RedRSA

OP states different sizes than typically used, which is 245/35 F and 315/30 rear. It is possible that he has too much difference in diameter using 235 with 325. Camber also seems to be quite high; while some use this much, avg seems to be closer to -2.5 front and -1.8 to -2.0 rear.

Re pressures, 36/38 hot feels about right and as stated above is on the low side of the range that Hoosier recommends. On courses with high cornering loads such as banked ovals or WG, Hoosier recommends 42-44 hot. I know, that sounds high to me too, but that is Hoosier's recco after reports of high load failures.

997gt3north

It almost sounds more like the LSD to me.

You have some squirely braking - usually LSD (or rotating Hoosiers on rim - which is known to happen)

You are having inconsistent trackout - the .2 car may not like the Guard 40/60 LSD

With Hoosiers getting into ABS?
- almost sounds like tires rotating on the rim?
- or release agent (never had this with new Hoosiers)
- did have it with MPSS and using P50 race pads on the ceramics - it took a full day scrubbing the tires to mostly dissipate the issue

996FLT6

If r6 rotating over rims your should feel increased vibration of car while normal driving and/or steering wheel shake. If guard LSD was done and no such behavior with previous tires I would rule that out. Guard 40/60 pure nirvana no matter what tire u have. If mismatched rear/front tires yeah I can see that. Any video? Mike

usctrojanGT3

I'm not an expert by any means but it may have to do with tire sizing ratios and/or having too much camber (especially in the rear). I've run R6s on my 18 inch wheels a few times with full nannies on and can tell you that the nannies barely come on with R6s versus NT01s/RA1s where I get them coming on more often. I normally run them around 35-36 hot.

Texas RS

I run R6s on my '11 RS with camber -3.2/-2.5 F/R and do not have the issue you are talking about. I do run my tire pressures lower than where you are running and I run 2psi higher in the rear than the front. Starting pressures are 25/27 for brand new tires and warm weather. I typically get about 8psi of pressure increase over a 25 min run. With the rears starting to feel greasy above 37psi.

zweebach

I have seen this happen in my .1 RS with Hooosier R6 and slicks. I always chalked it up to higher grip level tires and slightly different grip between left and right sides of the car allowing one tire/wheel to rotate at a slightly different rate than the other. It did seem to happen at track out of certain corners only. .1 electronics are less sophisticated - traction control, but no stability control. No handling problems with the electronic system off. I personally would probably run a little (~.5 deg) less camber with the R6 (both front and rear) but I'm not sure this is a big enough issue to chase setup changes. Turn off the electronics and see if you need a setup change or maybe there is someone else at your track running same car and tire and you can compare notes.

24Chromium

On a 997.2 GT running Hoosier R6s, shoot for 36F and 38R hot. Otherwise you'll risk the tire tearing itself apart. Ask me how I know. I fully agree with all those who say that anything approaching 30psi is awesome. However, if you want to keep from having a tire explode at speed, run the pressures Hoosier recommends. It feels terrible at first, but take some time to get used to it and accept it for what it is.

Otherwise, do like me and move to Pirelli slicks. Of course, they have their own peculiarities that are hard to get used to. No rest for the wicked.

philstireservice

Most - if not a whole bunch run the Hoosiers way too low in regards to tire pressure. 996FLT6 is the most correct. 30 hot is way too freakin low.....The weight of the car does correlate to the correct hot pressure. Also, whether you want to DRIVE the car or just ride around has a big effect also. If you want to get the most out of the tire and nejoy the true handling of the your vehicle you need to run as much pressure as possible and still have control (which is subjective in the case of skill and comfort). Most guys don't want to push or are a bit reserved in their ability to handle a car at speed.......if you're not going "whoa" once in a while, you're not going fast enough!

Texas RS

My tire pressure recommendations were from the Hoosier engineer. I am not however running I also, only road courses for my RS.

RedRSA

Here is a link to Hoosier's notice I was referring to: http://hoosierracingtire.com/pdfs/bankedovalroad.pdf.

Correction to the pressures stated above; for high load situations, Hoosier says the tires need to run 40-42psi hot.