Just thought I would do a small intro here also cause I will be posting a lot in this sections cause I am an avid autocrosser. I am trading in my 2007 Subaru STi that i built for STU for a 2010 Cobalt SS with LSD. I already ordwered a set of 235/40/18 Dunlop star specs to run my local street tire class for the rest of this season.

My plan for next season is to run Dstock on race rubber. My question is what size are people running for race tires? I'm looking at going 245/40/18 to start with on the stock 18x7.5 wheel.

Tires offered in that size are:

BFGoodrich g-Force R1 $283.00EA
Hankook Ventus Z214 (soft and medium) $275.00
Hoosier A6 $292.00
Kumho Ecsta V710 $261.00

For those who are running race tires what size and what tire are you running? thanks for the help!

 

I'm running 235/40/18 on the stock wheels.

 

What tire are you running in that size?

 

I got lightweight 17s on my SS/SC with I believe 225/45/17 Avon Tech Rs.

 

Yeah i am going to have CCW LM20s built for the car in stock size and in a +38 offset. Just checking to see if anyone is running a 245. I seen poeple run a 235 for street tires and i think a 245 race tire will fit but who knows lol

 

Qwikredline runs 245 Star specs on his redline and tracks the **** out of it.

I think he has Hoosier A6's as well, but not sure on the size or wheel.

 

Nitto NT01. Not that sticky, but I'm just screwing around on track.

I did get a touch of rubbing on a liner. I suspect from some wet skidpad time where I had much more steering input than I would on track.

 

yeah the race tires i listed arent made in a 235, only 225 and 245 in coblat size. hmmmm lol to rub or not to rub.

 

My 245 streets rub in the rear.

 

For a dedicated race rubber I'd run a 255/35-18 in an A6. The'll fit no problem with a 36mm offset.

 

holly F... 255. Might have to look them up lol since they are race tires only rubbing isnt a big problem. On the 255s what wheel are you running? stock size?

*edit

wow 255 300 a pop. hmmm lol

 

I haven't run them. But, I know that's what Kevin Dietz ran most of the time and he won the ProSolo championship. I'm going STX next year, I never liked changing tires.lol Ya stock class is gonna limit you to a 7.5" wheel.

 

245/40/18 Hankook RS3s on stock wheels...

Why CCWs (for stock class)? I thought the stock wheels are forged and not every heavy...

 

I think the stock wheel is about 23lbs? I dono the LM20 looks freaking good but you are right.. maybe just go an 18X8 or 8.5 for a nice show wheel.


i see. Hmm well 2011 is going to be a develpment year for me and a few parts i am making for the cobalt. Just to save some money i may run 245 to start.

Stock class sucks but it is quite a bit cheaper. My sti was well built for stu but to stay on top requires a lot of money each year

 

Hmm... whats the confirmed stock wheel weigh anyways? Arent they forged? :P

Personally, I would save the money for CCW when you are about to move out of stock class... you wont
find any wheel over 8" wide in 5x110....

 

No I'm thinking I would get the CCW for a show wheel and switch over to R comps at the track. I wont be leaving stock class in this car cause I plan to go to nationals with it next year. The SS with the mini cooper S are about the only things that can give the ITR a run for its money in DS.

Just cause something is forged doesnt mean they are light, just means they are stronger and lighter than a cast wheel. My BBS stock wheels on the STI are 23lbs.

 

Race tires run different sizes than street tires.

225/40/18 if you're sticking with 18 inch rims, 225/45/17 if you're using 17s

Pretty sure qwik uses 225s, I just can't remember what rim size he uses off the top of my head.

He runs 245/40/18s on the street, not on the track.

 

I just did a HPDE at Homestead/Miami Speedway this past Sat. with the mods in my sig. I've had the wheels and tires on the car for almost a year with zero problems. This was my 1st track day and I'm HOOKED! You can't really appreciate the Cobalt SS/TC till you are knocking on the back door of a 2010 Lotus Exige whose driver won't give you the pass.

 

I have ran both the 255/35-18 a6's and the 245/35-18 v710's. I really like how the kumhos feel over the 255 hoosiers. They make a 245/35 in the a6, but haven't tried them yet. With the 245's-255's and -2.0 degrees of camber I use a 3mm spacer in the front with the stock wheels.

I was at the Blytheville national tour. I ran the kumhos on a extra set of stock wheels. I ended up winning DS aginst a very good driver in a integra type r. Our last local event I put over 1sec on the field in pax I really think the kumhos are just as fast as the Hoosiers, they just need to be the right size for the car...

 

Awesome info! thanks for the help!! I agree on the Kumhos, i ran them on a friends miata and they last a bit longer.

Is there a reason you went 245-35, and not 245-40?

 

Yes, it's a shorter tire so it helps a bit with gearing. Our 2nd gear is really long. Plus with a shorter side wall it feels more responsive, it has a less squirmy feeling to it.

 

i kinda had a feeling from what i have been reading up on that it was a gearing issue and the responsiveness works also.

 

Uh, all this R-comp talk makes we want to stay DS. It's a much better DS car than STX.

David, was 2* all the camber you could get or did that seam to be the sweet spot?

 

Yeah 2.0* is all I was able to get out of it. And actually its 1.98 and 1.99...

 

I was told you can easily get 2.2? Mine is at -1.8 right now.. and my car is eating through those street tires quicker than I like...