ZR-1 Net Registry Forums  

Go Back   ZR-1 Net Registry Forums > C4 ZR-1 > C4 ZR-1 Technical Postings

Reply
 
Thread Tools Display Modes
Old 07-20-2021   #1
Erik
 
Join Date: Nov 2016
Location: New Brunswick
Posts: 961
Default Cutting Rubber Spacers On 1992+ Front Springs - How Much

I'm about to swap the springs in my 1990, to the softer 1992+ springs, with the correct Bilstein shocks and controller. As I understand the front springs got added spacers in 1992 to raise the ride height with the softer springs, and I'd like to keep my ride height looking original, how much should I trim the front spacers by? Seems one gent on here cut them all off, and the result was not enough ground clearance.

So how much is the right amount?
__________________
1990 ZR-1 # 996

"All Corvettes are red. The rest are mistakes." - John Heinricy
Erik is offline   Reply With Quote
Old 07-20-2021   #2
secondchance
 
Join Date: Aug 2006
Location: McLean, VA
Posts: 3,723
Default Re: Cutting Rubber Spacers On 1992+ Front Springs - How Much

I?m not sure whether the spring and shock absorber change occurred starting in 92 or 93.
My 94 (definitely with softer springs) had same rubber/metal plate bumpers inboard for mounting and had rubber pucks where it sits on top of lower A arms. What I did was cut off outboard rubber pucks resulting in toughly 1/2? drop. If you do not see pucks at both ends of the front spring, suspect transition happened in 93.
secondchance is offline   Reply With Quote
Old 07-20-2021   #3
Erik
 
Join Date: Nov 2016
Location: New Brunswick
Posts: 961
Default Re: Cutting Rubber Spacers On 1992+ Front Springs - How Much

Quote:
Originally Posted by secondchance View Post
I?m not sure whether the spring and shock absorber change occurred starting in 92 or 93.
My 94 (definitely with softer springs) had same rubber/metal plate bumpers inboard for mounting and had rubber pucks where it sits on top of lower A arms. What I did was cut off outboard rubber pucks resulting in toughly 1/2? drop. If you do not see pucks at both ends of the front spring, suspect transition happened in 93.
I *Thought* it was 1992, but it could be 1993. Anyhow, the ones I have are definitely the softer spring like yours.

SO the rubber pucks should be about 1/2 and inch in height? I'd go take a look, but it is dark out!
__________________
1990 ZR-1 # 996

"All Corvettes are red. The rest are mistakes." - John Heinricy
Erik is offline   Reply With Quote
Old 07-21-2021   #4
Erik
 
Join Date: Nov 2016
Location: New Brunswick
Posts: 961
Default Re: Cutting Rubber Spacers On 1992+ Front Springs - How Much

And here are my springs. How much should be cut and from where exactly?
__________________
1990 ZR-1 # 996

"All Corvettes are red. The rest are mistakes." - John Heinricy
Erik is offline   Reply With Quote
Old 07-21-2021   #5
secondchance
 
Join Date: Aug 2006
Location: McLean, VA
Posts: 3,723
Default Re: Cutting Rubber Spacers On 1992+ Front Springs - How Much

Quote:
Originally Posted by Erik View Post
And here are my springs. How much should be cut and from where exactly?
Front spring I believe is from later cars judging by puck at the tips. At least based on my observation, all 90s and 91s I have seen had flat plates at the tip.
What I did was cut off pucks at both ends. That dropped the front height by about 1/2?. With both ends trimmed, angled approach allows me to avoid scraping of front air dam (I have M1 prowler) over rain gutters and steep drive ways as long as I keep my speed reasonable.
If you want to lower more, you need to trim the top of two mounting points. By doing so, you will have to approach rain gutters and steep driveways with more caution.
I noticed that most cars that had polyurethane wedges, when springs were removed, we discovered polyurethane wedges were typically ground off and gone.
I have not tried but partial trimming of rubber mounting points and reattaching of steel plates using high strength adhesive such as contact cement may survive better than polyurethane wedge.
secondchance is offline   Reply With Quote
Old 07-22-2021   #6
Erik
 
Join Date: Nov 2016
Location: New Brunswick
Posts: 961
Default Re: Cutting Rubber Spacers On 1992+ Front Springs - How Much

Quote:
Originally Posted by secondchance View Post
Front spring I believe is from later cars judging by puck at the tips. At least based on my observation, all 90s and 91s I have seen had flat plates at the tip.
What I did was cut off pucks at both ends. That dropped the front height by about 1/2?. With both ends trimmed, angled approach allows me to avoid scraping of front air dam (I have M1 prowler) over rain gutters and steep drive ways as long as I keep my speed reasonable.
If you want to lower more, you need to trim the top of two mounting points. By doing so, you will have to approach rain gutters and steep driveways with more caution.
I noticed that most cars that had polyurethane wedges, when springs were removed, we discovered polyurethane wedges were typically ground off and gone.
I have not tried but partial trimming of rubber mounting points and reattaching of steel plates using high strength adhesive such as contact cement may survive better than polyurethane wedge.
So, just the pucks at the ends need to be trimmed. Got it. I don't really want to lower it, but just keep it about the same as it is.

What are these polyurethane wedges? This is something the factory fitted? What do they do?

Thanks for the info.
__________________
1990 ZR-1 # 996

"All Corvettes are red. The rest are mistakes." - John Heinricy
Erik is offline   Reply With Quote
Old 07-22-2021   #7
secondchance
 
Join Date: Aug 2006
Location: McLean, VA
Posts: 3,723
Default Re: Cutting Rubber Spacers On 1992+ Front Springs - How Much

Quote:
Originally Posted by Erik View Post
So, just the pucks at the ends need to be trimmed. Got it. I don't really want to lower it, but just keep it about the same as it is.

What are these polyurethane wedges? This is something the factory fitted? What do they do?

Thanks for the info.
Polyurethane wedges are sold as spring modification pieces. Cut off rubber bumper mounting pieces and glue polyurethane wedges instead. These are lower profile and used to lower the car.
secondchance is offline   Reply With Quote
Reply


Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -4. The time now is 08:28 PM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Copyright ZR-1 Net Registry 2020