Hi All,

I wanted peoples opinion on which size I should buy. I have a C2S and the standard Carrera S wheel. I know 19's are a little more money for tires. Is there any other reason to run 18's? My tire choices are Toyo R888 if I run 19's and Dunlop Star specs if I run 18's. Any other suggestions?

 

I purchased an extra set of 19 wheels that I put Toyo R888s that I use on the track. I got a good deal on the wheels and that's why I went with that size. I've only had them for a few weeks and did a few days on the track. So far, I'm digging them. Having said that, you're better off with 18s for track.

 

I had 18's but I moved to 19's. I want to put bigger brakes on my car and some of the options won't fit under 18's.

Both are fine for track use.

 

Im in the same dilemma

18": Cheaper tires, more tire options, makes your gears longer
19": Looks better...... (can't think of any more benefits)

 

Actually the correct tires size for the 997 in 18" R comps is hard to find. I ran a 295/30/18, but this size is for the 996. The correct size is 295/35/18. The 19" tires available (R comps) MPSC, Pirelli Corsa, Toyo R888, Hoosier R6. The 19" tires are more expensive, however I think next year there will be more selection.

 

With 18" wheels you would have a taller side wall, a different ride and different steering feel.

You are the only person I have heard of, other than me, that seriously considers the Dunlop Star Specs.

Where are you seeing them sold? I have been using Discount Tire, but none of the experienced track people that have heard much about them.

 

Tirerack has an in depth review. I know some guys that ran them for the 24 hours of lemons. We ran the Hankook Ventus. These are good too.

 

Guys,

I have a few things to add here. First of all, a correct tire on the 18s doesn't change your final gear ratio. You want the same overall diameter. Secondly, I doubt you'll find brakes too large to go behind 18s. I have the big Brembos. 15" with 6 piston calipers. I have 18" HRE C93s and they fit fine. If you get a rock inside the barrel, then it might get stuck behind the caliper and scratch the inside of your wheel. It works great though. Another thing, the Michelin Pilot Sport Cups are great. They work on the 18s and on the 19s. Also, if you want slicks, the options are FAR better on the 18s than with 19s. Having tracked with 18s and 19s (even 20s)... tracked with R compounds, with full street tires, and with slicks, I can tell you that the gummier tire you go with and the smaller wheel, the better. It seems like this question was asked in regards to having a seperate set of wheels and tires for the track. I'll even point out that my slicks (Dunlops) have lasted LONGER on the track than my Michelin Cups (which are R compounds, by the way). And, I strongly suggest 18s. The extra sidewall makes the car more stable, and even more gives you more feel and 'notice' that the car is breaking loose. The thinner, and thus more rigid, sidewall of a 19 doesn't let you know that you're about to break loose as early as the 18s, which is really important on these cars if on any. The 18" wheel is lighter too, and that makes a difference.

Here's my setup. Those are the largest brakes I know of for these cars and they fit just fine. I have 4 sets of wheels right now. I've been all over this block, even with back to back comparisons on the same day. My 19s are Volks, so they're very light as well. So that wasn't even a factor in the difference. I ran those with the R comps directly after the HREs with the slicks. HUGE difference. I lost almost 2 seconds per lap immediately. I hope this question helps some of you. Oh, I'm also going to jump in here and tell each of you to put a Quaife limited slip in your car. It's the best thing I ever did.

 

That's a great bit of advice Blakt. I've been running 19" Champion RS98's and RG5's thinking that the 18's wouldn't clear the Brembo's with 380mm rotors. I've run Pirelli P-zero Corsas, Michelin sport cups and Toyo R888's, but haven't run on slicks. I like the R888's the best in 235 and 305 x 19, though with a wider 18 inch wheel you can go to 245 and 315 provided you dial in enough negative camber. Probably worth noting that you need a properly set up chasis to take advantage of R compound tires and I suspect that you need the full monty like Blakt has to run slicks.

The limited slip diff is definitely a good investment for the track.

 

noob question but when one is switching between 18" track and 19" street setups, should you do alignment after every switch? can one alignment work w/o sacrificing performance and tire wear?

 

Jared, Perhaps the 18" wheels that you are running are designed to work with BBK. I was running a stock 18" wheel and lined a template up with my wheel and I felt it was too close to comfortably run the 18" wheel.

As for the Quaife LSD, it is high on my list of future mods. I also want a LWFW, and a bigger set of binders. I will stay with the 19" wheels as I have about 1 and a half sets of MPSC's to wear out.

 

I didn't have a problem with mine, both sets of tires were wearing very evenly across the tire.

 

The GT3 manual has both a "street" and a "track" set of allignment specs which should work fine for either 18" or 19" wheels since overall tire diameter is very close given the difference in aspect ratio of the typical tires one would use with each rim. I don't change allignment settings between track events, but if you did a lot of street driving with few track events you would certainly get better street tire wear if you re-alligned between events. There are lots of opinions about the "best" allignment specs and if you serch here on on RL you'll get lots of suggested set ups.

 

Could be, buddy. I actually made sure that Dan at Vivid remembered what brake kit I had when I ordered the wheels (I also got the brakes from him). I also did the whole, 'now that I told you, it's your baby if they don't fit'. I saw the wheel order when he sent it to Marc at HRE (since I did the whole custom paint deal too) and it all came in perfectly. So I should revamp my post to say that 18" HREs will work if you make sure that everyone is aware that the BBK is on. Custom wheels are cool. And yeah, do the LWFW at the same time as the LSD. Replace your clutch while you're at it. Save on the labor charge. It's all worth it. I have a race clutch, and while it makes you feel like you're 16 at a stop light on your first date... it's badass on the track. It's amazing the abuse that it can take on high rev downshifts and not give you any problems. So, all three of those all at once and it will change your car more than anything else. Seriously. Your car revs faster, grips better, and takes all the bull**** you can throw at it. I love those mods.

 

I agree with all that Rick said. Also, you CANNOT run slicks without a limited slip. You will snap your diff faster than you can blink... (well, that is if you are running 500HP). Anyway, don't run slicks on a stock open diff. I don't care how good PASM is, it can't handle them. I should have posted that in the first place. And Rick, I wish I heard you say this before I just ordered another set of Cups. Just ordered my 5th set this year. I love them, but would LOVE to try the Toyos if you like them better. Plus, they look cooler and are probably cheaper. Win Win.