LeMans05C6

Alright guys a while ago I got a 2nd set of C6 wheels in great shape that I planned to put some stickier tires on for the HPDEs. I don't want to go get a nice set of 18s right now just want to work with what i have.

R888s seem one of the nicer tires i can find in a 19" size for the rears.

Would 255/35/18 for the fronts and 295/30/19 work for the rears?

gkmccready

25" diameter vs 26" diameter should keep the computer happy but the front will get lower by about 1/4" and the rear 1/3" simply by virtue of the shorter tires (compared to stock). 255mm front may be a little pushy, though. I'm running 275+305 on CCWs with a bunch of other mods (DRM coilovers, Pfadt swaybars, etc) and the car feels not bad.

LeMans05C6

As long as they will fit the rims OK and I should keep the computer happy I have a lot of learning to do before I really start getting nit picky with tires and the car set up. When i feel i can improve the car and I am not the issue that will be many years in the future.

I had my engine rebuilt so looking to have more traction to keep the power at bay. I know i did it in the wrong order, but as the engine needed rebuilt i figured i may as well upgrade.

rbl

They work quite well but you will be a lot happier buying the right wheels and then you can easily get scrubs for a lot less $$. That will pay for the wheels.

Use 305's and C5 Z06 (18") rear wheels on the back and 275 with C5 rear wheels (18") on the front. You can pick up a pair of after market Z06 wheels for $250-300 and a set of spokes for $200. Good scrubs are $80-100/tire. No alignment issues and the ECU is OK with it. If you don't burn them up you can get several events out of a good set of scrubs. I also use PFC "Z" pads because they stop the car just fine for HPDE and they are rotor friendly.

I'm retiring the car (and me) this year and my stuff will be for sale but not until mid May.

05C6GAC

I've been running 275/35/18 in the front and 295/30/19 work for the rears thee seems to be a little difference the computer doesn't like because I get a active traction message on track out at WOTgoing on to the straightaway? They also like a little more pressure that stock, so if your running pressure sensors like I am when they get hot (and Sticky) you may start geting the over pressure message.

gkmccready

http://toyotires.com/tire/pattern/proxes-r888

255/35r18 fit 8.5-9-10. 295/30r19 fit 10-10.5-11. So you should be fine with the wheel fitment, and the one inch difference is about the same as stock so the computer should also be just fine.

gkmccready

If you're wedging the 275s onto your stock 8.5" front rim they're probably ending up slightly taller than the Toyo claimed 25.7" and the 295/30r19 is right around 26" tall. That probably puts the front and rear heights too close together for the computer to be happy. You probably need to consider 265 or 255 fronts to avoid the computer fits... or just turn off the nannies...

05C6GAC

That's what I've been doing lately, Comp Mode and not reprogramming my tire pressure sensors.

gmccreary

275/35-18 = 25.6 diameter
295/30-19 = 26.0 diameter

I don't think you have enough difference in diameter for the nannies to work correctly. BTW, How's the new engine instal going? I just installed a Spec Stage 1 with an aluminum flywheel. Well, Scott installed it.

jsbwac

This is the setup I have. I got a second set of stock C6 rims, like you did, and did the Toyos. They are fantastic and I have had no problems with the size or any other problem with the car's computer.

LeMans05C6

Thanks for this, it was the type of response i was looking for. Now the question is when do i pull the trigger.

Do i do one event on my street tires with the new power or just start the track right. I am in the 3rd of four groups and was solo approved for the track i am going to but its also going to take some getting used to the new power of the car.

Any thoughts there?

jsbwac

IMO use the new tires. You will like the new tires so much that you will feel like you wasted the day with the stock tires. One thing I did notice on mine when I upgraded the HP and went to the TOYOS, I had to really warm them up as they were very loose cold, much looser than the stock tires. Once warmed up, they are awesome. Also, experiment with adding/subtracting a pound of air between runs depending on what your car does. It is alot of fun to experiment with this and really does make a huge difference (even one pound of air). Enjoy the added HP!

LeMans05C6

Thanks again jsbwac, very helpful and i think i found the best deal so far online.

gkmccready

Speaking of air pressure. Ron @ AIM Tire convinced me to keep adding air to mine and see where I was happiest. I was down at 28#/26# (cold) at the time. I'm now up around 36#/34# cold and finishing around 42-45# hot. The R888s like the higher pressures to get the best grip/wear, every pound I added cold the better the tires felt. And ignore the people who want to tell you to run in the teens for pressure "because the fast Hoosier guys do!" Different tires like different set ups.

LeMans05C6

I went ahead and pulled the trigger to have them shipped. Found a great deal so may as well get the rubber on the way.

Just wondering if these are just put on to drive to the track and back (usually only about 1 hour away) how much track weekends would you expect these to last?

gkmccready

I drive mine every day to work, to the track, to dinner, wherever. There're too many variables to tell you how long they'll last, though. I usually get several thousand street miles and a handful of track days on a new set. YMMV.

DRUGschnorr

i have used 2 sets of 275/35/18 on 9.5in fronts
and 305/30/19 on a 11 wheel on rears
R888 are doing well on a stock 08 c6
the fronts bulge a bit but no messages on the computer, and i kill all AT/TC.. only get a few ABS flashes when i start pushing it at the end of a run..\
keep pressure up, i start at 32 to 33 goal to finish at 38-39..rotate the fronts each weekend has increased life to 4 weekends.
19's are not cheap, so i switched last week to 18 x 10 front and 18 x 11 CCW's and buying scrubs...

Lasco001

On the track, I drive on the Z06 hot 32psi
For me the best grip, because if the geometry is set optmal

On the road I'm going cold 32psi

Lasco001

gkmccready

Just curious, did you try the higher hot pressures and check lap times?

Lasco001

I drive on the Z 295/35x18 and 335/30x18
I start cold with about 1.8 and try to reach a maximum at 2.2-2.3 hot.
In order to reach the best lap times

Lasco001