jlvink66

I have done several searches on ride height and corner weighting and I have been very impressed with the amount of knowledge and experience on this board. I have not found much C6 Z06 specific info, so I have a few questions.

I am just transitioning from running a mostly stock setup (including tires) with exception of Carbotech race pads to the following mods;
- Hoosier R6's, 295x18 front and 325x19 rear
- Hardbar camber kit
- Stoptech St-60 big brake kit for the front wheels
- Hawk DTC-70 front pads and DTC-60 on the stock rear brakes
- LG spindle ducts

I'm thinking of running -2.5 deg front camber and -2.0 deg rear camber. I'll be swapping to a street alignment after each race so I don't wear my stock tires. I cut the rear ride height rubber bushings and with the adjustments maxed out I lowered the rear 1.5" and the front .75".

*So what suggestions on ride height? If there is no rubbing, is 1.5" lower in the rear too much along with .75" lower in front?

*How do I adjust corner weight to get equal cross-corner weights? Do I have to buy any additional parts to be able to adjust this?

Thanks again to all for the great info shared on this board!

John

davidfarmer

The alignment sounds great, but you may find re-aligning a pain. I would suggest considering comprimise, about -1.75 front, -1.0 rear, and just leaving it. This won't wear your street tires as much as you might think.

As for ride height, I think that is too much in the rear, but see how it handles. I haven't looked at the 19" tires you mention, but check the diameter. Anyway, measure the "rake" along the frame-rail, between the jacking points. As long as it is level, or slightly higher in the rear, you are fine. ***T1 racers have discovered the cars handle better at OEM ride height, the suspension geometry just doesn't do as well when lowered***

The only thing you need to make your suspension fully corner-balance "able" is at least one adjustable heim link on each sway bar. You need to disconnect the bars, balance the car on scales, then adjust the bars so that they are neutral. While on the scales, you simply adjust the height adjusters to balance things out. I usually jack which ever rear corner that is "light" up. The rears are easier to get to than the fronts when sitting on scales. btw, unless things are waaayyy off, you won't make enough adjustments to noticably change the ride height, so don't get too uptight about the changes. If you do end up jacking (for instance) the right rear way up to get the numbers to match, you can always lower it and raise the front left to compensate.

I'd be happy to help if you were on the east coast.

jlvink66

Thanks for the info David, this helps a lot! I made my own camber/tow plate tool similar to the Hardbar setup. Along with a Pro 360 digital level that I bought and the Hardbar camber kit, I'm hoping that it won't be too much of a pain to switch between street and race alignments doing it myself.

I guess I need to hunt down some heim links!

John

AU N EGL

If your only doing 2 or 3 track weekends a year then changing the camber plates back and forth is not too bad. But 5 Plus weekends, that camber plate change and other prep before and after a track weekend takes too much time. a day prep and a day to return to street set up.

davidfarmer

I didn't realize you were so comfortable making these changes. Yes, the camber part is pretty easy, but getting the toe and thrust angle back is tricky. Even if you record every flat (1/6 turn) you make, it still drifts over time.

I personally find that I prefer just leaving it track trim. The new Z06 alignment allows up to around -1.5 camber (maxing out the OEM tolerances), which is pretty good for track and street.

jlvink66

I'll probably be doing about 8-10 track days this year. You guys are probably right about it being too much of a pain to swap alignments after each track event. I'll give it a try the first couple of times and see if I can get a system going that makes it quick.

Gary Hoffman suggested getting the alignment set up the way you want and then gluing together and color coding the set of camber shims for track and street. Likewise for the toe-in adjustment, paint a stripe on the adjusting threads for the track and street setup. Sounds good, but still might be a pain-in-the-***.

gkmccready

What is OEM ride height? I have 5in to the ground at each jacking point on my C6 Z51... every bit of advice I've gotten is to lower it "atleast" 3/4in and keep 0 rake. Before messing too much I'm waiting to figure out what wheels+tires I'll end up with at the track this year since they are likely to be not-quite-stock sizes.

ghoffman

I am planning on going to the Jan 27-28 Spring Mountain event. I would be happy to personally walk you through this if you can make it.

jlvink66

I measure about 4-1/2 inches to the aluminum frame rail at the jacking points all around when I maxed out the lowering on stock front bolts and after removing the rubber grommet on the rear bolts and maxing out the adjustment.

Can anyone explain why when I measure the left front it's 1/8 higher than the right front when measured at the jacking point, and when I measure to the fender well opening, I measure the left front 1/2 inch lower than the right front??

John

jlvink66

Thanks for the offer Gary, but I'll probably not be able to make it.

John

0C5stein

It is more important to get the cross cornerweights balanced (for all around handling) than it is to have an absolutely level frame. If your frame is only 1/8" out of level then I wouldn't worry about the measurement to the fender opening.

A standard cornerweight and 4 wheel alignment is $275. Swapping in some adjustable end links isn't a big deal seeing that you need to disconnect one end link in the front and one on the rear to properly cornerweigh a car anyways.

Our shop is about a 2 hour drive from Santa Rosa so add another 20 minutes from Healdsburg. (I used to live in Windsor). My guess is that you will be running Sears Point, Laguna and Thunderhill, which all like a slightly different setup, but I'm sure, for starters, that we can come up with something that will work well at all of these tracks. Next year MSI will be offering more track day support, so I should be able to assist you at the track in comming up with the best setup for you and your driving style & skill.

I'll be back in the store on Tuesday, so give me a call.

aTX427

I just purchased poly a-arm bushings, so I am going to re-adjust my car to handle better and have a few questions:

Looking for recommendations on street alignment settings set for spirited handling.

If I don't have access to corner scales, should I try to level the car at each corner or set it up at an angled rake? (can anyone in Austin counter weigh the car?)

Do I need adjustable heim links on the sway bars or just disconnect the stock parts when I do the adjustments?

What shocks would you recommend? I have a z51 with Z06 springs and sways.

Thanks in advance. - John

Norm_427

Same here. When I measure ground to jacking point on frame for both fronts and they are both even there, then the wheel gap on the LF is noticably greater than the wheel gap at the RF. ? I don't think the wheel gap is important, but still makes me wonder if something is catty-wompas.

Norm

davidfarmer

cars are imperfect machines. Each body panel comes out of a mold, and "sets up" differently. Same for the hydroformed frame, the aluminum sub-frames, etc. If you get the front level, the rear will likely be higher on one side. Or vice versa. Get it as even as you can, and live with it.

If you aren't corner-balancing, then no reason to bother getting adjustable end links for your bars. Fortunately, all C5/C6's have adjustable spring mounts, so corner balancing is easy.

Back to the original post, you'll find -1.75 front and -1.0 or so rear will give 90% of the grip of the more aggressive alignment, and still give tolerable tire wear on the street.

I do my own alignments, and can do them quickly, but changing them EVERY trip to the track is just not worth it.

trumper Z06

Alignment... Hhmmmm... also depends on the tires you are using !!!

It's important to consider that too !

hapnermw

I'm using max Hardbar camber plates front and rear with VB&P offset front upper A arm poly bushings and Baer toe links. I've replaced the OEM upper A arm bolts with Hardbar studs.

Once the car is properly aligned and corner weighted, this allows fast and accurate switching between street and HPDE alignment by swapping toe link shims and flipping the front poly bushings (rear camber is left the same but rear toe-in is increased for the track).