killain

I replaced my nine leaf steel spring eight years ago with a TRW fiberglass rear spring. Since then I have a much better ride and it's also quieter. i did have to switch to Gas shocks to control the faster rebound, but I still think changing to fiberglass was one of the best mods I have done on my 79 Vette? FWIW

bence13_33

I've heard that with a fiberglass leaf spring, you need to keep your exhaust out of the way or else it will cause the spring to break. Maybe someone can verify this?

Jack71

I just switched over to the Vette Brakes fiberglass spring with new gas shocks. The ride is much improved and ride height is adjustable.

Its my understanding that the main job of the rear spring is to provide a comfortable ride & correct ride height. I don't believe the spring has much of an impact on handling performance. Thats what your sway bar is for. The combination of a fiberglass spring and beefier sway bar has worked well for me -- comfortable ride, no bounce and nice handling.

Nomad78SA

I also went with the Vette Brakes Performance Plus suspension kit. It comes with a fully adjustable front and rear fiber spring and matching Blisten shocks. It does not attach to the rear housing in this configuration but has it's own two supports that you adjust for spring rate. Have not had a chance to put it on the road yet but I have added other mod's with it too.


1.125 anti sway bar kit
.750 anti sway bar kit
Transverse front spring system including lower control arms
Heavy duty upper A arms mig welded
Adjustable dual mount rear spring kit
Blisten Digressive valved shocks
A complete poly front end rebuild kit
SS trailing arm shim kit
Smart struts assembly
Cross member reinforcement kit Poly differential bushing kit
The kit is $1900.oo at Vette brakes
Put on Hooker Sidepipe Headers to take out the heat concern on the springs. Dropped a built 700R4 from Bowtie for the cruising and a 388CU to put a strain on all the mod's. :D Man, I already have a smile on my face and cannot wait for the days to come.
Neil in Tenn


[Modified by Nomad78SA, 8:32 PM 10/4/2001]

Jack71

Nomad78SA,

--Lookin' Sweet :yesnod:

427V8

Well I have a 355 lb glass TRW spring if anyone wants to buy it...
I think most people go from an old worn out steel spring to a new glass one and think it's great, but switching from glass to new steel made very little difference except for the bounce.

And yes I do know the new Vettes use glass, they are designed to...

flynhi

I've been working on my 71's suspension for the past 15 years. I've tried OE steel, TRW, VB320, VB custom 345 and now back to TRW.
Last year I added VBs front transverse spring.
The secret to satisfactory performance with FG springs is properly matching front and rear spring rates and selecting the proper shocks.
TRW seems to have a slower, smoother rebound rates and has worked well for me with Konis and Bilstein Sports. It has less arch and is easier to adjust ride height with.
VB seems to have a faster, bouncier rebound rate and will not work at all with off the shelf shocks. VB sells custom shocks that work well. VB has more arch and was much more difficult to adjust ride height with.
My current setup is VB front spring on softest setting with Bilstein Sports and TRW 315 at rear with Bilstein Sports.
BTW, Paul Kisinsky of VB told me at the Houston Corvette Show last year that 80% of ride quality in C3s is derived from the rear spring.

SmokedTires

I've been very happy with the fiberglass spring since I installed it 2 years ago. It came w/ the VB Street & Slalom suspension kit. I have the chrome adjustale Carrera shocks that work great.

They do warn about exhaust heat so I did wrap the exhaust where it went under the spring for protection.

Ganey

VB, many of us are running them w/ no problems & no bounce either. VB FE-7 equil. for about 20 yrs., originally installed w/ the long lowering bolts. Currently std. length bolts (it came down some) & Delco Performer shocks.
Have given it a hard life !

:cool:

ddecart

When I bought my car it had a VB 330 lb spring on it with the gas-adjust shocks. That thing was very bouncy. If those were the recommened shocks, someone needs to learn how to tune a suspension. :eek:

I replaced it with a 7 leaf steel spring and the ride is much improved IMHO.

The main difference between a steel and a fiberglass spring of EQUAL spring rates is the presence of interleaf friction in the steel spring. If you compress a steel spring, the leaves rub on each other. This is basically built-in-damping. You have to overcome that friction before the spring does ANYTHING. Small bumps won't get there, so you'll feel those more.

I'm not sure what the force-deflection curves look like for comparable steel and glass springs, although I think it'd be interesting to see how the spring rates change over the wheel travel range.

jsimpson

If your Vette is a daily driver, go with glass. It will mnake your Vette stop riding like a truck and start riding like a car. Why do you think glass springs have been use by GM for Corvettes since 81? I trust Corvette's engineers to lead me in the right direction; I used a used 82 spring on my 78 and it's been one of the best moves I've made!