: 11 CTS V Coupe Big Tire fitment and track allignment

RD in SD
05-28-11, 09:09 PM
Hello Everyone, new to the forum, first post here, I usually hang out over on the Corvette forum but both of my Vettes are down and I picked up a CTS V last week and it looks like we are heading to the track with it. So on to my point.

I spent a couple hours today fitting my wheels and slicks from my C6 Z06s to my CTSV. What I found is that my front Vette wheels of which I have several sets and combinations of street tires and slicks, all are 18s, some stock at 10.5 wide and some wider Forgelines all seem to work on both the front and rear of my CTSV. I bolted on a set of Piliot Sport PS2s 295 35 18 on the front and they rubbed a little on the sway bar at full lock but no more than on my Vette, still street-able in my opinion but very track-able. It appears that they will come very close to hitting the fender at full compression but just might clear with some rubbing on the plastic. I also put on a set of R6s that are 295 35 18 and (they are about a quarter inch wider) they appear to work as well. I drove the car, hit the brakes hard but did not hit a big enough bump to fully compress the suspension. So the question is how big a tire can I stuff under the front without bending my fenders. I don't mind a little rubbing as this is a track set up.

In the back I played with my rear set of Z06 wheels with 345 pilot sport tires. with a 1/2 or maybe a 5/8" spacer it looked like they would fit with some rubbing. With the front Vette wheels in the back the offset appears to be perfect and there is room for more tire than a 295. I would say that a 335 35 18 would be a perfect fit on my stock Vette front wheels for the rear of the CTSV. Has anyone tried this and how big a tire can I stuff under the rear? Again I don't mind slight rubbing at full compression or trimming plastic to get clearance is OK too.

Does anyone know what is the max variance between tire sizes that I can run front and rear without screwing up the computer/active handling? How do I turn off active handling?

At the track in the Vettes I usually run about 2.5 degrees negative camber in the front, about 1 degree rear I think it is, with some toe in for good turn in. Does anyone have any experience with track alignment on the CTSV coupe and what works best? Does anyone make a camber kit for it? Do I need one?

Does anyone know if the tire pressure sensors are the same for the Vette and the CTSV?

I am headed to Chuckwalla this coming weekend is anyone else going (its in the Southern CA desert).

Oh and its a black diamond edition with saffron interior if anyone cares.

Your feedback is much appreciated.

05-28-11, 09:18 PM
many posts on here of the same topic. I run the stock c6z rims on my rear of my v. 305 is the max I would go.

wider then the 305 equals rubbing.

You won't fit anything wider on your v unless you use spacers or want rubbing.

TPMS is the exact same. Just bolt em on and the V will read.

turn off the active handling by the TC button on the steering wheel. Push and hold till u see it on the DIC.

RD in SD
05-28-11, 09:32 PM
I don't mind some rubbing usually like on my Vettes it just means trimming some plastic. Has anyone done this and where are all the threads I searched but could not find anything on this.

05-28-11, 10:14 PM
on ls1tech a vendor tried to put the c6z 325's on the back and ended up destroying the rear quarter panel.

I personally feel you could get some 325's on there with the right off set, but it would have to be a custom wheel.

the other issue is our rims are 9.5, and the corvettes are 10's right (i forget) anything wider on the rim and you have to grind the a arm like cblove did with his rims.

If you find info out otherwise please post and let us know.

05-28-11, 10:16 PM
most of us run the front c6z rims on the rear, it's an 18" tire and then we put the MT 305's on there. I have this set up and it already sticks out about a 1/4 of an inch... not sure how much more I'd want to risk it....