Lowering Springs and Drag racing

Does anyone know what the spring rate is for stock GN rear springs?
And the spring rate of Eibach rear lowering springs?
Is there a supplier of rear springs with various spring rates for the G bodies?

What about using the stock springs, but with relocated or adjustable top mounting locations?
 
I tried a set of simple spring compressing clamps, one on each side to lower the car 1". It worked pretty good. Very inexpensive too. I think I'm going to get another set so I can use the two clamps to effectively change the spring rate by how they're spaced across from each other on the same coil. Using two clamps will also divide the work each has to do to lower the car the target one inch.


Don, I've used those clamps in the past. I found that they seem to move around and change position on the spring upon compression.

Have you not considered using coil over springs ? They're cheap and come in various spring rates. They fit right in with their 2.5" inside diameter. I put in QA1's 110-14. Dropped my car 1 1/2 " The 130-14's dropped me down 3/4". Yet to be tested at the track though. The QA1's give you a lot more room back there for tailpipes, if that' important at all.

These drops are compared to the stock style cargo springs that I had in before.

Dusty Bradford runs QA1's 130-14's last time I talked to him. He runs in the
7's as you know, with stock style suspension, so they obviously work.

Alternatively, you could go to coil-over shocks which give unlimited ride height adjustment.

Having said all this, if you are getting 1.28 60 fts. with stock style suspension, we should be paying attention to what you are doing, not the other way around.;) but I really appreciate your constant search for improvement. Many of us have learned a lot from your willingness to share.


George
 
Thanks George. I appreciate the compliment. And the same back at you for helping to teach the polly wog of G-body suspension setup.
I'm perceiving that 1.28 60 foots are hard to come by. I'm starting to feel pretty lucky since I know squat about chassis setup. I'm willing to bet that the 1" higher upper control arm mounting at the axle housing had the most to do with it. Believe me, it was by no input on my part.

Thanks for the info on the springs. From what I've read up on so far, a good starting point for my weight car would be 110# springs.
I'm guessing that 110-14 would translate to 110# rate and 14" length. Is the 14" measurement unloaded or loaded? And if loaded, how much weight?
So a lot of people just replace the wide OEM springs with smaller OD springs? I suppose why not. A spring is a spring. I'm sure the larger number of coils allows for a much lower spring rate.

Can you see any problem with using spacers under the spring if a particular spring drops the car down too much?

Off to study some more sites. Thanks again.
 
Thanks George. I appreciate the compliment. And the same back at you for helping to teach the polly wog of G-body suspension setup.
I'm perceiving that 1.28 60 foots are hard to come by. I'm starting to feel pretty lucky since I know squat about chassis setup. I'm willing to bet that the 1" higher upper control arm mounting at the axle housing had the most to do with it. Believe me, it was by no input on my part.

Thanks for the info on the springs. From what I've read up on so far, a good starting point for my weight car would be 110# springs.
I'm guessing that 110-14 would translate to 110# rate and 14" length. Is the 14" measurement unloaded or loaded? And if loaded, how much weight?
So a lot of people just replace the wide OEM springs with smaller OD springs? I suppose why not. A spring is a spring. I'm sure the larger number of coils allows for a much lower spring rate.

Can you see any problem with using spacers under the spring if a particular spring drops the car down too much?

Off to study some more sites. Thanks again.

I know squat about chassis setup is this a pun ?:rolleyes:

Yes, the 110 and 130 are spring rates and the 14 is the free length. Stock springs are 14" free length too.

The rear weight of my car is 1536 lbs.

Can you see any problem with using spacers under the spring if a particular spring drops the car down too much?

Not at all. I've used billett aluminum spacers under my rear springs for several years. I've used them to keep my springs preloaded on the top spring saddles. Ever since I put the 9 inch in, the diff drops down farther than the stock diff did when I put it on the chassis hoist and the springs dropped out of their saddles.

I too, know squat about drag suspension but I'm learning fast, with a lot of help from this board and others.

George
 
No really. Up until the start of this thread, I really had no clue. This thread got me going on learning more on chassis setup. I just visited the QA1 site. Now I know about springs.
I think the hot ticket is going to be the coil-over conversion kit. Since I'm going to be cutting up stuff for the frame notching and the anti-roll bar real soon, might as well throw the coil-overs in too. I can't pass up the adjustability feature for the ride height. I'm going with the 130# springs.

Also, scratching off the old sway bar and the air bags.
 
No really. Up until the start of this thread, I really had no clue. This thread got me going on learning more on chassis setup. I just visited the QA1 site. Now I know about springs.
I think the hot ticket is going to be the coil-over conversion kit. Since I'm going to be cutting up stuff for the frame notching and the anti-roll bar real soon, might as well throw the coil-overs in too. I can't pass up the adjustability feature for the ride height. I'm going with the 130# springs.

Also, scratching off the old sway bar and the air bags.


Don,

might as well throw the coil-overs in too. I can't pass up the adjustability feature for the ride height. I'm going with the 130# springs.

Good choice I think. I should have done this too, in retrospect.

Don't forget to record where your insant centre is right now, as a reference point, before you start making changes.

You're launching pretty good now so you'll want to improve what you already have, not make it worse.

Just a thought.

George
 
Don,

might as well throw the coil-overs in too. I can't pass up the adjustability feature for the ride height. I'm going with the 130# springs.

Good choice I think. I should have done this too, in retrospect.

Don't forget to record where your insant centre is right now, as a reference point, before you start making changes.

You're launching pretty good now so you'll want to improve what you already have, not make it worse.

Just a thought.

George
Very good point. Thanks George.
 
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