MaxZR-1

Hi everbody,Ive got a 92 ZR-1 that Id like to lower but Im not too sure how do go about it.I checked into a set of coilovers but was told Id have too modifiy the shock towers and that wont work.What would I need to do to lower the car and how much lower will it go.Thanks for any input on this.Max.

Cdn Z06 Mike

this was previously posted.

http://www.digitalcorvettes.com/foru...ad.php?t=79763

Greybeard ZR1

You don't say if you're lowering the front, rear, or both, and what for? Looks? Better handling? weight transfer at the strip?

To me, the stock height of the ZR-1 looks fine in the front, but the back seems to sit high. So I got the lengthened C4 rear spring bolts (available in most Corvette accessory catalogs. Cheap, easy. It drops the rear to wherever you want it. 1 1/2" was perfect for me.
Since then i've heard some opinion that lowering the rear does not help weight transfer at launch in the 1/4mi. In fact it might hurt 60ft. times. I don't know for sure about this. But for me, the car sits just right.

BAM92

Nice write up.

FastZR1

I lowered my old 91 by cutting off the rubber bumpers on the top of the spring in the front. Then we glued the aftermarket phonelic blocks in place so the spring wouldn't contact the frame. Had to trim up the metal brackets that hold the spring in and put everything back together. Lowered the rear with some longer bolts and then got the car alligned. I couldn't have done it without Shrek's help!

I may have an old picture of the completed job. I'll post it later if I can find it.

DMark

I now have Ed's car. Check "My Corvette Photos" for how it looks.

FastZR1

Here is the old girl.

Rkreigh

the stock shock towers work just fine with coil overs. you need to move the sway bar and drill a few holes, but I'd sure consider coil overs, just don't go too crazy on the spring rates. I really like this mod and and very pleased in how it helped the car stick to the road better and it allows the full range of adjustment, varying spring rates, ride, height, ect.... disadvantage is cost. but since you have to remove the front spring, it's half the battle.

the need to modify the shock towers is a bit urban legend IMHO. I talked to dave M. about this and he saw no need. they look flimsy, but actually are pretty strong unless you are beating the car up on the track and bouncing over curbs.

96GS#007

For the front, there is a pad on each end of the front spring. I cut about half the pad off and it lowered the front ~3/4". To lower it more you need to cut the rubber mounting pads off as mentioned above. Cutting the tip pads takes about 30 minutes/side assuming the lower ball joint and tie rod pop loose easily from the spindle.

Here are the pads I cut off...

glass slipper

Spring rates are not adjustable on coilovers...unless you're talking about changing the whole spring. But then you could say the stock setup is adjustable. Coilovers are mainly for the track where you need the increased roll stiffness provided by higher rate springs. It'll be a very rough ride on the street unless you go way soft on the spring rate...but then you might as well keep the stock spring as it will outperform a coil spring of the same spring rate. Due to the mounting of the stock front spring, it provides additional roll stiffness in a corner by bending into an "S" shape in the middle third and transmitting some of the "load" to the other side. A very high tech design that the C5 and C6 incorporated into the rear spring.

Blown67427

Make sure that the area you'll be driving in, won't be coming in contact with the underside of your car all the time. Lowering the front any can cause issues with drivability. There are speed bumps in parking lots that my car won't go over without scraping. Then there's those lovely imperfections on the road.

94ZR1

I thought about doing this but it is hard enough to get my fat azz in there already

DMark

Old Girl - OLD GIRL!!!!

Ed, She is in the Prime of Life!

Uhhhhh...., Just as soon as I get these out-of-round BFGs off of her.

Now if you really wanted to show her in her prime you would find that smoking 360 video and post it.

marc.madmax

The wheels are different than original, with lower aspect ratio tires. 18" with a 35 series. That seems to be why that car look like a 4X4. Stock the setup looks and runs fine to me. To me, the wheels change the handling of the car, especially if you change sizes, width, offset, not to mention the type of wheel with its deflection. Then the differences of the tire, the spring rate of the smaller sidewall, tread, etc etc...

I think that when you change the wheels from stock that you would adjust height, spring rates, shock valving, even the sway bar to get the config right again.

Even now I am torn as to changing wheels to 18's for a big brake setup as I would have to add even more to get the handling back to the way I like it. (If I keep her, I am on the fence as to selling)

LT4POWR

FastZR1

Old to me. Sometimes I wish she was still in the garage.

ZR-71

That's the look I like.

I did the same to mine.

http://i48.photobucket.com/albums/f2...sVet2013-1.jpg

DMark

Ed...., with all of your Combat & Sea Duty pay I'm sure we could work something out.

FastZR1

Can't. Stock market is killing me.

steve40th

When you did the Z, did you take the aluminum shim out that would have gone above the urethane wedge? Or did you put it back in?