Izzone

What size on RS rad?

I knew you woudl know the answer to this

NJ-GT

245/40R18 and 315/35R18. The rear tire is very wide, the 345 won't fit unless you get a custom wheel with 0.25" more back spacing and roll the rear fenders.

The taller 245/40R18 is a better match when using the 315/35R18.

For every other 997 GT3 (all .1 and .2 GT3), the 245/35R18 and 305/30R18 are a better fit as they help improve gearing.

The 305 and 315 are only 8mm apart in width on a 12" rear wheel.

I put 1,000 road miles, 4 track days and 6 autocrosses on one set of these, they only tire I have used that lasted longer was the RA1, but RA1 cannot touch the grip of the V710.

V710 wear nicely, in some cases they can be as fast as A6, they really stick.

Izzone

I just looked and they are not available on tire rack?

outline

If it helps you run your fun size tyres, speedo comes from rear tyre signal

deputydog95

What about the whole square shoulder vs rounded shoulder thing?

The tire shapes in those sizes don't match. I think the front is rounded and the rear is square. Tire Rack says something about specific tuning may be necessary if you combine different shapes. Any thing that I should be concerned about?

How do they wear? Do they heat cycle out or can you use them till they cord such as in the RA1? The hoosiers make me nervous as its hard to tell when they're done as they signal you by sliding even though there's lot of tread

NJ-GT

The speedo is already off on all the 997 GT3 by 4.5%, so your 150mph indicated speed is just 143mph. Plug a GPS (traqmate, race-keeper, vbox, or even a garmin navi), get to 100mph on the GPS, check speedo, get the truth.

NJ-GT

Rounded shoulder was the original design, these tires came designed for camber challenged cars. Later on Kumho made the square shoulder to put a wider contact patch on the same width tire, but these ones don't work on camber challenged cars.

I found the round shoulder Kumho V710 to be fine at -2.5 camber at all corners, never tested the square shoulder ones as they were not made back in the day. Expect high grip from the square shoulder tires, adjust the car balance with your front sway bar (easier) if it is a little loose.

I ran them hot at 28 psi front and 32 psi rear.

They heat cycle, but you can easily get 24 HC from the V710, which is about 50% longer life than the R6, you cannot run them through the cords, unless you drive long sessions (30 minutes sessions) in which case you won't reach 24 HC, they will cord.

Great tires, but only for cars that can fit 18" wheels in the front axle.

Very progressive at the limits, but the Hoosier has better forward traction.

The Greek

Great info Rad. Deputy and I were talking about this on Sunday night. Good alternative to NT01's

deputydog95

I'd prefer to use the NT01's, but the tire sizes are not correct for our application.

These may be a good option. The different profiles concern me a bit though.

I like the hoosiers but they are a horrible value for the DE guy, have very little audible feeback, and don't over much in the way of a little slide. They seem to be a bit on/off for my taste.

deputydog95

Do you think a 315 would fit? I'm running 315 in the hoosier. I can't find a section width spec on a mounted R6. Only unmounted. Which is about a half inch narrower than the Kumho in a 315 mounted on a 12" wheel (12.9" vs 12.5" for the hoosier)

deputydog95

I think I'm running 3 up front now and 1.5 in the rear with the hoosiers, per hoosier.

Since you like 2.5 up front with the rounds, where do you think you would go with the squares out back?

I still don't really understand how the profile impacts camber one way or the other. Does the rounded inside almost give you camber by nature of the shape?