FTS

I am pretty sure you are right, I do expect it to be the case with 265/305 set. Since this is my first 911 that I'll be on the track with, my learning curve is steep. And since I decided to go with 19" wheels, my issue is with the shorter tire walls. They break away faster and with less warning. So, come to think of it, may be I should just start with 325s in the rear. Decisions, decisions... LOL

Good to have these problems though

Todd B

In looking at R6's, the 325 needs a 13" rim. Would this fit on a GT3? I'm still trying decide on 18's or 19's for track wheels.

997gt3north

The 235 and 265 Hoosier A6/R6 have the same width, the 265 is just taller (something you don't need for the light front axle). The 315 and 325 are the same width as well, but the 325 is taller. Don't trust the specs from the Hoosier website, they are not accurate.

I have used all the available sizes of 19" Hoosier A6 (R6 is just a harder compound), 235, 265, 295, 315, 325, 345. I measure them off and on the wheels, and keep the data.

The 235 Hoosier is actually a 255 tire, the 265 is also a 255 tire (not always Hoosiers are wider). Now the 255/35R18 that's one very wide tire, it really is a 275/30R18.

You should run 235 and 325 R6 (high speed tracks) or 235/315 for short tracks, autoX, ProSolo, etc. The 235 is wider than the stock RS 245 MPSC, and the 325 is narrower than the stock RS 325 MPSC, so less understeer.


The above information is a quote from NJ-GT (Rad) from a post you can find by searching 265 R6. Pretty much gives you the info you need.

Paul

utkinpol

look up info in this thread.
http://www.renntrack.com/forums/show...rs-in-a-NB-997
all i can say - go figure... i will just keep trying experimenting myself.

I cannot see how people can run on 235/255 tires on a 997 cup.

265 is a great front option for 9" rim but again problem is with DOT tires availability in this sizing.

Carrera GT

I chose the 265 to maintain the ratio front:rear of rotations per mile just in case it affected PSM or ABS.
I used this local Hooters retailer -- the service has been top notch.

http://www.hoosiertirewest.com/brows...dial/2,34.html

Todd B

Here's an offset calculator I found. http://www.1010tires.com/wheeloffsetcalculator.asp

According to this the 9" RS wheel with 47mm offset (OZ wheels) would be 12mm more outside then the 8.5" rims on the 3, inside distance would be the same. Might be time for fender extensions?

FTS

Thank you Todd. It may still fit with -2 camber up front. If inside clearance is the same, then that camber should not cause issues with the strut/spring.

Thanks,

wurlie

As has been said in post #9.
The front fenders are the same on both the GT3 and RS, the plastic extensions are stuck on.
Best, w

Todd B

That is true, I guess my point I was trying to make is that the wheels will stick out 12mm further, this the extension would be needed. I still have the stock alignment on my 3 ( I haven't had the car for a month yet), and the wheels stick out a little now. As FT states with more camber, the rims will tilt in, so sticking out shouldn't be an issue.

wurlie

Todd - sorry if I came across rude.
I am planing to install the 9" front wheel in RS offset on my 2010 GT3 so am very interested in the topic, and am sure that there will be no need for the fender modification.
Best, w

Carrera GT

According to Hoosier and Tirerack, the 325 an 345 are measured on 12 and 13 inch rim widths -- being recommended for 13 is interesting, but not mandatory. I have had both tires on stock 12 inch rears with no heat/wear distribution problems and the tire looks "right" (square on the shoulder, not convex or concave on the tread surface.)

http://hoosiertire.com/rrtire.htm
http://www.tirerack.com/tires/tires....r&tireModel=R6

10 GT3

Absolutely. Same front suspension and same fenders on both cars. The tacked on fender flares are only there for stone protection on the RS. behind them is the same fender that comes on all 997s, including a 997 Carrera. If you like the tacked on flares, you can buy them with the matching wider corner lights from your local Porsche dealer's parts department and they can be put on any 997 from a Carrera to a GT2. They are not a requirement to fit a .5" wider front wheel and tire.

utkinpol

So what exactly has to be changed to make 10" wide front wheel to fit in front and make it dive in behind the stock fender? Has anybody got that done with no rubbing?

FTS

Thanks to Al, I was able to do a test fitment of 7 3RS wheels from HRE that has the stock size and offset on my 3.

This is how the stock setup with 235/35/19 tires look like:


This is how Al's HREs are with 245/35s on:



So, as it can be seen the 3RS wheel/tire combo sticks too far out and there is only about half a finger space left on the inside. This is with -2.5 front camber. So, it is a no-fit, so'll be getting 8.5" wheel for the front and stick to 245/35/19 tires.

Here is another shot of how red wheel stand on a white car:


Btw, does this look right to you all?

TRAKCAR

So how's come my 245/40/18 fit fine with 9" BBS and no running?