dbv1

I have a 997 S and I'm thinking about downsizing to 18'' rims for track/autocross but I'm having trouble finding correct size tires in 18''. These are my stock sizes:

235/35R19 front and 295/30R19 or 305/30R19 rear

I would want 255/40R18 front and 295/35R18 rear, ideally, to deal with the understeer. There's no way to find that rear size and the closest is 285/35R18 the only tire available is Hankook R-S3. For the front in 255/40R18, my only choice is Bridgestone RE-71R. If I downsize to 245/40R18, I can also get the R-S3.

Is anyone running 18'' on 997 and what are you running, tire-wise?

mdrums

Yes I did... And if you run 245/40/18 front and 305/35/18 rear....these sizes are the same overall outside diameter as your stock 19" tires.

Or

You can run Toyo R888 ( not as good a tire as the Nitto NT01) and you can run 255/35/18 and 315/30/18. These are wider but smaller overall diameter but they keep,the front to rear overall size ratio in check so that abs is not confused. However I ran this tire and size plenty on times and the Nitto NT01 245/305 sizes were faster and handled better.

I ran Nitto NT01 and found it driveable to the track rain or shine, with awesome grip....best track and autocross street able tire going.

Next best super performance street tire I ran was the Yokohama 008... But this only comes in stock 19" sizes.. Nothing in 18".

18" Nitto NT01 is the best, size for 997's...I prefer this size for street too as a performance size too.

dbv1

Thanks for the reply. Good to know about Nitto NT01 (yup, plenty good choice on sizes). They might bump me into a higher category because of 100 thread wear. R-S3 and 71R are "cheater tires", they're labelled 200 thread wear (so no penalty) but are actually lower than that. I got to talk to them about running 100 wear tire.

I'm not concerned about the rear width, less width is fine because of the understeer. So you liked 245 better than 255 in front? Interesting.

kisik

Yes, 235/245 fronts and 305 rears in NT01s are the best bang for a buck and best performance. R71R are excellent tires but only comes with 285 in rear (which is probably fine). You could also check Yokohama AD08s and old R11s.


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997.1 C2S

mopar bob

Hi I'm running 255 35 18 and 285 30 18 RE71r for SCCA SOLO II. Great tire so much better than the RS3.

dbv1

Interesting Bob.

It seems that with a couple of other upgrades I'll be bumped up anyway so tire doesn't matter, I can pick anything.

Thanks guys.

dbv1

Bob, 285/30 R18 shows 6% reduction in diameter over stock. What is that doing to your wheel position sensors (ABS/traction control)?

mopar bob

Well on what the car is doing I run with PSM off and sport on. I only drive to the track and back with these tires. I run my stock 19's with MSS for DD. It sure helps getting out of the turn for AutoX. I did hit the limiter as I went through lights at the last race for the first time. I run at a mile high so I have less power than sea level. Look at the Rival S 315 30 18 that will fit on a 11" wheel but you only have a 245 40 18 for the front. The GT 3 guys are running the Rival S 315 or the 335's and it's a little taller. The rival is very close in times with the RE71r.
Myself I don't do track days only SCCA SOLO II and it's a blast.

mopar bob

As for my mods I only run a GT 3 with adjustable end links in the front and went to Hawk HPS pads. With the SCCA street class you are limited. I'm looking to move to a prep class next year so I can run Hoosiers. 255 35 18 or 285 30 18 front and 315 30 18 or 335 30 18 back. It should be a blast

Bwk02

I am running (on my 2006 C2 Cab):
- 235/40R18 Bridgestone Potenza S-04 Pole Position in the front
- 265/40R18 Bridgestone Potenza S-04 Pole Position in the rear
Purchased from Tire Rack


No complaints thus far, and close to half the price of MPSS's

ATSR

I've been thinking of going with 18" wheels for my car. I'm planning to use them as the permanent wheels on it, not exclusively for track use (maybe once or twice a year).

The wheels I'm planning to go with have the following sizes:

Front: 18x8.5 46 offset
Rear: 18x11 40 offset.

What tires do you recommend?

I was thinking 235/40/18 for the fronts and 295/35/18 for the rears.

1990nein

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dbv1

Interesting Bob. I run with everything off too, you just don't notice traction control so much until autocross. My track times are very similar with/without PSM but not autocross. Good info on Rival S. I would so love 255 up front because of all the understeer (stock suspension except for GT3 rear sway).

I did some research of NT01, it seems pretty awesome on track but it needs heat to perform. Correct me if I'm wrong please.

ATSR, I would use a separate set of wheels for track/autocross because all the tires we're discussing here wear pretty quickly. I like those wheel sizes, that's what I'll use (OZ Alleggerita). I would go with wider front tires to reduce understeer.

1990nein

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ATSR

Thanks for the reply dbv1

Agreed on using separate wheels and tires for the track. So with the wheel sizes I mentioned, you recommend 245 for the fronts? Keep in mind these will be my street tires (MPSS most likely).