Dan Wendling

What are the stock Grand Sport suspension settings?

Wondering how they differ from:

Front
Camber (deg) -1.2
Caster (deg) 8.0
Toe -1/16"

Rear
Camber (deg) -0.8
Toe -1/8"

BrianCunningham

C4 or C6?

or C3 for that matter

Kubs

His profile says C6 so I am assuming thats what he wants. That alignment looks nothing like a stock alignment would, but then again I dont have a C6.

Dan Wendling

The car I am asking about is my 2010 Grand Sport with a Callaway SC606 upgrade.

Bill Dearborn

Although the car has the Z widebody I think it has an FE3 suspension Vs the Z06 FE4 suspension. There isn't much difference between the two. Since it shares the wide wheels with the Z I would suspect the alignment specs may be the same as the Z.

The 08 Z settings are:
Front:
Camber: -1.00 degree +/- .6 degrees ===== VS -.45 deg +/- .6 deg for the 08 FE3
Camber Cross Tolerance: 0 degrees +/- .6 degrees
Caster: 8 degrees +/- .6 degrees ======VS 7.9 deg +/- .6 deg for the FE3
Caster Cross Tolerance: 0 degrees +/- .6 degrees
Total Toe: .1 degrees +/- .2 degrees
Steering Wheel Angle 0 degrees +/- 3.5 degrees

Rear:
Camber -1.25 degrees +/- .6 degrees ======VS -.45 deg +/- for 08 FE3
Camber Cross Tolerance: 0 degrees =/- .6 degrees
Total Toe: 0 degrees +/- .2 degrees
Thrust Angle: 0 degrees +/- .2 degrees

Except for toe the OPs settings are right in line with the Z stock settings and a little above the high end for the 08 FE3 settings.

Right now I can't remember if toe in is negative and toe out is positive or the other way around. I think toe out is positive based on the GM specs for front toe.

Using a 26 inch diameter tire measurement basis 1/32 toe at one wheel is about .06 degrees. 1/16 of toe at one wheel is about .2 degrees. So 1/16 total toe in (negative) the front is about .12 degrees of total toe and 1/8 of total toe in at the rear is about .4 degrees of total toe at the rear. So the front is close to the GM spec but the rear may be a little severe. It really depends on where you are making your measurement. 1/16 isn't as many degrees at 28 inches as it is at 20 inches. That is the advantage of specing in degrees since degrees are not dependent on the diameter of the wheel or the distance between your measuring points.

I used this conversion chart to convert from inches to degrees:

http://www.smartracingproducts.com/p...e_settings.pdf

Bill

wtknght1

Toe in is positive IIRC.

Bill Dearborn

Yep! I just looked it up on Wikipedia. Toe out is negative and toe in is positive. I will remember that for the rest of the day.

Bill

gkmccready

It's heresy, I know, but I actually prefer the way my C6 drives with 7deg caster rather than 8+deg.

Dan Wendling

Thanks for the details.

How can I confirm if the Grand Sport has the FE3 or FE4 suspension? Is there a visible difference that I can check?

What is a good compromise setup for a daily driver that sees 10-12 track days per year? I am willing to live with a setup that is more optimum for the track as I don't drive many street miles per year, and tire wear anything better than 10K per year on OEM runflats is fine.

Bill Dearborn

The suspension code should be listed on your RPO sticker on the glove box door.

I am not sure there is a good compromise. After some help from LG last year when he came to Watkins Glen I had a great handling Z06 that just felt great on the track. Problem was the rear toe in was too much for the street and quickly destroyed my street tires. I cranked back on the toe in and the new tires are wearing better but I miss the feeling I had on the track. The rear end was just planted and I could really get on the power coming out of a turn.

Bill

Dan Wendling

So having two settings, one for track and one for street is not too much trouble if moving between them is simple. In the case of rear toe adjustment, putting a couple of marks on the inner tie rods and writing down the number of turns if more than one would be acceptable changes to make either at the track or at home before and after the event. I suppose that there is a chance of adjusting the wrong direction and really messing up the settings? Could always measure to cross check.

How about running track cambers of the street. Seems like that too would need to have two settings, but with camber blocks it would also be a reasonable track event adjustment.