Want to lift my C4 suspension to a functional height
#21
Instructor
Purchased my 94' C4 nice and low from an older gentleman. Looks great! But rides like crap. I'm bouncing all over the place like a kid in a lowered Honda. I was going to check to see if I was riding on bump stops. But I think I just want to lift it back up close to stock height. Some people in here have told me I may not be able to lift the front back up depending what was done. The guy had a Corvette shop do the drop. Here's at it sits now.
I lowered our '84 last summer and it sits about like yours does. I removed the wedges on top of the spring and I thinned out the pads on the ends of the spring too. Total drop was about an inch and I don't find any difference in ride quality. The '84 was known for a particularly harsh ride to begin with so my comparison might not be fair to your car.
I mention this because I'm not sure you'll find ride improvement for your efforts. If you don't have experience with other C4s (like me) maybe find someone in your area who can take you for a ride in their stock configured car for comparison before you go to the effort and expense?
It's all about personal preference, but for me even if the ride were a little more harsh the aesthetic improvement would be worth it - but that's just me.
#22
Burning Brakes
Thread Starter
I lowered our '84 last summer and it sits about like yours does. I removed the wedges on top of the spring and I thinned out the pads on the ends of the spring too. Total drop was about an inch and I don't find any difference in ride quality. The '84 was known for a particularly harsh ride to begin with so my comparison might not be fair to your car.
I mention this because I'm not sure you'll find ride improvement for your efforts. If you don't have experience with other C4s (like me) maybe find someone in your area who can take you for a ride in their stock configured car for comparison before you go to the effort and expense?
It's all about personal preference, but for me even if the ride were a little more harsh the aesthetic improvement would be worth it - but that's just me.
I mention this because I'm not sure you'll find ride improvement for your efforts. If you don't have experience with other C4s (like me) maybe find someone in your area who can take you for a ride in their stock configured car for comparison before you go to the effort and expense?
It's all about personal preference, but for me even if the ride were a little more harsh the aesthetic improvement would be worth it - but that's just me.
#23
Safety Car
The way the front spring works in these cars is a lot easier to explain with hand movements and gestures... part of what the lower kit does is allow the spring to be mounted farther up in the frame cross-thru which allows it to unspring a little (arch more). This results in less pressure on the end pads that contact the front control arms. Less tension holds up less weight so the car drops until the spring compresses enough to hold it up. It is like lightening up your spring which is a very un-hi-performance method to lower the car. Proper lowering springs are thicker and flatter to maintain suitable stiffness.
Now the spring isn't so much less tensioned that it doesn't work, but the fact is that the slammed C4's have no suspension travel because they are darn near riding on the bumpstops. You may not even get enough stroke on the fronts for the shock valving to really even work right. Coil overs are the way to lower these cars or the VB&P aftermarket front spring is also a good way to go. My preference is stock ridge height with one of the stiffer springs from the factory with good shocks. Not dragging the air dam 17 times on the way to work is much less aggravating.
Now the spring isn't so much less tensioned that it doesn't work, but the fact is that the slammed C4's have no suspension travel because they are darn near riding on the bumpstops. You may not even get enough stroke on the fronts for the shock valving to really even work right. Coil overs are the way to lower these cars or the VB&P aftermarket front spring is also a good way to go. My preference is stock ridge height with one of the stiffer springs from the factory with good shocks. Not dragging the air dam 17 times on the way to work is much less aggravating.
#24
Burning Brakes
Thread Starter
The way the front spring works in these cars is a lot easier to explain with hand movements and gestures... part of what the lower kit does is allow the spring to be mounted farther up in the frame cross-thru which allows it to unspring a little (arch more). This results in less pressure on the end pads that contact the front control arms. Less tension holds up less weight so the car drops until the spring compresses enough to hold it up. It is like lightening up your spring which is a very un-hi-performance method to lower the car. Proper lowering springs are thicker and flatter to maintain suitable stiffness.
Now the spring isn't so much less tensioned that it doesn't work, but the fact is that the slammed C4's have no suspension travel because they are darn near riding on the bumpstops. You may not even get enough stroke on the fronts for the shock valving to really even work right. Coil overs are the way to lower these cars or the VB&P aftermarket front spring is also a good way to go. My preference is stock ridge height with one of the stiffer springs from the factory with good shocks. Not dragging the air dam 17 times on the way to work is much less aggravating.
Now the spring isn't so much less tensioned that it doesn't work, but the fact is that the slammed C4's have no suspension travel because they are darn near riding on the bumpstops. You may not even get enough stroke on the fronts for the shock valving to really even work right. Coil overs are the way to lower these cars or the VB&P aftermarket front spring is also a good way to go. My preference is stock ridge height with one of the stiffer springs from the factory with good shocks. Not dragging the air dam 17 times on the way to work is much less aggravating.
#25
Safety Car
I think it depends on a couple of variables, but the sway bar does get moved. some people have figured out slick ways to mount the rears...at one time I was considering a front only coil-over conversion until I found an unmolested ZR-1 spring. I have an idea to make delrin spacers that mate up to those aftermarket lowering wedges to be installed with the factory spacer to raise the car to almost factory height. This way can be done by just separating the ball joints, but you don't have to take out the spring.
#26
Burning Brakes
Thread Starter
This idea I would be highly interested in.
#27
Would you just use a shim for a template? Then just use the stock height retainer?
#28
Safety Car
Member Since: Aug 2006
Location: Port St. Lucie West Florida
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I would personally take a ride to the shop asking exactly what was done. Once you get all the facts then you can start to address the modifications or possibly have them restore it to the correct height. Btw beautiful car and color. Good luck
#29
60 or less minutes on anyone's lift should enable enough information to determine the next best move.
#30
Safety Car
The other wildcard is that, if done right, the spring clamp brackets should have had a 1/4" milled off of their height. I know some people don't handle that part of the mod which would making it much easier to go back to something like a stock bushing height.
#31
Burning Brakes
Thread Starter
I'll be dropping my car off to have the front end raised up. I spoke to the guys at Top Flight Corvette here in town. I remembered them as I use to deliver to them back in the day, when I was a delivery driver at the Chevrolet dealership. The owner is super nice and told me he can do it all for $200. I told him I don't know if it needs a new spring. He said not to worry, he has a few extra Z51 springs and will give it to me for $75 if I end up needing one.
He asked if I wanted it completely back to stock, I told him maybe an inch lower than stock? He said that's fine and it would be plenty.
He asked if I wanted it completely back to stock, I told him maybe an inch lower than stock? He said that's fine and it would be plenty.
#32
Drifting
I'll be dropping my car off to have the front end raised up. I spoke to the guys at Top Flight Corvette here in town. I remembered them as I use to deliver to them back in the day, when I was a delivery driver at the Chevrolet dealership. The owner is super nice and told me he can do it all for $200. I told him I don't know if it needs a new spring. He said not to worry, he has a few extra Z51 springs and will give it to me for $75 if I end up needing one.
He asked if I wanted it completely back to stock, I told him maybe an inch lower than stock? He said that's fine and it would be plenty.
He asked if I wanted it completely back to stock, I told him maybe an inch lower than stock? He said that's fine and it would be plenty.
#33
Burning Brakes
Thread Starter
I have been reading up on it amd it seems to be a pain in the ***. For the price of the tools I would need and time, $200 is not a bad deal at all. The owner also told me if it's not to my liking, he will set it however I want it for nothing.
#34
Measure through the center of the front spindle to hood edge now on a straight/level surface and consider jacking the front at front x-member to a height that you believe you want before you take it. I'd probably do a snapshot of it also sitting at the height you like.
Take your heights with you for the fellow in the shop to use as references.
#35
Team Owner
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The fronts are like you guessed, in the front shocks.
IMHO install a stock front spring and mounting saddles/bolts for your suspension RPO.
Then crank up the rear to match.
Find a set of Bilsteins and call it a day...
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Conner Lake (03-29-2021)
#36
Burning Brakes
Thread Starter
I just maxed out the aftermarket lowering bolts in the rear to maximum rake. It did make quite a difference in ride and looks better with the rake. Maybe once the front is done, it will even out. One thing I noticed is I had to turn one nut alot more than the other and one side still looks a little lower. Rubbers are also worn out where the bolts are on upper and lower.
#37
I just maxed out the aftermarket lowering bolts in the rear to maximum rake. It did make quite a difference in ride and looks better with the rake. Maybe once the front is done, it will even out. One thing I noticed is I had to turn one nut alot more than the other and one side still looks a little lower. Rubbers are also worn out where the bolts are on upper and lower.
#38
Instructor
Returning the car to stock ride height and quality is as simple as installing a new OE spec (non-Z51) spring in the front and OE length bolts in the rear.
The Z51 spring is the stiffest available (the only spring available in 1984 as I understand - and the harsh ride they provide is the reason GM offered this only as an option for later models with something softer as standard). I don't think you'll find that Z51 spring to ride any better than whatever is currently in place regardless of what it does for ride height. I hope you do, but I'm not so sure. If the mechanic understands what you're after I'd think the last thing he should be installing is a Z51 spring, but I'm certainly no expert and hopefully he is.
I agree with comments about how lowering ride height MIGHT not allow the shocks to do as much for ride quality as they can at factory ride height. This stands to reason, but I don't know that this is true and if it is I question whether the difference is one that most of us could detect. Maybe...
I still say that when all is said and done I don't know that you'll find improvement in ride quality and I say this because I didn't find any discernible loss in ride quality going in the other direction. I wish you good luck!
The Z51 spring is the stiffest available (the only spring available in 1984 as I understand - and the harsh ride they provide is the reason GM offered this only as an option for later models with something softer as standard). I don't think you'll find that Z51 spring to ride any better than whatever is currently in place regardless of what it does for ride height. I hope you do, but I'm not so sure. If the mechanic understands what you're after I'd think the last thing he should be installing is a Z51 spring, but I'm certainly no expert and hopefully he is.
I agree with comments about how lowering ride height MIGHT not allow the shocks to do as much for ride quality as they can at factory ride height. This stands to reason, but I don't know that this is true and if it is I question whether the difference is one that most of us could detect. Maybe...
I still say that when all is said and done I don't know that you'll find improvement in ride quality and I say this because I didn't find any discernible loss in ride quality going in the other direction. I wish you good luck!
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Conner Lake (03-29-2021)
#39
Burning Brakes
Thread Starter
All I got to say is that I rode in a stock 91 zr1 today (mike) and the ride was amazing compared to mine(thank you for the ride Mike!)
Terry, I think returning my car to stock has to make a HUGE difference! Right now when I hit dips on the freeway, my *** is coming off the seat and my head has hit the targa top. I know there is no way that will happen with stock height. I think I'm going to lift it to stock height, get some Bilsteins and swaybars and call it a day. I'll replace bushings as time goes on while I'm replacing other things.
Terry, I think returning my car to stock has to make a HUGE difference! Right now when I hit dips on the freeway, my *** is coming off the seat and my head has hit the targa top. I know there is no way that will happen with stock height. I think I'm going to lift it to stock height, get some Bilsteins and swaybars and call it a day. I'll replace bushings as time goes on while I'm replacing other things.
#40
Le Mans Master
Just to throw this in the mix for thought.
My '96 was never lowered, however, I did let the shocks go a little too long, to about 140k. I would drive over any imperfection in the road and feel it. Bumps? Well, just say I had to reset my rearview mirror everytime.
I put a set of new Bilstein Z51 shocks on it and the difference was night and day. The old ones were so worn, the new ones actually raised the car a little. Point is, a worn out, sub-par shock on these cars can have a tremendous effect on many things.
I do agree that yours is sitting a little lower than I would want though.
My '96 was never lowered, however, I did let the shocks go a little too long, to about 140k. I would drive over any imperfection in the road and feel it. Bumps? Well, just say I had to reset my rearview mirror everytime.
I put a set of new Bilstein Z51 shocks on it and the difference was night and day. The old ones were so worn, the new ones actually raised the car a little. Point is, a worn out, sub-par shock on these cars can have a tremendous effect on many things.
I do agree that yours is sitting a little lower than I would want though.