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The leaf springs on my car are worn out to the point where my car sits very low (its wide bodied aswell so probably more stress on the springs), i even hit things with my headers sometimes. I was looking at replacing the leaf springs but they're not made anymore. I did see that Vansteel offers new leaf springs but they don't have them in stock and i live in the EU so importing and shipping would be very expensive.
My local garage said it would probably be best to go for coilovers. That would work but i want to maintain the ride control fx functionality of the car.
So i came accross this kit which lets you make coilovers with the fx3 shocks. I was wondering if anyone had done this before and if the kit has everything you need to make it all functional.
Would this kit make the car back to orignal ride height?
Any tips/suggestions?
I did email the company but have gotten no response.
Unusual for the leaf springs to wear out.
I am curious if they were damaged / delaminating.
They dont wear out like truck leaf springs, the only reason I mention this is to be sure the shop
isnt trying to take you for a ride
ive been on here 25 yrs and i dont remember anybody ever complaining that their (transverse) leaf spring had worn out. I have seen others say its delaminating, pieces of it sticking out if damaged, nicked or exposed to harsh chemicals. GM got rid of the fatigue testing machine that tested the c4’s transverse leaf spring bc the machine kept wearing out (the leaf did not) and they got tired of repairing it
if you just got the car, its possible the PO lowered it
All that said, coil overs are a great mod and should be encouraged.
(I personally think the c4 suspension isnt truly independant because of the leaf connecting each side (even though they do have isolators)
Last edited by dizwiz24; Apr 19, 2025 at 06:34 PM.
Yeah, they're 33years old and the car is wide bodied so maybe there's a bit more stress. I've read on some places that it does fatigue in time.
The car could also be lowered, i'm not sure, i got it around 2y ago.
Yes, the DRM kit has everything to keep the FX3 functional. You will need to groove the shocks to accept the metal ring for bottom shock collar. Been plenty of write ups on the forum with them.
Thanks @ChumpVette , So basically just buy the kit, remove the leafspring and install the DRM kit. Do you have any idea about ride height? I'll search for the other posts regarding this kit aswell.
I would think that if you review several threads here, make notes you could fabricate this set-up in your country or very close. Certainly there are vendors that do coil-overs of some sort near you.
Graulus, if that avatar image is your car, it's lowered intentionally - the springs haven't fatigued. O agree with dizwiz (it had to happen sometime!) that fiberglass leaf springs don't wear out unless they are delaminating. You can see that damage if you look at the springs, though. You can probably raise the rear ride height by threading the nuts holding the spring end bushings upward on their bolts. The front was most like lowered with lowering wedges in the center clamps and/or cutting down the pads on the ends of the spring. That's a more difficult job to reverse, but it could be done. This would allow you to keep the FX3 option if you want.
The springs Van Steel is selling are being made in the molds that they bought from Vette Brake Products when VBP went out of business. Back in the day, VBP springs were great. I have no reason to believe these aren't good quality. However, based on info gleaned from another forum member's recent experience combined with knowledge of how spring and wheel rates actually work, it seems that Van Steel doesn't quite understand how these things work. As a result, they are advertising springs stiffer than the OE Challenge Z51 sets as their soft-riding FE1 sets. If you do decide to go this route, let's discuss what they are selling so you can choose an appropriate set. This option lets you keep FX3 as well.
It's worth considering if FX3 is worth keeping, too. Its advantage is adjustable damping rates on the fly, obviously. There is value in that, but the question to consider is: how often do you actually change the settings while driving. Does your use allow for the possibility of stopping the car and taking five minutes to adjust individual damper ***** instead? I ask that because there are some high-quality coilover kits available in the US that have easy-access adjustment ***** on the shock bodies, and I think these kits will provide an overall better experience than the old DRM adapter kit you're looking at. The ones I have in mind are the Viking-based kits by After Dark Speed and the Fox-based kits from Ridetech. Going with these kits would provide you brand new dampers with proper adjustments and much better/newer damping curves than 33-year-old Bilsteins or Delcos (whatever the FX3 option was based on).
My two concerns with investing money into keeping your original FX3 dampers are as follows. First, they are old, and dampers do wear out. It might be possible to get them revalved if they are Bilsteins, but it will be expensive. Even if they are in good working order at the moment, they may not stay that way for long. Second, it doesn't look like the DRM kit does anything to relocate the shock mounts in the rear, which may be a problem. In the stock shock mount locations, a coilover spring gets very close to the halfshafts in the rear, and the kits I'm recommending relocate the mounting points to account for that. I don't know how easy it would be to import either kit from the US, though. I do recommend what others have said: do some searching to read up on others' experiences with the DRM FX3 kit. Despite my concerns, this may be the perfect thing for your needs.
Graulus, if that avatar image is your car, it's lowered intentionally - the springs haven't fatigued. O agree with dizwiz (it had to happen sometime!) that fiberglass leaf springs don't wear out unless they are delaminating. You can see that damage if you look at the springs, though. You can probably raise the rear ride height by threading the nuts holding the spring end bushings upward on their bolts. The front was most like lowered with lowering wedges in the center clamps and/or cutting down the pads on the ends of the spring. That's a more difficult job to reverse, but it could be done. This would allow you to keep the FX3 option if you want.
The springs Van Steel is selling are being made in the molds that they bought from Vette Brake Products when VBP went out of business. Back in the day, VBP springs were great. I have no reason to believe these aren't good quality. However, based on info gleaned from another forum member's recent experience combined with knowledge of how spring and wheel rates actually work, it seems that Van Steel doesn't quite understand how these things work. As a result, they are advertising springs stiffer than the OE Challenge Z51 sets as their soft-riding FE1 sets. If you do decide to go this route, let's discuss what they are selling so you can choose an appropriate set. This option lets you keep FX3 as well.
It's worth considering if FX3 is worth keeping, too. Its advantage is adjustable damping rates on the fly, obviously. There is value in that, but the question to consider is: how often do you actually change the settings while driving. Does your use allow for the possibility of stopping the car and taking five minutes to adjust individual damper ***** instead? I ask that because there are some high-quality coilover kits available in the US that have easy-access adjustment ***** on the shock bodies, and I think these kits will provide an overall better experience than the old DRM adapter kit you're looking at. The ones I have in mind are the Viking-based kits by After Dark Speed and the Fox-based kits from Ridetech. Going with these kits would provide you brand new dampers with proper adjustments and much better/newer damping curves than 33-year-old Bilsteins or Delcos (whatever the FX3 option was based on).
My two concerns with investing money into keeping your original FX3 dampers are as follows. First, they are old, and dampers do wear out. It might be possible to get them revalved if they are Bilsteins, but it will be expensive. Even if they are in good working order at the moment, they may not stay that way for long. Second, it doesn't look like the DRM kit does anything to relocate the shock mounts in the rear, which may be a problem. In the stock shock mount locations, a coilover spring gets very close to the halfshafts in the rear, and the kits I'm recommending relocate the mounting points to account for that. I don't know how easy it would be to import either kit from the US, though. I do recommend what others have said: do some searching to read up on others' experiences with the DRM FX3 kit. Despite my concerns, this may be the perfect thing for your needs.
Thanks for your reply. So if i understand correctly, i could also raise it back up by undoing the lowering? If that's the case then i would rather just do that. I'm not looking for track performance or anything, i just want to keep the fx3 system (i want to keep it as original as possible).
The car in my profile picture is indeed my car. Some more images:
Oh wow! You weren't kidding about wider body work! And those are some seriously dished wheels! So I'm going to retract my prior statement and say this instead: I think the car may actually be at stock ride height, but that front air dam and the side skirts are aftermarket and way lower than the stock pieces. If so, then your springs might both be good condition but the car just hits the ground because of those lower body pieces...and there may not be any lowering to undo. It's hard to tell with this aftermarket body work. If someone reading this has a know-stock 1992 with the FX3 suspension (73.2 N/mm front spring and 39.9 rear), then perhaps you could both measure from ground to the center of the front lower control arm bolt or some other clear reference point to compare ride heights? Also, we'd need to know what size tires you're running to account for any differences in diameter.
Oh wow! You weren't kidding about wider body work! And those are some seriously dished wheels! So I'm going to retract my prior statement and say this instead: I think the car may actually be at stock ride height, but that front air dam and the side skirts are aftermarket and way lower than the stock pieces. If so, then your springs might both be good condition but the car just hits the ground because of those lower body pieces...and there may not be any lowering to undo. It's hard to tell with this aftermarket body work. If someone reading this has a know-stock 1992 with the FX3 suspension (73.2 N/mm front spring and 39.9 rear), then perhaps you could both measure from ground to the center of the front lower control arm bolt or some other clear reference point to compare ride heights? Also, we'd need to know what size tires you're running to account for any differences in diameter.
It definitely sits lower than stock as i am hitting the headers on some occasions, the part where the headers and the exhaust are connected. I also easily hit the "front splitter" or whatever it's called. The body kit might make it lower than stock but i don't think it would make it that low, pretty sure it's a bit lower than stock.
as for tire sizes:
Front: 275/40 ZR17 98Y
Rear: 335/35 ZR17 106Y
Okay, your front tire size is identical to stock, which makes comparisons easier. Rears are actually slightly taller than stock, but not by much. The splitter part is technically called an "air dam," and it looks quite a bit lower than stock. Note that even stock C4s with the deeper air dam sometimes scrapped on steeply inclined entrances, but those were flexible so it wasn't as bad of a problem when they did. Do you know what headers you have? Some brands hang down much lower than others, and that might be part of your problem. OTOH, my 96 had a roughly 2" drop with Hooker 2051 headers and they didn't hang down at all, so they never scraped on anything. I'm saying all that to point out that the parts of your car that are scraping are all afternarket and therefore aren't a good indicator of ride height or spring health.
Okay, your front tire size is identical to stock, which makes comparisons easier. Rears are actually slightly taller than stock, but not by much. The splitter part is technically called an "air dam," and it looks quite a bit lower than stock. Note that even stock C4s with the deeper air dam sometimes scrapped on steeply inclined entrances, but those were flexible so it wasn't as bad of a problem when they did. Do you know what headers you have? Some brands hang down much lower than others, and that might be part of your problem. OTOH, my 96 had a roughly 2" drop with Hooker 2051 headers and they didn't hang down at all, so they never scraped on anything. I'm saying all that to point out that the parts of your car that are scraping are all afternarket and therefore aren't a good indicator of ride height or spring health.
Makes sense. I'm not sure what headers they are, they we're installed by the PO. So i'm not sure what to do now. I'd like it raised by an inch or so anyway.
If the original console door is in the car still and SPID label VIN matches the car post a snapshot of it to confirm original build. If not just post the VIN and I believe options could be confirmed. Do you have the FSM(Factory/Field Service Manual)? If you do, you want to do measurements and compare to information on 3-21 & 3-22 of the FSM.
Interesting build for sure. Was the car fabricated locally or imported as it is from the USA?
I don't have a FSM, i'll check the console door later.
This is a Corvette C4 made by Geiger Cars, a german car tuner, back in the day they bought C4's stock from the factory and made a Geiger Corvette from it and sold it like that. That included a wide body kit, those custom wheels, and a tune (The PROM has a Geiger sticker on it).
I have emailed the company before requesting information on the car but they said it's too long ago.
Makes sense. I'm not sure what headers they are, they we're installed by the PO. So i'm not sure what to do now. I'd like it raised by an inch or so anyway.
One very inexpensive way to accomplish that might be to cut some conveyor-belt material to shape and add that to the existing spring pads where they rest on the lower control arms up front. It's probably about a 2:1 change in ride height, so 1/4" of extra pad material probably would raise the ride height by 1/2". In back, you could add more fully threaded bolts for the spring ends and then thread the nuts that capture the bushings higher on those bolts. Start with just replacing your old rubber bushings (which are probably squished flatter than they were when new) with new urethane bushings from Energy Suspension. That alone might gain you some rear ride height.
Thanks for your reply. So if i understand correctly, i could also raise it back up by undoing the lowering? If that's the case then i would rather just do that. I'm not looking for track performance or anything, i just want to keep the fx3 system (i want to keep it as original as possible).
The car in my profile picture is indeed my car. Some more images:
C4 leaf spring to coilover while retaining fx3
