Rear Spring Replacement
Team Owner
Joined: Aug 1999
Posts: 30,995
Likes: 98
From: Ontario
Melting Slicks
Joined: Apr 2001
Posts: 3,399
Likes: 278
From: Olmsted Falls, Ohio
And you MUST use the heat shield, you might be suprised how warm the shield feels after idling the car for 15 minutes.
Melting Slicks
Joined: Apr 2008
Posts: 2,623
Likes: 242
From: Russell Ontario
St. Jude Donor '09
I agree with Paul , I installed quite a few of these and what a difference , on my 80 I got a 360lbs with Munro gas shocks , no need to waste money on expensive stuff if you don't track it . Ron
Advanced
Joined: May 2012
Posts: 58
Likes: 3
From: Clarkston MI
I just got a 72 vette and I'm pretty sure it is need of a rear spring and shocks. So I'm definitely enjoying the thread. How should I go about determining the spring rate I'd like? I'd like it to ride smooth (I live in MI and the roads are Sh&$) However, I always find I push my cars and want performance. 330#?
Thanks
Thanks
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Le Mans Master
Joined: Oct 2007
Posts: 7,445
Likes: 971
From: Tennessee/Rhode Island
78 L-82 4 speed with the OEM gymkhana 7 leaf sport spring and replaced it in 1986 with a VBP 360 mono spring back then with KYB Gas A just shocks-was way too bouncy. In the early 2000's replaced the Gas A Just with Bilstein Heavy Duties-gigantic improvement but still too bouncy for my liking. Sold the bilstein HD's to a forum member with about 2,000 miles on them and replaced them the rears only with Bilstein Sports (30% stiffer than the Hd's) about 5 years ago and the ride is perfect. Recently took a neighbor for a ride who owns a Lexus LS430 and he could not believe how good my car rode for a C3. It really is that good with the 360 spring and the Bilstein Sports. No heat shield except the factory one right under the spring where it mounts to the diff-zero issues. Don't waste your money on KYB's/Monroes/Delcos etc with a mono spring. Go for the Bilsteins!-They will never wear out! Last shock you will ever have to buy. They are that good and worth the money!
I would not use a mono spring rated less than 330 lbs/in-200 is way too soft for these cars and it will ride and handle like a 70's cadillac with that marshmallow spring!
I would not use a mono spring rated less than 330 lbs/in-200 is way too soft for these cars and it will ride and handle like a 70's cadillac with that marshmallow spring!
Last edited by jb78L-82; May 15, 2012 at 06:43 AM.
Advanced
Joined: Dec 2010
Posts: 53
Likes: 0
From: Clearwater FL
78 L-82 4 speed with the OEM gymkhana 7 leaf sport spring and replaced it in 1986 with a VBP 360 mono spring back then with KYB Gas A just shocks-was way too bouncy. In the early 2000's replaced the Gas A Just with Bilstein Heavy Duties-gigantic improvement but still too bouncy for my liking. Sold the bilstein HD's to a forum member with about 2,000 miles on them and replaced them the rears only with Bilstein Sports (30% stiffer than the Hd's) about 5 years ago and the ride is perfect. Recently took a neighbor for a ride who owns a Lexus LS430 and he could not believe how good my car rode for a C3. It really is that good with the 360 spring and the Bilstein Sports. No heat shield except the factory one right under the spring where it mounts to the diff-zero issues. Don't waste your money on KYB's/Monroes/Delcos etc with a mono spring. Go for the Bilsteins!-They will never wear out! Last shock you will ever have to buy. They are that good and worth the money!
I would not use a mono spring rated less than 330 lbs/in-200 is way too soft for these cars and it will ride and handle like a 70's cadillac with that marshmallow spring!
I would not use a mono spring rated less than 330 lbs/in-200 is way too soft for these cars and it will ride and handle like a 70's cadillac with that marshmallow spring!
Advanced
Joined: Apr 2005
Posts: 89
Likes: 5
From: Madison WI
Question for paul 74 and/or others who went with the VBP #330 and the VBP shocks. Did you go with longer spring bolts or stick with the stock length? I remember hearing about the car sitting high after the install. Definately don't want that. I want to maintain current height. I have thought about doing this for a long time, but have not due to those (horror?) stories.
Dale
Dale
Race Director
Joined: Oct 2000
Posts: 17,102
Likes: 7
From: Fair Oaks, OK
Its been a few months, so I hope I remember correctly, but it seems like I ordered the VBP 330lb spring in a "kit" that included all mounting hardware (longer bolts). I have no problems with ride height whatsoever. Also note that my spring bolts don't hang down dangerously close to the rear tires like many of the pictures that we see on here from time to time. My setup looks just like Paul74's picture above.
Racer
Joined: Oct 2004
Posts: 281
Likes: 9
From: New England
I just installed the VBP Performance plus suspension. I called VBP before I ordered my kit and told them that I want my spring rate for just street and I wanted a nice ride. I have the #260 lb rear spring and a #630 front spring. The Performance Plus kit has the adjustable spring rate and works out great with these spring rates for me.
I had the F7 gymkhana suspension from the factory and my new suspension is a bit stiffer than what I had with the F7. Check out my album picture # 12 . The system
Lowered my whole car, front lowered by 6 inches and the rear by 4 inches
VBP can make any rates spring for your needs.
I had the F7 gymkhana suspension from the factory and my new suspension is a bit stiffer than what I had with the F7. Check out my album picture # 12 . The system
Lowered my whole car, front lowered by 6 inches and the rear by 4 inches
VBP can make any rates spring for your needs.
Team Owner
Joined: Aug 1999
Posts: 30,995
Likes: 98
From: Ontario
Question for paul 74 and/or others who went with the VBP #330 and the VBP shocks. Did you go with longer spring bolts or stick with the stock length? I remember hearing about the car sitting high after the install. Definately don't want that. I want to maintain current height. I have thought about doing this for a long time, but have not due to those (horror?) stories.
Dale
Dale
As to ride height I do not see a problem. The 235-60 tires (rather than stock 225-70) do allow for some air to show in the wheel wells but the car looks and drives fine.
Last edited by Paul L; Jul 28, 2012 at 03:13 PM.
Instructor
Joined: Feb 2007
Posts: 114
Likes: 18
From: McKinney TX
When I was younger I had a '63 with standard suspension. A number of my friends had similar C2's. All were real stiff in the rear and we just thought it normal to come to something close to a full stop whenever we crossed railroad tracks. The point is, this was my baseline for Corvette suspension stiffness.
When I got my C3, I was surprised at how much softer was the ride. For me, I preferred stiffer. After some years I replaced the standard steel spring with a VBP 360 mono-leaf. I was familiar with all the posts regarding shock stiffness so I also installed QA-1 adjustables. I set the adjustment at something like 4-5. Way too bouncy! I upped the adjustment to an 8 and it's much better. I've considered taking it up to a 9 but haven't done so.
Recently I was doing some more work on the back end so I replaced the 360 lb spring with a 420 lb spring. No change to the shocks. It doesn't seem much different but I prefer the 420 all the same.
The C3 rides better now than it ever has - much better than stock. I am a big advocate of the mono-leaf spring and as you can tell, I'd err to the stiff side when making a choice.
When I got my C3, I was surprised at how much softer was the ride. For me, I preferred stiffer. After some years I replaced the standard steel spring with a VBP 360 mono-leaf. I was familiar with all the posts regarding shock stiffness so I also installed QA-1 adjustables. I set the adjustment at something like 4-5. Way too bouncy! I upped the adjustment to an 8 and it's much better. I've considered taking it up to a 9 but haven't done so.
Recently I was doing some more work on the back end so I replaced the 360 lb spring with a 420 lb spring. No change to the shocks. It doesn't seem much different but I prefer the 420 all the same.
The C3 rides better now than it ever has - much better than stock. I am a big advocate of the mono-leaf spring and as you can tell, I'd err to the stiff side when making a choice.
Pro
Joined: Feb 2002
Posts: 709
Likes: 10
From: Carlsbad CA
Installation note: do NOT torque down the four bolts holding spring to differential until you have the weight of the car on the spring. You can crack the differential housing if you tighten the bolts with the wheels off the ground.
Le Mans Master
Joined: Apr 2007
Posts: 7,353
Likes: 72
From: Graceland in a Not Correctly Restored Stingray
Since spring rates affect balance as well as bars, if you are just guessing between two rear springs IMCO the prudent move would be erring with the softer one. This may not seem important to anyone who doesn't ever plan on pushing the limits, but you never know when an unexpected situation could put you there. And, that's no time to find out whether or not you've taken rear roll stiffness too far and created an oversteer characteristic. My $.02
Le Mans Master
Joined: Oct 2007
Posts: 7,445
Likes: 971
From: Tennessee/Rhode Island
The biggest problem with the C3's suspension is that it has way too much play in its design even with rubber components that are new. I have spent 25 years experimenting with many different setups and have concluded that you should do everything you can to tighten up the suspension components.
C3 member, Karol, recently rode in my 78 L-82 which originally had the gymkhana suspension and Karol's 78 L-82 does not have the sport suspension nor a composite spring (among many other differences) and he could not believe how much better my car rode, steered, and handled than his.
Last edited by jb78L-82; Jul 29, 2012 at 08:24 PM.
Racer
Joined: Dec 2011
Posts: 284
Likes: 4
From: Philadelphia Pennsylvania
I just put a #300 vbp spring on and bilstein HD shocks, which should be softer than the #330-360 and bilstein Sport shocks that seems to be common here. I could tell you how it rides if only I could get my brakes bled properly so I can drive the damned thing. Argh.