gkmccready

C6 Z51, DRM coilovers, DRM/RD Combo Radiator, Wilwood SL6R front brakes, Pfadt Original Pfatty Swaybars, HardbarUSA Harness Bar & Belt Mounts, Pfadt Poly Bushings. Full, stock interior. CCW C140 18x10+18x11 wheels with Toyo R888s 275/35r18+305/35r18 tires. Almost completely full tank of gas.

Aligned:

Front: -1.8deg, 1/32" toe-in, 7.5deg caster, 4.5" to frame by jacking
Rear: -1.3deg, 1/16" toe-in, 4.5" to frame by jacking

Corner Weights (with 165# driver):

LF 909#, RF 893#
LR 838#, RR 812#

Total 3452# *oink*oink*
Front 1802# (52.2%)
Rear 1650# (47.8%)
Left 1747# (50.6%)
Right 1705# (49.4%)
Cross 1731# (50.1% of total)

We'll see how she feels at Thunderhill Friday. If folks remember I was struggling with tire rub on the fenders and eventually solved it, but I pulled the front wheels in too far and was rubbing the wheelhouse. Yesterday we solved that and re-aligned and balanced. Friday we'll see if we really solved it and are keeping the wheel away from the fender.

I'm pretty happy today. The numbers looks good and the car feels good in street driving...

Bill Dearborn

Not all that bad on the weight considering the driver is in the car. Without the driver we are talking about less than 3300 lbs. Also aren't you supposed to set the weights with a half tank of gas Vs almost full? At 6 lbs per gallon you would be close to 3250 at a half tank.

Bill

gkmccready

So, I thought the half tank thing, too, but RAFTRACER explained to me the last time I posted about this that with the saddle tanks and how the C5/C6 fuel system works you either want to be completely full or completely empty unless you always run with half a tank of gas. Since the tanks are saddled and one side empties in to the other and only then heads up to the fuel rails I guess full or empty gets the best results.

I put a few more miles on the car driving it in to work today and it is feeling really really nice... I can't wait for Friday...

sperkins

Why the toe in on the front?

vette6aut0x

Why the toe in in the front and not toe out?

gkmccready

C5stein and Randy@DRM both recommended toe-in; I set 1/32" toe-in over a year ago and have been very happy with it for my dual-purpose car. I find it turns in just fine, which is where toe-out would help the most. Toe-in adds some stability for high-speed and braking, too, making the car easier to drive. I suspect if I was doing any autocross I'd be leaning towards toe-out in the front.

jacksmonster

Glad to see this note. I have a C6 Z51 as well and I am switching to 18 in wheels all around (cost less). I am currently running 275 35 in front and will run 315 30 in back. I previously ran 305 30 19s in the back and I have not had issues. Also getting LG coilovers.

Question is, do you have to do anything unique to the suspension now that you are running 2 inch smaller diameter wheel/tires in the back?

Thanks a bunch!

gkmccready

Dig up the post that talks about Z and D trim heights; you might want to set things based on those rather than the frame rail heights. I think you'll run into traction control issues (if you run it) with the rear tire being a smaller diameter than your fronts...

jacksmonster

Actually the rear and fronts are both 18s and using a on-line wheel/tire size calculator the fronts and rears have the same diameter.

gkmccready

Check the tire manufacturers claims. Also, for TC to work you need a difference in size front:rear. I show 275/35r18 as 25.6in tall and 315/30r18 as 25.4in tall ... a shorter rear tire will confuse the computer unless you turn off all the TC. Stock the rear tire is almost an inch taller than the front... if somebody would build a 315/35r18 it would sure make us C6 folks happy... run a 315/30 on the front and a 315/35 on the back and still have all the toys at your disposal should you choose to use them.

jacksmonster

Hadn't thought to check with manufacturer specs. Using 1010 tire and the difference on that site is 0.13 inches. I am going to use Toyo R888s and according to their specs it is a 0.2 inch difference (difference may be with decimal round-off).

Think I am going to try and see if this difference affects the TC. I normally always run with it off anyway (except cold or wet track). Another option I guess is to go with a 265 35 in front???