Fiberglass Monosprings

[Corvette Craig]

I'm hoping to here from members who have had this rear spring installed.
How much better is the ride?
Is this spring worth $300.00?
How much to install?

I already have new shocks, and the ride got ALOT better, but I'm wondering if 300 plus dollars is worth it.

 

[Tom73]

Craig,
Is you '81 an automatic? If so it already has the 'glass rear spring unless it has the gymkhana suspension. 81 introduced the fiberglass reinforced rear spring as standard on automatic cars with standard suspension.

I have two 73's, one with steel spring and the other with the 'glass spring. The 'glass rides much better. But with 'glass you need gas shocks as the rebound is much quicker and you need a high quality gas shock to control it.

tom...

 

[Corvette Craig]

Tom

I must have the Gymkatha, because I have a steel spring.
Are you saying I would have to buy shocks too?
I don't remember what type I put on, although I do remember that they weren't cheap ones, more middle of the road.
I want to get as smooth as a ride as I can get, do you think I could leave the shocks as is for now, and revaluate after a spring is installed?

 

[Tom73]

Re: Tom

I want to get as smooth as a ride as I can get, do you think I could leave the shocks as is for now, and revaluate after a spring is installed?

I would install the spring with your current shocks to see what the ride was like. Generaly the 'glass springs have a faster reaction time then the steel spring so will need a shock with a good response rate, quicker then needed with a steel spring. If you have already upgraded to a higher quality shock with quicker response time, then you should be okay. If the ride is "bouncy" then you will need better shocks.

tom...

 

[Hijinx]

On my '73 I did the fiberglass mono-spring conversion and stayed with the KYB shocks I had in place. The back end seemed pretty soft. I switched over to Bilsteins and handeling is much better. However, while I like the ride, some may say it is rough.

Now, all this said, I have the 330 lb spring. You can go heavier or lighter. I think if your looking for ride improvement, get the 330 spring and a set of KYB Gas-Adjust shocks. If your looking for performance get the 330-340 spring with Bilstein shocks.

Call the guys at either Vette Brakes are Guldstrand Motorsports, either of them can help you with your decision.

 

[KANE]

Go for it-

Get the fiberglass spring- you'll never regret it!

 

[WayneLBurnham]

I switched from the 330 'glass to a 7 leaf

I recently had a rear end changed - the only "ultimate-end" part I've put on the wee beasty to date.

(Wanting a monster-powered stroked BB one day, I wanted the strongest IRS suspension I could get, so I went with the Tom's Differential 12-bolt with 3.70's, which pretty much nuked the 'ole CC's by itself. )

Not having enough credit left right then to even put on the "1480"
0.135" axle kit at the same time, I DID at least have enough to change the anemic spring, which was a 330# fiber spring.

I had intended to go with the #360 - or there is like a #420 or even heavier listed in the VPB catalog - but my vette shop talked me out of it.

When I get sidepipes for der oberstmotor, I WILL go back to the fiberspring, and that's the hint of why my vette dude doesn't like them on the rear - while he does like the front transverse leaf conversion which also uses the fiber springs.

Heat.

Even with the insulators of several designs and with a nice 2.5" pipes, the fiberspring is awfully close to the pipes.

I had been concerned with this when my muffler shop had been doing some work back there, and it was the opinion of the vette shop dude that the fiber spring was likelier to experience heat degradation than the steel spring.

I have to say I preferred the ride of the fiberspring, although like not bottoming out all the time. The action is definitely different (as one other responder mentioned.)

Cost is a factor - the HD 7 leaf (which is 420# I believe) is only about $100. The fiber (in any weight) is $300. The weight is WAY in favor of the fiberspring, but that heat concern I feel is valid with under-body pipes.

Now if only my trusty, heavy, cheap, strong REALSTEEL spring had managed to prevent my driver rear wheel from blowing off the car at 80, things would have been MUCH better!!!

 

[aussie_stingray]

hey there fellow vette owner all the way from Australia!!!
i have a '76 vette.. where i got parts from Vette brakes.....and installed myself.. i have the 330lbs glass spring... its the best upgrade i have had .. it loosens up soo much weight off the backend.. and i left the spare wheel off. which lets even offloads even more weight.. i havent gotten around to changing shocks.. but it it does bunny hop over the bumps etc.. but its very steady around corners.. a real beauty to drive!.. just go for a larger sway bar and harder shocks and u will not regret the move!!!

 

[Tifton81]

Mono Spring

I have an 81 and as of last week installed a new differential, u-joints, bushings, shocks and mono spring. The car now has the original ride hight and it is diffinitely an improvement in the ride. I had a 77 vette and the 81 with the mono spring rides much better. I'm in the process of restoring (as fast as the wallet will allow) and this is by far the best investment so far.

I also completed the front end at the same time.

Happy Trails

 

[sscam69]

The install came with the gear change. You have to drop pretty much everything to get to the differential.

I went with the 330# spring and heavy duty shocks (not to sure which brand).

The ride is definitely smoother and the handling has improved. The car is not "rough" over spots and feels kinda cool when going over speedbumps. But I think its a result of where you sit in relation to the rear.

Frank