BlueDragon

We all agree on one thing, your set up is not dead on! the best advise I have is to use the settings referenced above (stock) and go find a shop that has extensive experience setting up Corvette suspensions. I have found for most shops the corvette suspension/alignment is over their heads.

Make sure they have a good alignment machine and are set up to do 4 wheel alignemnts.

With the corvette, you essentially have two front ends!

I have a fairly sophisticated set up with coil overs, bump steer kit, and heavy sway barsand lowered. I have found only one shop in the area that fully understands the system and they are a full race shop.

Take the info you learned here and discuss it with the alignment people, let them know you understand the system. Helps keep the BS out of the equation!

lionelhutz

Ya, if your car spends most of it's time in corners then lots of camber is great. But, if the car will be run on the highway then the wheels need to be fairly level to keep the wear in check. It's nice to recommend "spirited" settings but you should give the negative aspects of the settings as well. If the OP is running wider aftermarket wheels then the inside edge wear would be even worse than what he'd see with stock rubber.

I have wider rubber and bigger sways and new shocks on my '98 and do some spirited driving but the places to do the driving are far between around here and I do drive in a straight line too. I have -0.3 degrees - at $400 a pop for the RE-11's I really don't feel the need to destroy the inside edges of them and throw out an otherwise good set of tires. I had -1 degree with the PS's that were on the car and when I changed them there were cords showing on the inside edge and about double the wear bar thickness of tread everywhere else. That set probably could have gone another 10k+ miles if I'd paid attention to the wear and got the alignment changed much earlier.

Peter

AU N EGL

Event -1* camber up front wont hurt but help handling. We have that on my wifes vett

-0.3* is not easy to set up even with the best of machines or technicians. -0.5* is about as accurate as any one can get.

Set up a car at -0.3* take it off the machine, bounce the fenders up and down a bit, drive around the block with a few left and right hand turns, put the car back on the machine and see.

One you get your alignment done, dont forget to mark the concentric with a magic marker. You will be surprised home much things slip and change.

An air pressure change of 4-5 psi during driving will change the camber that much. One small pot hole and the camber changes,

and 10K miles on performance tires, is about the max. Tire gets too old and too hard for any stick or grip. Tread depth is rain water run off, not grip.

Normal passenger car and light truck tires are 7 years, 50,000 miles. Performance tires are 2 years, 10,000 miles. After that, the safety factor is just about gone. Rubber is too hard.

But it is your car.

lionelhutz

Well, it's true that the PS's were getting old and I didn't mind getting rid of them anyways. Still, I'll run more than 10k in a summer so I need the most life I can get out of the rubber I put on it.

I'm still not sure how air pressure would affect camber though - assuming that all the tires gain the same pressure, which they typically do. I can change how the tire contacts the road but I don't see how it can change the actual camber setting.

Peter

Bimmervet

This is right on.
I had a similar experience with my BP race Car years ago. We did everything to stop the pull and nothing worked untill a Rep. from B.F.G. pulled off both front tires and measured the circumference and one was off by about 1/2". Replaced both tires and everything was fine. I know this was a fluke, but it happened.

AU N EGL

peter

The tires dont gain the same amount of pressure.

Tires just sitting in the sun will gain 5-10 psi. Then driving an other 5-7 psi. This will cause the tire to deform or budge in the center of the tread. That changes the camber and how the tire rides on pavement.

Park your car in the sun. facing north or south.

measure all four tires at 8 am. Then 11 am an notice how the tires on the east side of the car are 4-6 psi more then the west side of the car.

called Sun tires.

lionelhutz

I guess I don't live where the sun is hot enough to cause this. I've never seen more than 1psi variation side to side watching the TPS. The car does tend to gain 4 to 5 psi driving.

Peter

AU N EGL

Dang Peter, we need to get you to move SOUTH into the SUN.

so have to wear shades most of the time

ArKay99

This is something I've just started getting into. Lot's to learn here. There's a lot more to getting your car to perform than just adding power and brakes. With all the money and work put into mods, you'd be better off flushing the coin down the toilet and sitting on the couch if the car isn't set up to handle well.

BlueDragon

Ya, you can pour a bundle into these cars for performance, but if not done RIGHT it is a total waste of money! Suspension mods are very typical of that.

I have a completely modded out suspension with Phadt coil overs Hotchkis sway bars, Neoprene bushings, big tunnel plate, bump steer kit on all four corners, lowered (not all the way), Rims, Tires etc. At the end of the day if the alignment is off even a small amount it is all a waste of money. For example talk bump steer with most alignment mechanics and they will look at you like you live on the moon! In reality bump steer alignment is a time consuming process and to get it right really takes someone who knows what they are doing.

Bottom line:
I get great wear on the tires Mich PS2s. 315s on the rear 295s on the front.

This car pulls some serious Gs in a turn and with Hoosiers, you almost need a G suit

AU N EGL

Mod order

Contact patches first

tires,
Great alignment
Brake pads, brake fluid and brake cooling
Seats and harnesses
maybe tuning the stock engine too

Then nothing but seat time and more seat time.

Next suspension mods


Not as sexy as saying "hey I got 550 rwhp LS1"

But then again, driving skill will almost always beat modifications when the results are posted.

BlueDragon

Ah Men! At autocross or open track, I can beat a lot of cars that have much more HP than me. Sometimes it is the Hp that gets them in trouble!

It took me a few months to get the suspension dialed in for good performance and good tire wear (contact patch) but now she will cut a sharp turn at 80 and not even squeek a tire, or lift a fender.

Streetk14

Just wanted to clear a few things up for anyone that does not know. Alignments are something that most people do not understand, and are nothing more than a bunch of numbers on a sheet of paper. I am a Technician who was factory trained by Hunter Engineering on the use of their alignment equipment, FWIW.


Caster: Excessive cross-caster (difference between left and right) will always cause a pull to the LEAST POSITIVE side. In the OP's case, this would cause a tendency to pull or drift to the left

Camber: Excessive front cross-camber will always cause a tendency to pull or drift to the side with the MOST POSITIVE camber. In the OP's case, this is also going to make the car want to drift to the left.

Thrust angle: When this is off, it is also referred to as "dog tracking". Basically, the front and rear axles should be parallel to each other. If the rear toe is off, or uneven, this will cause a thrust angle problem.

In the OP's case, look at the difference between the left and right (.04 and -.02). This means both rear tires are pointing to the right slightly. Toe will ALWAYS want to equalize when driving down the road. This means that the car is going to be pointing to the left driving down the road (slightly, of course). What the driver will notice mostly is that the steering wheel is usually not straight. This happens because the car is dog-tracking and the front toe will also want to equalize. This makes the steering wheel off-center when driving straight, but will not cause a pull.

To sum it up, the OP needs to find a better alignment shop. Just because everything is in the "green" zone on an alignment screen does not mean the car will drive properly. Find a good performance alignment shop or someone who knows Corvettes.

Andy