I recently purchased a 01 z06 and am taking it to the track in may for the first time, the car is currently lowered using bolts on leafs and when you look at rear control arms they are angled the wrong way.
What is better having the lower center of gravity or having the control arms even as they are on a stock height c5?

Also what would a good track alignment be?

thanks

 

I use -2.5 camber in front and -1.5 in back with Hotchkiss bars and Doug Rippie Bilsteins. Pretty happy with the overall result.

 

The car should be lowered about 3/4 of an inch from the stock ride height. If you take your car to a premier setup shop (like Phoenix Performance) that's what they do. With your present setup you are already on the bump stops in the back and that's a no non for proper handling.

Get rid of the lowering bolts and get it properly set up and corner weighted, put in as much negative camber as you can get in the front (usually about 2 degrees for most stock cars if you are making it equal on each side), a degree and a half in the back and as much caster as you can get with that negative camber and you are done.

The rear toe should be about 1/8 of an inch of toe in.

Front end toe is like Thai food, hot is a matter of taste. If you drive the car on the street you want about 1/8 of an inch of toe in for daily driving so that you don't eat your street tires. Mark your front tie rods with a stripe of paint or nail polish. When you get to the track and change to your track tires turn each tie rod an equal amount towards toe out. One full turn will go from 1/8 toe in to 1/8 of toe out. That's a good starting place but you may want to use as much as one and a half turns depending on the track you run at.

Also, when the tech is doing the alignment, he needs to gorilla torque the suspension eccentrics. After they are torqued, mark each one with a paint stripe. Often they slip and if they are marked you can return it to the proper alignment without having to take it back to the alignment shop.

Finally you should start hanging out on the Autocross and Roadracing page of the forum in the general section. All of this info is in the sticky there and a lot more on setting up your braking system and other things you need to know about tracking the car.

 

If you are a beginner have the car aligned and go to the track. You have a steep learning curve.

 

I agree with these comments but I don't believe the OP is at this point yet.

I COMPLETELY agree with this. These C5Zs are set up well from the factory for most of us. I matched my fastest lap times in my 2001 the first time at the track as I did in six years in my 1997 Mustang Cobra which had all kind of suspension as well as intake and full off road exhaust. These cars in stock form are more than enough to learn to handle. Get you some fairly sticky tires and go work on the driver mod. That's where I am at with my car. Six years behind the wheel of a Mustang is a completely different feel than a Corvette, even a Cobra to a Z06.

 

I concur...............at least at first, return your car to (aggressive) stock alignment and stock height minus 0.5" (per your owner's manual) or (up to) minus 0.75". Then seat time, seat time

 

Some great info on setup. Best info is seat time, seat time for a first timer or someone with limit track time. Learn the car before changing components.

 

Thanks for info I can feel the car bottom out on big bumps in the rear, it was done this way when I bought it, I will raise it for sure, what kind of tires do you guys suggest for track that will also work if it rains on track day?

 

While the OP is a newbie the reality is that if you don't do a proper alignment you'll go thru a tires at a track day or two because it will end up eating the outside of the tires. Doing an alignment is necessary also because he has to raise the car back up to a proper ride height, and that is also a necessity since he's bottoming right now and the car will handle really funny if he doesn't. Marking the excentrics and tie rods actually saves money because if they slip he can put it back to right in a few minutes, where if he doesn't he will have to go put it on an alignment rack and pay to have it put back where it needs to be.

Bottom line is that an alignment needs to be done anyway, and he should go find a local shop that can corner weight the car so that it will handle as it was intended to. Since it's been lowered improperly the corner weights are going to be as much as 100 pounds off, and this will make the car handle oddly since the Rf and Lr will be heavy. Doing that first is really just maintenance and that needs to be done before he starts to track the car. If the car was as it left the factory I'd say leave it alone, but since it's already been messed with it really should be put back to a proper setup. I can't imagine taking it to the track the way it is now, so while it will cost a minimal amount to have it done, it really needs to be done before he puts the car on the track.

Also he really needs to get a set of good pads and flush the brake fluid and clutch fluid before he goes to the track. Again these are just maintenance items, but if he doesn't do them it could end up with boiling fluid and ruining his day.

Taking a car for a track day isn't like a parking lot autocross you do a lot of cornering and generate a lot of heat in the brakes. It's a good idea to make sure your car is up to date maintenance wise so that you don't have problems that could make your day a lot shorter and not as much fun.

Since the OP is taking a 14 year old car to the track there's going to be some maintenance required before he takes it to a track day or he's going to have problems and be disappointed.

 

Does the owner's manual really suggest lowering the stock height by .5"?

 

My owner's manual says: for track usage, "recommend lower ride height no more than 10mm...". NOTE: 10mm is approx 0.5"

 

I was looking at a used set of 18" Fikse wheels so I can rotate track tires but I'm wondering what you guys are doing about the active handling throwing codes by having the wrong size up front?

 

Good info, the car has 36,000 miles and has a rebuilt shortblock with good rods and pistons along with a stock 01 LS6 cam that is reground to the specs of a GM hotcamish! Full exhaust from front to back and a tune. It has a fresh t56 with all the upgrades and a new Mantic 9000 twin disk clutch with all new hydraulics, I have only 230 miles of breakin on all these parts so far.
So it looks like I need to maybe get braided breaklines and flush entire brake system with motul 600, get car scaled and raised along with an alignment and start from there.

How are you guys scaling car? are you using stock bolt height to transfer resting weight?

 

Covered in the autocross and roadracing section, but bottom line is that it doesn't kick in if you turn off the nannies...

Lot's of folks run a "square" setup on the track but you are going to have to adjust sway bars if you go that way. Not recommended for a newbie since you're going to have learn how to tune the car and then drive it. What often happens in that case is that since you really don't know what you are doing you screw up the setup and then you end up "driving around" a bad setup and you can learn bad habits as well as not progress as quickly. Better to keep the car stock until you get up to speed so to speak.

If you go that way you should copy the setup item for item from somebody who has done it already and has figured it all out. Otherwise you will be trying to learn and making setup changes at the same time and that's not a good place to be.

Corner weighting is done on a set of 4 scales and any good race shop should be able to corner weight the car and get it set up properly very quickly.

Depending on the part of the country you are in someone here can point you to a good shop.

 

It is the OVERALL diameter of the tire which the computer reads, NOT the wheel size. Just check the manufacturer's tables for "specifications" to see what the tire diameter is. For instance, you might use a "35" aspect ratio up front and a "30" aspect ratio in the rear..................

 

really the sway bars effectiveness is effected by the rim size?

so you guys are actually bolting weight bars or something with weight to chassis of car? If so what methods are you guys using for the C5, placement and type of weight product?

 

You don't bolt any weight onto the car to get it corner balanced. You use the jacking screws on the springs to get the cross weight to zero (sum of the LF and RR is equal to the sum of the RF and LR).

Most folks going to a "square" setup are using the same size tires on the front and the back. The original setup on the Z has larger tires on the back and if you put bigger tires on the front that will change the balance. To compensate for that you'll need a bigger front bar to get the balance back.