C3 Tech/Performance V8 Technical Info, Internal Engine, External Engine, Basic Tech and Maintenance for the C3 Corvette
Sponsored by:
Sponsored by:

Composite rear spring

Thread Tools
 
Search this Thread
 
Old Jun 4, 2016 | 02:54 AM
  #1  
mrichi's Avatar
mrichi
Thread Starter
Instructor
10 Year Member
 
Joined: Jan 2012
Posts: 216
Likes: 16
From: Tanunda South Australia
Default Composite rear spring

Hi I've installed a VB&P 420 composite rear spring ,but I am struggling to get enough ride height into the rear end , even with the spring bolts screwed right up the height from the ground to the lip of the wheel arch is 68cm not sure what I am doing wrong

Does anyone have a photo of a VB&P composite rear spring installed on their car
Reply
Old Jun 4, 2016 | 07:42 AM
  #2  
leadfoot4's Avatar
leadfoot4
Team Owner
25 Year Member
Active Streak: 60 Days
Active Streak: 90 Days
Community Builder
 
Joined: May 2001
Posts: 87,367
Likes: 1,593
From: Western NY
Default

Originally Posted by mrichi
Hi I've installed a VB&P 420 composite rear spring ,but I am struggling to get enough ride height into the rear end , even with the spring bolts screwed right up the height from the ground to the lip of the wheel arch is 68cm not sure what I am doing wrong

Does anyone have a photo of a VB&P composite rear spring installed on their car
How long are your spring bolts? IIRC, the stock length is around 8" in length, and guys wanting to lower their cars, run 10" long bolts.
Reply
Old Jun 4, 2016 | 09:14 AM
  #3  
Metalhead140's Avatar
Metalhead140
Drifting
 
Joined: Aug 2015
Posts: 1,939
Likes: 477
From: NSW, Australia
C3 of Year Finalist (track prepared) 2019
Default

Your might be thinking c4? Stock c3 bolts are ~6", and 8" bolts are normally used for lowering, occasionally 10" but they may have clearance issues.
Reply
Old Jun 4, 2016 | 01:19 PM
  #4  
C3 Stroker's Avatar
C3 Stroker
Safety Car
20 Year Member
Liked
Loved
Community Favorite
 
Joined: Oct 2004
Posts: 3,926
Likes: 739
From: Youngstown Ohio
Default

Originally Posted by mrichi
Hi I've installed a VB&P 420 composite rear spring ,but I am struggling to get enough ride height into the rear end , even with the spring bolts screwed right up the height from the ground to the lip of the wheel arch is 68cm not sure what I am doing wrong

Does anyone have a photo of a VB&P composite rear spring installed on their car
I have the VBP 380 composite rear spring..... see my sig picture...
Reply
Old Jun 4, 2016 | 01:44 PM
  #5  
Paul L's Avatar
Paul L
Team Owner
15 Year Member
 
Joined: Aug 1999
Posts: 30,995
Likes: 99
From: Ontario
Default

Here is a #330. The stock bolts are just over 6". Those in the pic are 8".

"Spring bolts are screwed right up." Do you mean that the nuts on the bolts are at the top of the thread travel?

Reply
Old Jun 4, 2016 | 08:48 PM
  #6  
mrichi's Avatar
mrichi
Thread Starter
Instructor
10 Year Member
 
Joined: Jan 2012
Posts: 216
Likes: 16
From: Tanunda South Australia
Default

Originally Posted by paul 74
Here is a #330. The stock bolts are just over 6". Those in the pic are 8".

"Spring bolts are screwed right up." Do you mean that the nuts on the bolts are at the top of the thread travel?

Yes i've had to screw the nut to the top of the thread travel and even doing that the rear of the car is only just high enough
Reply
Old Jun 5, 2016 | 12:19 AM
  #7  
CheezMoe's Avatar
CheezMoe
Melting Slicks
10 Year Member
 
Joined: Mar 2006
Posts: 3,456
Likes: 102
From: Piedmont Va
St. Jude Donor '11-'12-'13,'19-'20
Default

Sounds to me like maybe the spring is upside down. Most complain they can't get low enough. Paul's pic is correct with 8" bolts mine looks the about the same and have 28 1/2" at center wheel well.

Good luck!
Reply
Old Jun 5, 2016 | 12:35 AM
  #8  
TOM B1's Avatar
TOM B1
Burning Brakes
15 Year Member
 
Joined: Oct 2003
Posts: 836
Likes: 26
From: Harrisburg Pa
Default

post a pic of your spring. some composites require a thick spacer between the spring and rear end mount to raise the ride height.
Reply
Corvette Stories

The Best of Corvette for Corvette Enthusiasts

story-0

10 Ugly Corvettes That We Still Kinda Love

 Joe Kucinski
story-1

Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer

 Brett Foote
story-2

10 Things Every Corvette Owner Needs (2026 Edition)

 Michael S. Palmer
story-3

8 Most "Only Corvette Owners Understand" Quirks and Problems

 Pouria Savadkouei
story-4

10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years

 Joe Kucinski
story-5

How Much Horsepower Every Corvette Engine "LOST" in 1972

 Joe Kucinski
story-6

Top 10 DOs and DON'Ts for Protecting Your Convertible Top!

 Michael S. Palmer
story-7

Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!

 Joe Kucinski
story-8

150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter

 Joe Kucinski
story-9

8 Coolest Corvette Pace Cars (and Replicas) of All Time

 Verdad Gallardo
Old Jun 5, 2016 | 08:48 AM
  #9  
leadfoot4's Avatar
leadfoot4
Team Owner
25 Year Member
Active Streak: 60 Days
Active Streak: 90 Days
Community Builder
 
Joined: May 2001
Posts: 87,367
Likes: 1,593
From: Western NY
Default

Originally Posted by Metalhead140
Your might be thinking c4? Stock c3 bolts are ~6", and 8" bolts are normally used for lowering, occasionally 10" but they may have clearance issues.
Yeah, maybe....it's been a while since I've worked on a C-3.
Reply
Old Jun 9, 2016 | 07:36 AM
  #10  
mrichi's Avatar
mrichi
Thread Starter
Instructor
10 Year Member
 
Joined: Jan 2012
Posts: 216
Likes: 16
From: Tanunda South Australia
Default

Finally have photos the spring is a new VB&P 420 car is a 79 Corvette with a 454 big block .As the photo shows ive had to screw the spring bolt nut almost right up to the top of the thread to get a reasonable ride height . I can't work out whats wrong , should the spring be curved up at the ends as the photo shows hotos
Reply
Old Jun 9, 2016 | 08:00 AM
  #11  
jkippin's Avatar
jkippin
Burning Brakes
Supporting Lifetime Gold
10 Year Member
Liked
Loved
Community Favorite
 
Joined: Feb 2014
Posts: 1,045
Likes: 226
From: Cape Neddick Maine
2020 C3 of the Year Finalist - Modified
Default

that spring looks to be installed correctly. Looking at the photo is it a shadow or could the spring be cracked in the middle of the center mount?
Reply
Old Jun 9, 2016 | 08:40 AM
  #12  
mrichi's Avatar
mrichi
Thread Starter
Instructor
10 Year Member
 
Joined: Jan 2012
Posts: 216
Likes: 16
From: Tanunda South Australia
Default

Originally Posted by jkippin
that spring looks to be installed correctly. Looking at the photo is it a shadow or could the spring be cracked in the middle of the center mount?
I think it's just some sticky material from packaging ,but I will have a closer look at it thank you
Reply
Old Jun 9, 2016 | 09:55 AM
  #13  
Dodosmike's Avatar
Dodosmike
Le Mans Master
15 Year Member
Liked
Loved
Community Favorite
 
Joined: Apr 2008
Posts: 9,434
Likes: 239
From: Powassan ON
Default

Looks right to me as well. I'll try and find some pics of my '78 rear spring install to compare.

The reason the spring looks like its "up" at the ends is because the nuts on the spring bolt are pushing it up, as you stated earlier.

Was the car ever hit in the back end?
How long are the bolts overall?
Are the half shafts fairly level or are they noticeably higher on either end?
Is the spring "new" or did you buy a used spring? Could it be possibly mis-labeled and not a 420?

edit:
Still on the wrecked parts car before I put it on the driver car.



I don't have a pic of mount in the middle for some reason.

Last edited by Dodosmike; Jun 9, 2016 at 10:03 AM.
Reply
Old Jun 9, 2016 | 10:21 AM
  #14  
jkippin's Avatar
jkippin
Burning Brakes
Supporting Lifetime Gold
10 Year Member
Liked
Loved
Community Favorite
 
Joined: Feb 2014
Posts: 1,045
Likes: 226
From: Cape Neddick Maine
2020 C3 of the Year Finalist - Modified
Default

If I remember correctly VBP gives you a rough pre adjustment measurement of 1.25 inches of thread showing on the supplied bolts with new springs. You are clearly beyond that.
Here is a dual mount VBP spring but the threads on the bolts are in the same location as to when it had the single mount spring. Rear height is 27.0
Name:  IMG_1836.JPG
Views: 1902
Size:  1.34 MB

Name:  IMG_1837.JPG
Views: 1966
Size:  1.58 MB

Name:  IMG_1838.JPG
Views: 1361
Size:  1.55 MB
Reply
Old Jun 9, 2016 | 11:40 AM
  #15  
wendellp601's Avatar
wendellp601
Safety Car
10 Year Member
Community Builder
Community Influencer
Photoriffic
 
Joined: Apr 2015
Posts: 4,887
Likes: 202
From: Jackson MS
Default

Originally Posted by mrichi
I think it's just some sticky material from packaging ,but I will have a closer look at it thank you
When I compare your photos to the one that Paul74 posted, there seems to be a difference in the way your spring tapers down at the end. His looks like the taper is on top of the spring, and yours appears to have the taper on the bottom.
Reply
Old Jun 9, 2016 | 11:58 AM
  #16  
jkippin's Avatar
jkippin
Burning Brakes
Supporting Lifetime Gold
10 Year Member
Liked
Loved
Community Favorite
 
Joined: Feb 2014
Posts: 1,045
Likes: 226
From: Cape Neddick Maine
2020 C3 of the Year Finalist - Modified
Default

pull the spring out and check it. The curved part should be down. the rubber mount should be on the top ,against the differential mounting point and the metal tips on the end of the spring should be on the bottom of the spring.
If the spring is brand new maybe someone assembled it upside down by mistake.
Reply
Old Jun 9, 2016 | 01:50 PM
  #17  
Neil B's Avatar
Neil B
Drifting
10 Year Member
 
Joined: Jun 2008
Posts: 1,565
Likes: 111
Default

This does not look right to me at all. The spring should be tapering down, not up.

Reply

Get notified of new replies

To Composite rear spring

Old Jun 9, 2016 | 01:55 PM
  #18  
claysmoker's Avatar
claysmoker
Race Director
20 Year Member
Active Streak: 30 Days
Liked
Loved
 
Joined: Dec 2004
Posts: 10,332
Likes: 63
From: PARADISE
St. Jude Donor '09-'11-'12-'13-'14
Default

Flip the spring over.
Reply
Old Jun 9, 2016 | 02:02 PM
  #19  
keithinspace's Avatar
keithinspace
Drifting
10 Year Member
 
Joined: Jan 2012
Posts: 1,908
Likes: 129
From: Fredericksburg Virginia
Default

You can't just 'flip the spring over' since the metal stuff is installed by VB&P and it can only be installed one way.

THAT SAID, something looks totally wrong about that picture. No way in the world should it be that close to the trailing arm. There needs to be some 'bolt' there to allow things to move around as the suspension flexes. And I don't like how the end of the spring is pointed to the sky. It should be flat or pointed slightly down.

Either you got a totally bum spring (something jacked inside it) or VB&P installed the metal widgets at the end of the spring upside down.

Whatever the case, that isn't right. I would not drive my car like that.
Reply
Old Jun 9, 2016 | 02:15 PM
  #20  
7t9l82's Avatar
7t9l82
Le Mans Master
15 Year Member
Conversation Starter
Photogenic
Community Favorite
 
Joined: Oct 2010
Posts: 6,937
Likes: 848
From: melbourne florida
2023 C3 of the Year Finalist - Modified
Default

Sure looks inverted to me. I think those ends bolt on call VBP and ask if that's the case.
Reply



All times are GMT -4. The time now is 03:20 PM.

story-0
10 Ugly Corvettes That We Still Kinda Love

Slideshow: 10 ugly Corvettes that we still kinda love.

By Joe Kucinski | 2026-06-03 10:34:17


VIEW MORE
story-1
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer

A lot of money has changed hands at the online auction house over the years.

By Brett Foote | 2026-06-03 10:21:50


VIEW MORE
story-2
10 Things Every Corvette Owner Needs (2026 Edition)

Slideshow: 10 great gifts Corvette enthusiasts actually want for Father's Day!

By Michael S. Palmer | 2026-06-03 15:43:40


VIEW MORE
story-3
8 Most "Only Corvette Owners Understand" Quirks and Problems

Slideshow: These are the quirks, annoyances, and oddly lovable problems that every Corvette owner eventually learns to live with.

By Pouria Savadkouei | 2026-05-28 09:31:39


VIEW MORE
story-4
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years

Slideshow: 10 reasons why the C6 Z06 is still a performance benchmark after 20 years.

By Joe Kucinski | 2026-05-27 17:20:09


VIEW MORE
story-5
How Much Horsepower Every Corvette Engine "LOST" in 1972

Slideshow: How much horsepower every Corvette engine lost in 1972.

By Joe Kucinski | 2026-05-27 16:54:53


VIEW MORE
story-6
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!

Slideshow: How to Protect A Convertible Top: 10 DOs & DON'Ts

By Michael S. Palmer | 2026-04-03 00:00:00


VIEW MORE
story-7
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!

Slideshow: The 10 most explosive Corvettes ever built based on power-to-weight ratio.

By Joe Kucinski | 2026-05-20 07:23:03


VIEW MORE
story-8
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter

Slideshow: From C1 to C8 we compare every Corvette generation by the numbers.

By Joe Kucinski | 2026-05-12 16:54:12


VIEW MORE
story-9
8 Coolest Corvette Pace Cars (and Replicas) of All Time

Slideshow: Some Corvette pace cars became collectible legends, while others perfectly captured the look and attitude of their era.

By Verdad Gallardo | 2026-05-11 09:50:51


VIEW MORE