So I bought a 2003 Z06 and didnt like the stock stance one bit. It was looking 4x4 as hell. I searched many sites in search of a nice do it yourself on lowering my corvette with the stock bolts. I got many different ways on doing it and I wanted to share my way.

Lowering the front:

1. Jack up the front of your vehicle and place jack stands.
2. Not needed but it helped me out. Remove wheels. This gives a lot more working room.
3. Locate the leaf spring(its a 2x4 looking bar that runs from one side of the car to the other.)
4. You will find a bolt near the ends of that leaf spring, its a good Idea to now use so WD-40 on it to make things easier for you.
5. Use a small jack and place it under the A frame and jack it up so that the shock compresses, relieving pressure off the leaf spring.
6. With a 10mm socket mover that bolt in a counter clockwise motion till you can not spin it anymore.
7. Put wheels back on and remove all jacks. Simple as that.

Lowering the rear:

1. Jack up the rear of the car.
2. Remove the wheels. Again not needed but makes the job a lot easier.
3. Locate the leaf spring bolts just like the ones in the front.
4. Apply WD-40 to the bolts.
5. Use 18mm socket for lower bolt and just use a pair of pliers for the tops of the bolt.
6. Turn the 18mm socket counter clockwise lowering the bolt down. Lower the bolt till your at the last thread than stop.
7. Put wheels back on and lower the vehicle.



Follow my steps guys. Trust me its a simple job to do. Only takes less than an hour I promise.

 

Step 5 is not exactly correct for lowering the front.

Put a small jack with a block of wood on it under the end of the spring and lift the spring to take the pressure off of the bolt.

Look at the pictures in this link.

http://www.z06vette.com/diy_lower.php

 

For some reason, I can't see the picture, but having gone through this procedure, I agree. By jacking the a-arm, you're putting ADDITIONAL pressure on the adjusting bolt. You need to lift the spring away from the a-arm, relieving the pressure from the adjusting bolt, to allow it to be turned.

 

Couple of things to consider, one is you have altered you suspension settings. Once done it is good to get it realigned. Another is ride height/rake. At you jacking points font and rear both sides make sure the front is at least 1/4 inch lower, unless you never plan to go more than 95 mph. Remember measuring the wheel well heights is not always accurate and can throw your alignment off even more.

 

Correct!

The place the factory uses for "ride height" reference is the center of the pivot bolts, of the lower a-arms.

 

What happens over 95 if you don't have the .25 inch rake?

 

I would be worried about the alignment right after

 

There is the potential for the car to generate "lift" in the front, due to air passing under the nose of the car.

 

I do agree the C5 looks better lowered, but mine is low enough as it sits now. Mine is stock, and I think it will stay the way is.

 

Mine is lowered all the way on stock bolts and the front could definitely come down more..

Also Threadjack, those lines in the center of your tire tread.. My KDW's do that too, what is it??

 

No idea.

 

Yup, simple, but Chichi, now that you've totally effed up the setup of your car you can now take it someplace and have it set up properly. There are lots of ways to lower these cars and you've managed to screw it up by not understanding what you were doing and how to do it right.

Here is a link on the how to do it properly and why there's a right way and a wrong way to do it. Just spinning screws messes up the corner balance, and lowering it too much (like you just finished doing) ruins the ride and the cornering over bumpy surfaces.

Read this link and the realize that you've messed up.

http://forums.corvetteforum.com/1576940245-post92.html

Now, to fix it you can go back and try to set the front screws up about two to three turns from bottomed out, and set the rears at about two or three turns on the drivers side and about 5 turns on the passenger side and that will be close to the right spot. Or pay some money and get the car properly corner weighted at a good race shop. Lower might look better but too low screws up the handling, results in bottoming and loss of alignment, and can make the car ride like a buckboard.

Finally, get an alignment done after the springs settle because lowering changes the toe and that can eat tires.

 

Solofast,

How does the popular mod of using C6 Z06 shocks factor into your lowering recommendations? Also, how does corner weighting work?

 

There is no difference in rear shock length between the C5Z shocks and the C6 Z06 shocks so you will absolutely run out of travel even with the newer shocks. There simply isn't much travel to start with in the back and when you lower it too much you end up with less than an inch of travel before you hit the bump stops. Cutting the bump stops would help a bit, but the stock bump stops are very progressive and if you cut them down, when you hit them (as you eventually will) they will hit harder because they have been shortened.

Corner weighting is for properly setting up a car for high performance. A good driver can absolutely feel the difference in a car that has been properly corner weighted and one that is thoroughly screwed up. A clueless driver won't know the difference.

A car that is properly cornerweighted turns the same in both directions. A car that is off a good bit can push going one way and will be loose going the other. If you aren't going over .8G you won't probably notice, but if you are canyon carving or running autocross or track days it makes the car much more pleasant and it comes alive more when coupled with a good high performance alignment. It depends on how you plan to use the car and how perceptive a driver you are, but yes it's makes a difference if the car has been dorked with and screwed up. The car that is messed up will feel sluggish turning one way and will feel like it's on edge going the other.

I've set up a bunch of these cars and when done, the folks are generally amazed how sweet the car drives, and it's a totally different experience than a car that is set up from the factory. Adding some negative camber, resetting the toe, adding caster, lowering an inch and corner weighting makes it a very very responsive car.

That said, if you are just doing street driving I would just recommend that you find a flat surface, measure from the frame rails and set the car up with about 5 inches of ground clearance at the front jacking puck hole and 5.5 inches in the rear jacking puck hole, and it will be good enough.

These cars come from the factory not that far off on corner weights. Because the frames all aren't quite straight, the factory setup procedure accounts for this and the cars come out pretty close. If you turn the screws the same amount from side to side you won't mess that up. Moreover, if you turn the front screws in full turn increments it won't change the relative position of the screws on the front control arms and it will settle out in just a quick trip around the block. If you turn the front screws different amounts than full turns the plastic has to distort and that is what takes time to settle out, and this also messes with the corner weights.

 

There are different upper rear shock plates out there. My C5 and my replacement C6Z06 shocks both had a plate with a lowered center where the shock bushing rides. I'd guess that you lose about 1/2" of shock travel with this plate. Now, someone here posted pictures of a plate they claimed came from a C5Z06 and it was flat. Using that plate I think I'd gain maybe 1/2" of shock travel.

I cut my bump stops in 1/2 and it helped with bottoming out. I can't have more travel in the rear because my rear tires will just touch the outer fender lip part way down the sidewall at full compression. If they cleared, I would be changing the rear upper shock plates to a flat plate.

Removing the front adjusters and using longer bolts in the rear is for show cars where the roads are really smooth without any bumps because the car will have no suspension travel left and handle like crap.

The main thing to remember when changing ride height is to turn the left and right adjusters on the front and back equal amounts. Don't just go all the way.

 

I do not have any problems with the car after lowering it. I have taken it up to 150mph and have not had any lift in the front. The car still has some foward rake to it which is what everyone wants. I need new tires because the ones on my car now have some dry rot issues. I recently was given a rear set of Falken Azenis 615 K tires from a D1 drift event that came through my city. Thank you team Falken. They were used for one run and still have good thread on them. Ill be using them for now until I can get new tires. Im looking at getting the Bridgestone Potenza RE760 sport tires. HAs anyone used them before. And I will be getting an allignment when I put the new tires on.

 

If you have 0 rake the front end starts to become lighter and harder to steer. If the front end becomes higher than 0 rake you start to become more of a wing than a sports car. Usually owners try to slam the car to the max at each corner so the front is lower. All you do then is wear the insides of the front tires out.