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Discussion Starter · #1 · (Edited)
Hi all;
I am a wannabee Corvette owner in the Netherlands, and have been test driving a few cars.
The purpose for 'my' Corvette would be cruising, not racing.
The ride of the rear end can be pretty harsh, as a sports car ought to have, but understand that composite rearsprings can be more comfortable.
Now my question: when I look in the Zip parts-list or on the Ecklers site, I notice that different springs are being offered, and expressed in xx lbs.
Now I assume that a higher spring rate means a stiffer spring, but what exactly does the ponds figure refer too?
Something like one inch deflection for the given pound rate is the nearest I can think of.
Please explain this to me.
And to give me a reference, what is the springrate of the standard rear spring in a late C3?

And while I am at it, what does the optional Gymkhana suspension comprise off, particularly in relation to the rear-end spring.
Thanks a lot for shearing your know-how with me.
Cor
 

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hey Cor,

you're right that the spring rate is actually expressed in lbs/in. All springs are rated in such a manner (not just automotive) and give a good basis of comparison between springs. I have a 330# rear spring on my '69 and think it's a little too soft for my taste but I prefer a pretty stiff ride. A 330# or even a 360# spring should do you just fine with a good set of shocks. A 420# spring will probably be more than you're looking for in a cruiser. :thumbsup:

welcome to DC, and good luck with your search! :cheers:
 

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...what is the springrate of the standard rear spring in a late C3?...
I believe the 68-80 stock rear spring was rated at 300 lbs. The base 81-82 fiberglass spring was about 315.

...what does the optional Gymkhana suspension comprise off, particularly in relation to the rear-end spring...
The complete package consisted of a bigger (stiffer) front stabilizer bar, higher rate front springs, higher rate seven leaf rear spring, rear sway bar, and stiffer shocks front and rear.

:thumbsup:
 

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If I remember correctly - the 330# means it takes 330 lbs to compress the spring 1 inch. So, the higher the rating the stiffer the spring.
 

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Discussion Starter · #5 ·
Thanks guys, you all confirmed that my bit of logics just worked alright for me.
Now one more: on a coil spring, or an ordinary spring set-up, it would be simple, a load of 330 lbs will deflect the spring by one inch; however, the traditional set-up works one one spring, and thus on one wheel.

Not so with the Corvete!
It either would mean, that 330 lbs on the spring will get the car down by one inch
OR
330 lbs. on ONE springtip, will get one side down by one inch.
What's correct?
Thanks,
Cor
 

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hey Cor,

you're right that the spring rate is actually expressed in lbs/in. All springs are rated in such a manner (not just automotive) and give a good basis of comparison between springs. I have a 330# rear spring on my '69 and think it's a little too soft for my taste but I prefer a pretty stiff ride. A 330# or even a 360# spring should do you just fine with a good set of shocks. A 420# spring will probably be more than you're looking for in a cruiser. :thumbsup:

welcome to DC, and good luck with your search! :cheers:
:agree:
I've got a 360# VB&P spring and it's perfect for "spirited" street use. A little more firm that my old stock steel spring, yet less harsh of a ride.

Matching the correct shocks to the glass spring is also important. My GM shocks are a bit bouncy with the glass spring compared to the steel spring. Swapping to Bilsteins is in my plans.

:cheers:
 

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I believe the 68-80 stock rear spring was rated at 300 lbs. The base 81-82 fiberglass spring was about 315.



The complete package consisted of a bigger (stiffer) front stabilizer bar, higher rate front springs, higher rate seven leaf rear spring, rear sway bar, and stiffer shocks front and rear.

:thumbsup:
From the Duntov website and from what I know having owned my 78 L-82 gymkhana C3 for 27 years:

"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". This was the base spring in 78-80.

The 78/79 F-41 vettes had 292 lb 7 leaf rear springs. the base corvettes in those years (78/79) had 9 leaf steel springs rated at 260 Lbs.

The 80 L-82 sport suspended vette had a 7 leaf steel spring (260 lbs like the 78/79's and the base corvette had the first year of the composite spring-196lb. Beginning in 1981 and continuing with the 82 vette, the spring rate was 192 LBs (composite for all the vettes) since GM had decided to make the corvette more luxurious and less sporty. The 81/82' were very softly suspended versus the other year C3's The 78/79's were the last year of C3's having a true sport suspension.

I have had a 360 composite on my 78 since 1986 with Billstein Sports in the rear. The ride is infinitely better even with the bilstein Sports (30% stifer than the Bilstein HD's) compared to the 7 leaf steel spring.

Just wanted to be clear.
 
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