Fiberglass vs Steel Spring

[dolamiti]

Hello all, I plan to run a 3" system from my hooker super comp headers back . I have a healthy big block 550hp 576lbs. Has anyone incountered a problem with the exhaust being too close to the Fiberglass Transverse spring and how does it ride and handle.
I know the weight difference 8lbs vs 40lbs is attrative but how does it stand up to "occasional" hole shots and slamming 2nd gear?
Thanks a lot,
Ron

 

[Jack]

I do not have direct experience with glass springs ... but too close to exhaust-high heat will cause glass spring to delaminate & fail ... I've seen it. Can't offer anything on how it'll handle gear-slammin'.
JACK:gap

 

[WayneLBurnham]

Spring much superior, but you must insulate it

This is yet another benefit of sidepipes...

I put on the dual mount adjustable thing from VBP after the silly thin sping hanger bolt on one side broke (I replaced THOSE with nice 7/16" or 1/2" NF Grade 8 thingies).

I took great care to wrap the exhaust and or parts of the spring itself with first header wrap then aluminum flashing so that no part of the two were not insulated from each other. It wasn't too hard to install and made me wish I had done the front myself. I didn't feel the factory insulator things really cover enough.

I'll try to take a pic in the next few days, now that I probably know how to post them....

Those springs are easily as strong as the steel springs otherwise. You are driving the plastique fantastique after all, have a little FAITH in the holy glass!

For heavy launches though, I'd stay away from the lighter ones. That's usually the reverse of what you want (monster stiff springs on the rear of a drag car, which can amplify wheel hop in solid axle cars) but vette IRS's need the extra strength and suck down instead of hop anyhow. Go with one of the super heavy ones or better, the adjustable dual mount system for such higher power levels.

 

[AKRAY4PLAY]

Ron,
you want a light rear spring for weight transfer. go with a 300 adjustible glass spring. the VB&P dual mount is rated at 300, 310, 330 & 360 pounds depending on what hole you mount the hangers from. as for 3" out the back, you may want sidepipes. 3" is hard to get clearence under the diff without being so low that it scrapes the ground. another problem is heat going into the diff. a lot of guys forget about how hot a diff can get, a blown rearend on a Vette can be a very dangerous thing. as mentioned, KEEP HEAT AWAY FROM GLASS!! the glass spring is more like 3 pounds and requires different shock valving since it reacts so much faster than steel. i hammer the crap out of my VB&P dual mount with 606hp and 588tq. just make sure you have good strut rods. Brian