Do not modify the composite spring.
Shorten a Composite rear spring?
Thread Starter
Heel & Toe
Joined: Sep 2008
Posts: 22
Likes: 0
From: Växjö kronoberg
Shorten a Composite rear spring?
I have VBP´s 420 Composite rear leaf spring.
Can I shorten it myself?
Just stick it off about 1" on each side and drill a new hole for the bolt, or will the composite material crack?
I will get my boss 338 wheels 18*9.5 with 285/40-18 tires soon, and I am guessing that shorten the rear spring with 10" bolts will be necessary..
Can I shorten it myself?
Just stick it off about 1" on each side and drill a new hole for the bolt, or will the composite material crack?
I will get my boss 338 wheels 18*9.5 with 285/40-18 tires soon, and I am guessing that shorten the rear spring with 10" bolts will be necessary..
Tech Contributor
Joined: Jun 2004
Posts: 20,910
Likes: 962
From: I tend to be leery of any guy who doesn't own a chainsaw or a handgun.
I narrowed mine. The car is still apart, so no miles on it yet, but the end terminations look the same now as they did before the modification.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Le Mans Master
Joined: Apr 2000
Posts: 5,202
Likes: 10
From: cincinnati ohio
St. Jude Donor '09
Tech Contributor
Joined: Jun 2004
Posts: 20,910
Likes: 962
From: I tend to be leery of any guy who doesn't own a chainsaw or a handgun.
Race Director
Joined: May 2005
Posts: 10,674
Likes: 122
From: Millington Illinois
St. Jude Donor '08-'09
Or you could buy this for $150:
http://forums.corvetteforum.com/c3-p...te-spring.html
And sell yours.
http://forums.corvetteforum.com/c3-p...te-spring.html
And sell yours.
Team Owner
Joined: Jul 1999
Posts: 65,492
Likes: 230
From: Orange Park Florida
I have VBP´s 420 Composite rear leaf spring.
Can I shorten it myself?
Just stick it off about 1" on each side and drill a new hole for the bolt, or will the composite material crack?
I will get my boss 338 wheels 18*9.5 with 285/40-18 tires soon, and I am guessing that shorten the rear spring with 10" bolts will be necessary..
Can I shorten it myself?
Just stick it off about 1" on each side and drill a new hole for the bolt, or will the composite material crack?
I will get my boss 338 wheels 18*9.5 with 285/40-18 tires soon, and I am guessing that shorten the rear spring with 10" bolts will be necessary..
Drifting
Joined: Nov 2004
Posts: 1,631
Likes: 293
2020 C3 of the Year Finalist - Modified
Bringing it back!
What's the most someone has shortened a composite rear spring? I ordered mine shortened (1/2"on each side if remember right) and it's still pretty close to the rear tire. I was thinking of maybe another 1/4" - 1/2"on each side to ease my mind about my tires rubbing in turns. I'm using the 10"lowering bolts in the rear.
Ryan
Ryan
Tech Contributor
Joined: Jun 2004
Posts: 20,910
Likes: 962
From: I tend to be leery of any guy who doesn't own a chainsaw or a handgun.
Update: Been running my car on autocross and track days since completing the build two years ago, and the spring is doing just fine.
Safety Car
Joined: Nov 2008
Posts: 3,720
Likes: 554
From: Seattle Washington
If you shorten the Spring it changes the Bolt Angles unless You move the Mount on the Trailing Arms. I found out the hard way that this is unessisary as the Spring will probably fit up inside the Rims on 17" or larger Rims anyway. What I do do tho is Cut off the Spring Corner on the Aft side where it is closest to the Rim. The metal Bracket that is on the Spring ends has a Sharp Corner and it acts like a Lathe Bit and will ruin a Wheel in an instant if contact happens. So I just Cut it off, never had a problem. I might remove a 1/2" at a 45 deg angle.
Drifting
Joined: Nov 2004
Posts: 1,631
Likes: 293
2020 C3 of the Year Finalist - Modified
Drifting
Joined: Nov 2004
Posts: 1,631
Likes: 293
2020 C3 of the Year Finalist - Modified
If you shorten the Spring it changes the Bolt Angles unless You move the Mount on the Trailing Arms. I found out the hard way that this is unessisary as the Spring will probably fit up inside the Rims on 17" or larger Rims anyway. What I do do tho is Cut off the Spring Corner on the Aft side where it is closest to the Rim. The metal Bracket that is on the Spring ends has a Sharp Corner and it acts like a Lathe Bit and will ruin a Wheel in an instant if contact happens. So I just Cut it off, never had a problem. I might remove a 1/2" at a 45 deg angle.
My spring won't fit up inside my 18"wheels, maybe because I have ,the car sitting low in the rear. Itd probably run in turns. I understand what you are saying about the position change of the lower bolt with shortening the reat spring. Cutting the corner edges is thought.
Drifting
Joined: Sep 2006
Posts: 1,986
Likes: 21
From: Columbus MN
If you shorten the Spring it changes the Bolt Angles unless You move the Mount on the Trailing Arms. I found out the hard way that this is unessisary as the Spring will probably fit up inside the Rims on 17" or larger Rims anyway. What I do do tho is Cut off the Spring Corner on the Aft side where it is closest to the Rim. The metal Bracket that is on the Spring ends has a Sharp Corner and it acts like a Lathe Bit and will ruin a Wheel in an instant if contact happens. So I just Cut it off, never had a problem. I might remove a 1/2" at a 45 deg angle.
Tech Contributor
Joined: Jun 2004
Posts: 20,910
Likes: 962
From: I tend to be leery of any guy who doesn't own a chainsaw or a handgun.
