Dropping a z one inch

[viper107]

Anybody drop their z and keep the springs in the car? If so what did you use front and rear and how does it ride now?

[1991 Corvette ZR-1]

The rear is not a problem so much as the front. To drop the front, unless a new way has been discovered, the top part of the cushion on both sides of the spring has to be removed and replaced with acquired lowering wedges for a parts supplier. They are made of urethane and pyramid shaped. The problem some have encountered with this is using a specific adhesive to fix them to the spring. The spring tends to dislodge them and spit them out. I have not heard of anyone finding an adhesive that was a permanent fool proof way to keep the wedges bonded to the spring.

It may have something to do with the actual design of the wedges. The factory cushion has a pivoting assembly inside the rubber on top of the spring, allowing the rubber to flex and move as the spring flexes. The wedge is solid and stationary. The side with the cured adhesive takes the brunt of the flexing of the spring and the weight of the car and gets spit out.

[DRM500RUBYZR-1]

Originally Posted by 1991 Corvette ZR-1

The rear is not a problem so much as the front. To drop the front, unless a new way has been discovered, the top part of the cushion on both sides of the spring has to be removed and replaced with acquired lowering wedges for a parts supplier. They are made of urethane and pyramid shaped. The problem some have encountered with this is using a specific adhesive to fix them to the spring. The spring tends to dislodge them and spit them out. I have not heard of anyone finding an adhesive that was a permanent fool proof way to keep the wedges bonded to the spring.

It may have something to do with the actual design of the wedges. The factory cushion has a pivoting assembly inside the rubber on top of the spring, allowing the rubber to flex and move as the spring flexes. The wedge is solid and stationary. The side with the cured adhesive takes the brunt of the flexing of the spring and the weight of the car and gets spit out.

Your explanation of your experiences with the front spring is identical to our experience in the shop.
We no longer even attempt this.
Often, aftermarket springs present the same issue, with failing cushions.

If it must go down, coil overs provide full adjustability to set it where you want it, and or change it whenever.
Having had them on my ZR-1 for 25 years now I love the ride and handling and one day might start tinkering with the ride height.

Of course there are many ways to do anything, which all might also work, but empirically, 1991's post mirrored our results.
Many members have lowered cars.
How did you get it done?

Marty

[Z51JEFF]

Years ago VP&P made an adjustable front spring that I've got but from what I understand they are no longer in business. If I had to replace the spring I'd look into a set of Viking coil overs.

[conesare2seconds]

Originally Posted by Z51JEFF

[url=https://postimg.cc/4HtzThSz]
Years ago VP&P made an adjustable front spring that I've got but from what I understand they are no longer in business. If I had to replace the spring I'd look into a set of Viking coil overs.

I?ve been on the lookout for a VB&P adjustable front spring. Someone on the big forum posted that VanSteel was going to re-start production but I gave them a call and was told that isn?t the case. Hard to believe no one bought the rights to manufacture them but I guess the customer pool has dwindled over the years. I?d love to find one. I wish I?d known VB&P was closing down. Does anyone know the story? Retirement?

[Z51JEFF]

Originally Posted by conesare2seconds

I?ve been on the lookout for a VB&P adjustable front spring. Someone on the big forum posted that VanSteel was going to re-start production but I gave them a call and was told that isn?t the case. Hard to believe no one bought the rights to manufacture them but I guess the customer pool has dwindled over the years. I?d love to find one. I wish I?d known VB&P was closing down. Does anyone know the story? Retirement?

It wouldn't be difficult to make. The spring is just a composite spring with a nutcert in a drilled hole. The adjuster wouldnt be easy to duplicate now that I've seen how everything was made. I've modified the setup I have so I know it can be done.

[viper107]

ok thanks guys, i guess its coilover time from drm

[Jagdpanzer]

On this previous post from April 2020 I discuss ditching failed urethane wedges for hard neoprene strips (from McMaster-Carr) which I bonded to the spring with 3M Super weather strip cement.
http://www.zr1.net/forum/showthread....light=neoprene

So far no issues to report.

Sent from my iPhone using ZR-1 Net Registry

[Jcsws6]

I've got a few of mine lowered on bolts and shaved cushions. The trick I found was the cushion needs to be shaved and grooved, not removed.

[conesare2seconds]

Hmm. I haven?t seen one in a while, thought it was more complicated. If it wouldn?t be hard, maybe it would make a good HOTB how-to.