I have an O1 Z06 that I take to track events 4-5 times a year. After doing much research, I have finally committed myself to lowering the car to improve the handling. Per the video that came with the car from GM, they state that the C5 can be lowered 12-14mm (about an inch) to improve handling without the suspension bottoming out. But they also spoke of camber adjustments that could be made with the upper and/or lower A arms.
My questions are...when you lower the car, would that not automatically add some more negative camber? Does anyone know how much additional camber (1 inch lower) actually adds? Besides the car completely scraping on driveways are there any other concerns or negative benifits to lowering the car only 1 inch? I have also heard that you might want to get the car realigned after 1 week of driving...are the allignment specs the same as stock?

I know I have a lot of questions, but I want to make sure I do this right the first time. Thanks for any help!

 

Some of the track folk will chime in here, no doubt -- but they might want to know more about what kind of tracking you do. As for the other questions, I can only be vague, and can't answer everything. But I'd submit the following to you:

- The GM video's recommendation is a "rule of thumb" that can be followed to a T, or completely ignored. I took m,y car down past their suggestions, and love it. Then again, I don't track my car.

- People who have gone lower than the video (or as low) swear by Bilstein shocks as completing the lowering/handling package.

- The "best" way to lower the car for racing is probably with coil-overs, though that can get very expensive.

- I don't know just how much camber is added, but yes, you ought to get an alignment done after lowering, 'cause things WILL be out of whack. I'd suggeset waiting longer than a week, since the car will need to settle (with time) into its new ride height, and that MAY take longer than a week.

- I had my car aligned with the stock settings, but I also dropped the car further than you plan to, and I don't track it. You should ask about what settings people are using for the type of racing you'll be doing.

- I don't see any negatives to lowering the car an inch, save for just needing to be more careful about clearances in everything you do (including getting a jack under your car). That being said, I follow the "the lower, the better!" train of thought. Maybe one problem with lowering the car an inch will be that you find that you want it even lower. But that, at least, is always doable. ;)

Good luck!

-Kirk

 

Acutally the 12 to 14 mm the video talks about is between 1/2 to 3/4 of an inch, not 1 inch. You will get some additional negative camber but with out the camber curve we can't tell. The alignment you want depends on what you want to do with the car. For everyday driving the stock setting is the best. If you want more on this let me know. :seeya

 

I lowered mine full on the front with the bushings left on, and aftermarket bolts on the back, the back is very low. This changed my camber to -1.5 all around and I loved the way it handled. It was not "out of whack" all the settings were stock except camber, which increased from the +0.5 to -0.7 the stock values. Now I ran the heck out of this car (5 auto-x and 384 miles of the Nurburgring) and wasted the tires and pads at 10K miles, the inside of the front tires were down to the cord because of the camber. For the winter I put on the TOYOs and set the alignment back to stock. But when it warms up I'm going back to at least -1.0. You do not need new shocks, the Z06 shocks were made for the track and they work great from auto-x to 171mph on the autobahn. There are many, many issues and variables with coil overs you need to research before you buy. Many of the serious track guys have the GM T1 bars and Bilstein shocks and love it. I’m not there yet as I am a beginner and I’m very happy with the stock suspension. I have now the A&A wheels and bars for when I scrape, I’m glad I got them and wish I could have installed the bars before going to Amsterdam for New Years.http://forums.corvetteforum.com/zerothread?id=464363


[Modified by CPT Z06, 10:41 AM 1/4/2003]