff

Rufblackbird · 04-05-2005, 07:34 PM

Eventually I'd like to run coilovers in the front as well...but that's gonna be a while until funds replenish. Longer springs would fit without a problem at the highest setting?