245/275

[LAP1DOUG]

I normally run 255 Front / 285 Rear, and that size combination works well on track and on an autocross course. This is about the widest fitment that I can make work, and it works very well if sway bars are adjusted accordingly.

There are a few 285 /30 - 18 tire sizes available, but not many at all. A higher up at Bridgestone told me that they will finally be importing their RE-71R in this size within the next few months.

The NT-01 in 245 Front / 275 Rear also works well on my car with the same sway bar settings as my 255 Front / 285 Rear set-up. Obviously if you maintain the same front to rear stagger (in this case 30 mm), you can generally maintain the same balance set-up. As others have mentioned, you have to give up some acceleration with the NT-01 due to the OD of the tire, but that isn't too bad.

The larger OD occasionally helps by allowing you to carry a gear a bit longer. For example at the dip going into Turn 5 at Road Atlanta, I am just touching redline when running NT-01's with a tire diameter of about 25.6" , but I'm starting to bounce off the rev limiter with a 285 / 30 - 18 tire at 25" diameter.

The tire diameter is probably more important in autocross than road racing, as some slow corners can really catch you off the cam.

Have fun.

[The Radium King]

thanks folks, much appreciated. interesting info on the larger diameter - there's one straight into chicane on our local track where i'm faced with either short shifting or bouncing off the rev limiter (depending on how fast i come out of the corner before the straight); having more gear might be better here.

lots of choices; again i appreciate the discussion and info.

ps, if i were to try and squeeze 255/285s in there, what offsets would work? i currently am 1.5" lower w -1.5 front -1 rear camber. front wheels are 8.5" wide ET 53 and from what i can tell a 7 mm spacer should get me 245s, and somewhere in 10 to 15 mm will fit a 255. in the rear no idea; wheels are 10" wide ET 40.

and, not really related, if people are fitting 285 mm wide tires with no issue, and a 11" wheel is 280 mm wide, how come everyone on the internet says you can't fit 11" wheels? is it a coilover vs stock suspension thing? would certainly open up the range of wheels available if we could fit more 996 wheels.

[LAP1DOUG]

Originally Posted by The Radium King

ps, if i were to try and squeeze 255/285s in there, what offsets would work? i currently am 1.5" lower w -1.5 front -1 rear camber. front wheels are 8.5" wide ET 53 and from what i can tell a 7 mm spacer should get me 245s, and somewhere in 10 to 15 mm will fit a 255. in the rear no idea; wheels are 10" wide ET 40.

and, not really related, if people are fitting 285 mm wide tires with no issue, and a 11" wheel is 280 mm wide, how come everyone on the internet says you can't fit 11" wheels? is it a coilover vs stock suspension thing? would certainly open up the range of wheels available if we could fit more 996 wheels.

I have run 255's on the OZ 8.5" et 53 wheels with 7 mm spacers, BUT my car has coilovers and adjustable caster. Without the adjustable caster, you will probably have heavy scrubbing of the wheel liners at anything over about 1 turn of the wheel. Without any spacers looks like it would work without scrubbing according to my calculations, but you may have trouble with clearance to the OEM strut. I can't help you with any data on that, as I have never run the OEM suspension.

I have never done any trials or calculations with 11" wheels on the rear. The general internet wisdom is that it doesn't work, but I think I saw one post where some guy said it worked with just the right offset and lots of negative camber.