Pazzo009

Hi guys, I'm just curious if anyone has done this. I can appreciate that the engineers at Porsche thought that a 245 would be ideal for this car. I do not tend to tamper with designs, but I'm curious to see if others could elaborate on this question

916Bob

Some thoughts to consider...

- unless you also reduce the aspect ratio (width to height), of the tire, you will end up with a larger rolling circumference, and thus increase the ride height of the front of the car. How much this would impact handling is debatable but I doubt it would be helpful.

- the extra width and height of the tire would tend to make it more susceptible to roll over in turns. And thus less grip and less wear. Additional pressure or even alignment changes would not eliminate this effect... only an appropriately wider wheel would. Handling would very likely (if not definitely), be degraded.

- I don't know but I'd guess it might be difficult to find "N" spec (Porsche), tires in this size. IMHO, it is not a good idea to choose other than N spec tires, especially for the GT3. And you really don't want to mix and match them.

- if you're trying to address a front end push, this is not the way. If your wife bought you the wrong size for your birthday, thank her but send them back and exchange them for the right size.

Randyc151

The 255 are considerably taller than the 245, so the car would lift up in front. Would be nice if we could fit the same tires that the RS has, but we don't have the wheels for it, nor the body panels to wrap around it. Finally, it may throw off the traction control features or even the ABS. Not advised until you get a buddy to try it out for you first with his car.

Pazzo009

Thank you gentlemen. All valid points I did not consider. You've both been very helpful

Tom Tweed

You really need to go down to 19" rims to have some better tire choices, which is an expensive proposition. Look through the threads here on track tires and you will see some possible combinations discussed there. One of my friends is running 265F/325R MPSC2 on some HRE 19" rims and it seems to work well, with enough negative camber to keep them tucked under the fender lip.

TT

Texas RS

The local guys that got PCCBs have found that they are stuck with 20" wheels. The guys with red calipers and iron rotors have a option for 19s, but it is very tight. I think both that I have seen are Forgeline wheels. Others may have an option, I just haven't seen them.

Tom Tweed

Check post #65 in this thread by mipor for 19" Forgeline fitment over PCCB calipers. Tight, with some massaging of brake line bracket to fit, but it looks like it works.

With some more suspension mods, HRE has fit 19s over PCCB brakes here:
https://rennlist.com/forums/991-gt3/...over-pccb.html

TT