Spring rates
 

Does anyone have any info on spring rates for a '78? My pace allegedly has the gymkhana setup (dealer installed supposedly) with Bilstein shocks all around. The fronts are not labeled but allegedly the 550 lb/in. The rear has the correct 7 leaf, but I can find no info on the rate for that spring. I'm considering a TRW composite for weight and ride improvement. OEM is 35 yrs old and a bit creaky.

Welcome to the Forum!

Below is a link to GM Archives Vehicle Information Kits specific to your year Corvette. It is a pdf document that contains MVMA (Motor Vehicle Manufacturers Association) and Chevrolet information to the dealer (salesmen).

http://gmheritagecenter.com/gm-herit...tion-kits.html

Click on the link.

Scroll down the page to "Corvette" and click on "Show".

Find the year of interest (in your case "1978 Chevrolet Corvette") and click on that link.

Accept the GM usage agreement, and a pdf will download. Save the pdf for future reference.

Open the pdf.

In your specific case, MVMA Suspension information is on page 59 of the pdf (page 24 of the MVMA document).

Frame and suspension information is also found on pages 87-89 of the pdf.

The pdf contains a lot of other useful information, it is worth a scan.

Hope this helps.

Also available from GM Archives ($50) is a copy of your Corvettes Shipper Document. (1977 and on Corvettes) This contains much the same information as your Build Sheet (tank sticker) listing RPO codes, Dealer Info, Dates, etc. This would confirm if your car came with gymkhana suspension (RPO FE7).

http://www.gmmediaarchive.com

I too have a 78 L-82 4 speed originally equipped with the gymkhana suspension. The OEM 7 leaf steel spring, I recall from the gm heritage link is 292 lbs. I have had a 360 lb mono spring since 1986 on the car. Sooo much better than the steel spring.

Thank you mapman for pointing me in the right general direction, but apparently the General doesn't want anyone to know his suspension secrets. I found the rear spring rate for the base suspension (198 lb/in if anybody wants to know) but no information on the FE7. I did however find all kinds of other useful info which I printed out for my binder, like the official announcement of the production of the Pace Car from Chevrolet HQ and more.

Thanx JB. I've hunted everywhere for that data. I was asking because I was undecided between the 340 and 355 lb TRW's. That 355/360 seems kind of a huge jump from 292 lbs. I assume that the smoother action of the spring compensates for the harshness of the steely even tho the rate is some 20+% higher. I seek a sporty ride, but not something that's going to pulverize my kidneys (and my aging ass). :crazy: