82 rear spring rate?
Thread Starter
Melting Slicks
Joined: Jun 2011
Posts: 2,096
Likes: 15
82 rear spring rate?
When I first bought my 82 I had to replace the rear leaf spring because it was cracked but in doing so I had not researched exactly what was needed. I purchased the 355lb spring and the rear has sat up ever since. I eventually changed out the bolts for longer ones and still can get the *** end to come down. So does anyone know exactly what spring I needed? Is that the right one or should have I bought the softer one? I have about 3.5-4" of gap from the top of the tire to the wheel lip. This car has base suspension.
Race Director
Joined: May 2006
Posts: 18,734
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from what I can see the original was 260 but the softest composite for 82 is 345
http://www.duntovmotors.com/rearsuspension.php
you have stock wheels and tires?
http://www.duntovmotors.com/rearsuspension.php
you have stock wheels and tires?
Race Director
Joined: Oct 2000
Posts: 12,681
Likes: 3,134
From: Shamong, NJ
I think the stock rear spring rate, with base suspension, was 315lb. The 355lb spring was more like what was used with the FE7 Gymkhana Suspension.
What you're experiencing is pretty typical, with new aftermarket springs. It seems that most new springs, will cause Corvettes to sit up high. With time, and a few hundred miles, they'll usually settle down to a more normal stance.
The stock spring bolts are 6", and the long ones are 8, but there are also 10" bolts available. They're sold for lowering 84-96's, and are really a little too long for a 63-82. Still, some people have used them temporarily, till their new spring settled, or by cutting them down to about 9".
I'd suggest living with it for a few months, and if it's still sitting too high after 500 miles, then I'd try something else.
What you're experiencing is pretty typical, with new aftermarket springs. It seems that most new springs, will cause Corvettes to sit up high. With time, and a few hundred miles, they'll usually settle down to a more normal stance.
The stock spring bolts are 6", and the long ones are 8, but there are also 10" bolts available. They're sold for lowering 84-96's, and are really a little too long for a 63-82. Still, some people have used them temporarily, till their new spring settled, or by cutting them down to about 9".
I'd suggest living with it for a few months, and if it's still sitting too high after 500 miles, then I'd try something else.
Thread Starter
Melting Slicks
Joined: Jun 2011
Posts: 2,096
Likes: 15
I think the stock rear spring rate, with base suspension, was 315lb. The 355lb spring was more like what was used with the FE7 Gymkhana Suspension.
What you're experiencing is pretty typical, with new aftermarket springs. It seems that most new springs, will cause Corvettes to sit up high. With time, and a few hundred miles, they'll usually settle down to a more normal stance.
The stock spring bolts are 6", and the long ones are 8, but there are also 10" bolts available. They're sold for lowering 84-96's, and are really a little too long for a 63-82. Still, some people have used them temporarily, till their new spring settled, or by cutting them down to about 9".
I'd suggest living with it for a few months, and if it's still sitting too high after 500 miles, then I'd try something else.
What you're experiencing is pretty typical, with new aftermarket springs. It seems that most new springs, will cause Corvettes to sit up high. With time, and a few hundred miles, they'll usually settle down to a more normal stance.
The stock spring bolts are 6", and the long ones are 8, but there are also 10" bolts available. They're sold for lowering 84-96's, and are really a little too long for a 63-82. Still, some people have used them temporarily, till their new spring settled, or by cutting them down to about 9".
I'd suggest living with it for a few months, and if it's still sitting too high after 500 miles, then I'd try something else.
Thread Starter
Melting Slicks
Joined: Jun 2011
Posts: 2,096
Likes: 15
from what I can see the original was 260 but the softest composite for 82 is 345
http://www.duntovmotors.com/rearsuspension.php
you have stock wheels and tires?
http://www.duntovmotors.com/rearsuspension.php
you have stock wheels and tires?
Race Director
Joined: Oct 2000
Posts: 12,681
Likes: 3,134
From: Shamong, NJ
GM doesn't show a spring's rate, in the parts book. The correct spring needed for a car, was based on calculations from a chart in the parts book. The chart listed a base sprung rate for the front and rear of the car, the sprung rate of various options, and then the correct spring needed was determined by the total front or rear sprung weight. Unfortunately, the parts book doesn't list the spring's actual rate.
As I said in my previous post, I think the base spring was rated at about 315lb, while the Gymkhana spring is rated around 355lb. No matter what the spring rate was though, when factory installed, both the base and Gymkhana rear springs, left the factory with the same ride height. Generally, ride height is determined by spring arc, spring height, number of coils, etc., not what the spring is rated at.
Thread Starter
Melting Slicks
Joined: Jun 2011
Posts: 2,096
Likes: 15
Ok thanks for clearing that up for me. But why would I have to install 10" bolts to get the rear to sit lower. Something has to be off somewhere. I have 8" bolts and still has a 3-4" gap between the tire and wheel well.
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Melting Slicks
Joined: Jun 2003
Posts: 2,802
Likes: 241
From: Niles, MI
When I first bought my 82 I had to replace the rear leaf spring because it was cracked but in doing so I had not researched exactly what was needed. I purchased the 355lb spring and the rear has sat up ever since. I eventually changed out the bolts for longer ones and still can get the *** end to come down. So does anyone know exactly what spring I needed? Is that the right one or should have I bought the softer one? I have about 3.5-4" of gap from the top of the tire to the wheel lip. This car has base suspension.
Do yourself a favor and get a VBP spring and your ride height problems will be over.
Thread Starter
Melting Slicks
Joined: Jun 2011
Posts: 2,096
Likes: 15
I believe a 355 lb spring is the TRW style spring made by Muskegan Brake. If that's what you have, the best thing to do is take it off and throw it in the trash. Its a common problem with the TRW style springs. Muskegan Brake is aware of the problem but won't do anything about it.
Do yourself a favor and get a VBP spring and your ride height problems will be over.
Do yourself a favor and get a VBP spring and your ride height problems will be over.
Melting Slicks
Joined: Jun 2003
Posts: 2,802
Likes: 241
From: Niles, MI
Rear fiberglass spring pics
Ride height
Getting back to stock ride height
TRW mono spring and ride height
Thread Starter
Melting Slicks
Joined: Jun 2011
Posts: 2,096
Likes: 15
Here's a few threads that confirm TRW springs are junk.
Rear fiberglass spring pics
Ride height
Getting back to stock ride height
TRW mono spring and ride height
Rear fiberglass spring pics
Ride height
Getting back to stock ride height
TRW mono spring and ride height
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,118
From: Crossville TN
There is nothing functionally wrong with the TRW springs. But, they are not 'shaped' to put the car at the correct ride height, depending on the spring you select. The VBP springs are correctly made, I believe.
If you stick a high spring-rate TRW spring in your car, you will then need to lower your rear end to correct for this problem. That is done by installing LONGER bolts in the spring shackles [usually 8 inch long bolts]. This change is not inexpensive and it is a bit of trouble to make the change. Easier to get a VBP spring, if you don't already have one.
If you want a very firm ride or are going to road race the car, get the stiffer spring (360#). Otherwise, the 330# or the 315# spring will do just fine. Smoother ride with softer spring. The stock springs on the '82 were 250# or so.
If you stick a high spring-rate TRW spring in your car, you will then need to lower your rear end to correct for this problem. That is done by installing LONGER bolts in the spring shackles [usually 8 inch long bolts]. This change is not inexpensive and it is a bit of trouble to make the change. Easier to get a VBP spring, if you don't already have one.
If you want a very firm ride or are going to road race the car, get the stiffer spring (360#). Otherwise, the 330# or the 315# spring will do just fine. Smoother ride with softer spring. The stock springs on the '82 were 250# or so.
Thread Starter
Melting Slicks
Joined: Jun 2011
Posts: 2,096
Likes: 15
There is nothing functionally wrong with the TRW springs. But, they are not 'shaped' to put the car at the correct ride height, depending on the spring you select. The VBP springs are correctly made, I believe.
If you stick a high spring-rate TRW spring in your car, you will then need to lower your rear end to correct for this problem. That is done by installing LONGER bolts in the spring shackles [usually 8 inch long bolts]. This change is not inexpensive and it is a bit of trouble to make the change. Easier to get a VBP spring, if you don't already have one.
If you want a very firm ride or are going to road race the car, get the stiffer spring (360#). Otherwise, the 330# or the 315# spring will do just fine. Smoother ride with softer spring. The stock springs on the '82 were 250# or so.
If you stick a high spring-rate TRW spring in your car, you will then need to lower your rear end to correct for this problem. That is done by installing LONGER bolts in the spring shackles [usually 8 inch long bolts]. This change is not inexpensive and it is a bit of trouble to make the change. Easier to get a VBP spring, if you don't already have one.
If you want a very firm ride or are going to road race the car, get the stiffer spring (360#). Otherwise, the 330# or the 315# spring will do just fine. Smoother ride with softer spring. The stock springs on the '82 were 250# or so.
