: Racing slicks for my 2012 CTS-V stock OEM wheels



JSE
04-28-13, 02:45 PM
I have a 2012 CTS-V Sedan. My goal is to run slicks on my stock OEM wheels.

Has anyone tried running the following tire set-up on the stock wheels:

Hoosier R6-
Rear:
295/30/19
Front:
265/35/19

These Hoosiers should fit OK on my stock wheels I think. It appears that the rear diameter becomes 25.97 instead of 26.85 - I think that should also be OK.

Has anyone tried or can anyone confirm this is an OK track set-up?

Thanks

thebigjimsho
04-28-13, 06:20 PM
That would work. However, I'd always recommend a square 18" setup. TSWs in 18x9.5" size can be had for under $1G, shipped. And used slicks in 275/35 18 are also easy to locate and cheap. 18" tires will always be much cheaper since they are exponentially more plentiful...

the blur
04-28-13, 07:54 PM
I too have been looking for 19" R compound tires. Basically there are none in stock 27" OD. I have contacted Hoosier, BFG, Kumho, & Toyo, and I asked them to make a tire for us. I ask you (and everyone else reading this) to go on their web sites, and through the contact information button, and email them.

Hoosier and BFG actually responded to me. Kumho never responded, and Toyo I only asked yesterday. If enough of us ask, they will make a DOT tire for us.

I have the extra set of wheel waiting.

JSE
04-29-13, 08:59 AM
Thanks both for the replies.

thebigjimsho:
1- I had heard that squaring up in the front can slow the car down - do you know if there is any truth to that?
2- 275/35/18 takes the diameter down to 25.58 - is that still OK? Do you know if 285's would fit on the front? 285/35/18 diameter would be 25.85 - might be better? Not sure if those are as readily available.
3- I had heard that slightly smaller diameter will slightly improve acceleration - have you noticed a difference?

the blur:
I do not think that anyone makes a slick for a 19" wheel that gives you a 27" diameter. The ones I found from Hoosier give you a 26" diameter. Do you mean that the 26" (295/35/19) are not in stock?

Or, by "DOT" - do you mean a tire that you can drive on to get to the track becasue it is street legal? Of course, slicks are not street legal, but Pirelli makes a DOT tire that fits exactly - OEM size - Perelli P Zero Corsa's.

the blur
04-29-13, 09:04 AM
DOT and R compound tires are the same thing. They have some tread, just bearly enough to be DOT legal.
The P Zero Corsa's are $2000 for a set, and tirerack is closing them out. Which may mean they are old and out of production. Not sure.

JSE
04-29-13, 10:58 AM
I just got off the phone with Tire Rack - Hoosier R6 are readily available in the 19" for a stock wheel staggered set-up on the V:

Rear:
295/30/19
Front:
265/35/19

the blur
04-29-13, 11:03 AM
Those are smaller in OD, than the OEM setup, which is 27"
Also, the 295's call for 10" wheels, which are not available on the sedan.

JSE
04-29-13, 12:46 PM
Yes - slightly smaller in diameter:

The stock tires are 285/35/19 which is a diamater of 26.85. This setup for 295/30/19 is a diameter of 25.97. This is only a 0.89 variance - or about 3%. This will be fine - speedometer will be slightly off (for exmaple, at 60 miles per hour on the speedometer - actual speed will be just over 58 mph). There should be slightly improved acceleration becasue the diameter is slightly smaller.

295's will definitely fit on the 9.5 inch sedan rear wheel with no problem. And the 265's will definietly fit on the 9 inch sedan front wheel with no problem.

thebigjimsho
04-29-13, 10:27 PM
Thanks both for the replies.

thebigjimsho:
1- I had heard that squaring up in the front can slow the car down - do you know if there is any truth to that?
2- 275/35/18 takes the diameter down to 25.58 - is that still OK? Do you know if 285's would fit on the front? 285/35/18 diameter would be 25.85 - might be better? Not sure if those are as readily available.
3- I had heard that slightly smaller diameter will slightly improve acceleration - have you noticed a difference?

the blur:
I do not think that anyone makes a slick for a 19" wheel that gives you a 27" diameter. The ones I found from Hoosier give you a 26" diameter. Do you mean that the 26" (295/35/19) are not in stock?

Or, by "DOT" - do you mean a tire that you can drive on to get to the track becasue it is street legal? Of course, slicks are not street legal, but Pirelli makes a DOT tire that fits exactly - OEM size - Perelli P Zero Corsa's.

I didn't notice any ill effects with 275s up front. 285/35 would be even better, but they're harder to find. 275/35 are everywhere...

the blur
04-29-13, 10:45 PM
As I mentioned above, contact all the tire companies, & let them know we need more tire choices for our cars. Toyo responded to me today, and said they will pass it up the chain, but obviously there needs to be a demand.

A smaller OD will hurt top end, and top speed. The motor will be revving higher for no real reason.

JSE
04-30-13, 01:11 PM
Personally I am not worried about top speed - I am not planning on doing 190mph. I get up to about 155mph on the long straightaway at my home track if I push it - and that is plenty for me.

Really the diameter being off by 3% will not make a material difference. I spoke with Hoosier and they said that you can indeed squeeze the 295 on the rear sedan wheel (which is 9.5"). Alternatively you could run a square setup with the 265s all around. That would make the rear diameter even closer to original. Instead of 26.85 (original - 285/35/19) it becomes 26.3 (265/35/19). This is only a 2% variance, and the 265 will fit perfectly on all 4 OEM sedan wheels.

The setup is as follows:
OEM reasr wheel 9.5 inch - with Hoosier R6 265/35/19
OEM front wheel 9 inch - with the same Hoosier R6 265/35/19

ctsvracingalan
04-30-13, 08:53 PM
I have been running a square set up with R6s 295/30/19 on 2009 sedan stock rims 19-9.5 (rear) tire pressure is key for this set up our cars are over 4000lbs and you must run 43-48 hot. I have lived this for years and I can assure you it work best. If you would like to discuss further feel free to call me

the blur
04-30-13, 09:00 PM
I'm running the factory tires this weekend. The rears are full tread, the fronts are 50%. I'll let you know what I think. Obviously I won't be pushing it on street rubber.

thebigjimsho
05-01-13, 07:44 AM
I'm running the factory tires this weekend. The rears are full tread, the fronts are 50%. I'll let you know what I think. Obviously I won't be pushing it on street rubber.

Pump up those fronts...

the blur
05-01-13, 07:45 AM
What pressures do you run in the OEM tires ?

thebigjimsho
05-01-13, 07:51 AM
Up near 45 hot...

the blur
05-01-13, 08:29 AM
great. I'll start at 40.
what do you run in the rears ?

thebigjimsho
05-01-13, 11:42 AM
A little less. Maybe about 3 psi less...