Originally Posted by ganshert

Some interesting info on the subject from an online vendor that sells both steel and composite springs.

"Composite vs. Steel Rear Leaf Springs

A couple of times a week we are asked to give the plusses and minuses of composite vs. steel rear leaf springs. This is how we see it:

The TRW spring is the OEM replacement spring for the 81 and 82 Corvette. From 1963-1980, Corvettes came with steel rear leaf springs. In an effort to shave weight off the car to help with fuel economy, for the 1981 model year Chevrolet went with magnesium valve covers, a composite rear spring and a number of other weight saving substitutions. The spring change saved about 20 lbs; a huge savings for comparatively little money. To the end user, the twenty pounds is equivalent to about two and a half gallons of gas; not exactly earth shaking for the average Corvette driver.

Unfortunately the composite spring weight savings was right where the Corvette least needed to lose weight; low and behind the rear axle. The steel spring is like ballast in a racecar, right where it needs to be; low and behind the rear axle.

Composite springs don’t lose their spring rate over time. A 315 lb spring will stay 315 lbs until it breaks. Yes, that’s what sends composite springs to the dumpster; a rock in just the right place. Hit on edge by a road hazard, a composite spring will often de-laminate. It will turn a milky white at the point of injury and its service life is over. A steel spring will slowly lose its spring rate over time, but it will never break.

The softest TRW composite spring is 315 lbs. Most C2 and C3 Corvettes came with 196 lb. steel rear springs. After 20 years or so, when they are ready for replacement, their effective spring rate has eroded by as much as 40%. Replacing the original spring with a new stock steel spring makes a big difference; a 40% difference. Changing to a 315 lb spring would be a change of 270%, and you would have a completely different automobile.

The spring rate of the 78-80 OEM factory steel rear spring was 260 lbs. You can order a 315 lb spring for a 78-79, but for anything newer than that, you have to chose between 345 and 355 lbs. That’s a heavier spring rate than we run on our racecars, so you can imagine it’s not the softest ride on the planet.

One more thing that may or may not be a big deal to a street driven Corvette: The steel spring is at least somewhat progressive in its spring rate. In our custom steel springs that we use for our racecars, we individually arch every leaf to achieve an almost linier rate progression. This helps handling a lot, and we see it in our lap times. Obviously that’s not possible with a composite spring.

In summary:

Composite spring Advantages:

• Light weight
• Permanent spring rate

Disadvantages:

• Cost
• Durability
• Limited spring rate options
• Often much stiffer than stock"

Originally Posted by DUB

As we all know the new Corvettes have composite springs....and I rarely hear anyone 'saying' that the ride sucks. And on some of then that have ride control which changes the dampening of the shocks. So having rear spring with a higher than stock spring rate does not always mean that the ride will suffer.

Steel rear leafs springs or composite rear springs....it seems that this is where people clearly have their own views. It is like an original AM/FM radio or one that has been gutted out and upgraded. Both play music effectively...but the quality of sound can be different. The same holds true in rear leaf springs. Both work but some people prefer one over the other.

DUB

Originally Posted by colo63sw

I for one can clearly state that the ride of a C6 sucked so bad I got rid of it. I happen to live in an area of town with poorly maintained roads.
I think that people with C4-5-6 & 7’s that say they ride good live near roads that are new/carpeted.

Look on the C4 – 7 forums and you will see a lot of comments about poor rides.

Originally Posted by DUB

I do know that many people do not like the ride and comment on how bad it is.

I agree if the roads in that persons town are crap. Like if a person where driving over train tracks all day long ...I feel is an unfair comparison. Heck on bad roads an SUV will still make you feel your kidneys are about to pop out. And they may have wider sidewalls on the tire and more suspension travel.

So...either have a car with a great ride on really bad roads but then they would complain about how it handles in the turns and it is not crisp enough.

I can say that it is a balance that is often times hard to achieve...if that person is trying to get a Corvette to fell good on bad roads and handle as it should.

I am sorry that you had to sell your due to how the ride was. Getting all excited on getting it only to find out that it just does not seem to work well....had to suck.

DUB

Originally Posted by colo63sw

Yes, it did suck.
I believe a balance can be achieved.
My Pantera drives the same roads with ½ of less of the jolting ride; I had a 1997 jaguar XK8 that cornered like a cat and rode very nicely on the same roads. Comparing the suspension between the jag & the C6 looked like the difference between a 60K car & a 30K car.

I think the ride in a modern vette could be better. It’s short wheel base, low CG & fat tires will always corner well. Form the C4 on up chevy should have had 3 suspension options; gentleman’s, performance (standard) & Z51. Z51 is for those that want to drive their car to the race track.

Originally Posted by 66BlkBB

I had one on a 72 coupe that I owned. Did not like it. I believe it was the 300 lb unit and it rode stiff. My 66 with the 9 leaf spring rides great. I wouldn't even think about installing a composite unit in it. JMO