Manifold

Anyone have experience with using the RE71-R with the 991 GT3?

In 20", they currently have the correct 245/35 size for the front.

For the rear in 20", they have 295/30 instead of the correct 305/30. The difference in overall diameter is about 1%, which I'm thinking shouldn't be an issue. I'm guessing that 10 mm narrower should also be ok with the rims. Less contact patch in the back may change the balance a bit, but maybe that can be compensated for with tire pressure?

Reports on the RE71-R from GT4 guys are very favorable in terms of grip and longevity, and they cost much less than the Cup 2.

GrantG

The GT3's 12" wide rear wheels are too wide for the GT4-sized 295's (GT4's 11" rim is already the max).

m3irish

Great tires. Unfortunately, you have to go 19's to get the correct sizes. If I had not switched to the RS I would have started running the 19" RE71Rs for the street and track.

orthojoe

I did it. Tires look a little stretched, but they work fine. I haven't posted about it yet because I'm not sure about how they work quite yet. There is mid corner oversteer which delays your ability to power out of a corner, but that could have been because I made a bad call to move the front sway bar from stiff to medium. I will place it back to front stiff and retest at laguna next week. The wear rate looks much better and the wear is pretty even front/back so far.

So far it's promising, but I'm not ready to make the call yet

MaxLTV

Looks very stretched. Please report on results more. I really want to do it.

meaker

Not a fan of the stretch look on a gt3. Also it looks weird that only the rear is stretched

orthojoe

I don't care what it looks like as long as it works on track and I don't lose performance.

Manifold

Is there official guidance from Bridgestone that 11" is the max rim width for the 295?

GrantG

Yes.

http://www.tirerack.com/tires/tires....Potenza+RE-71R

Go to Specs and look at that size. But to confuse matters, the max rim for the OEM Cup2 rear in 305 is supposed to be 11.5" and Porsche uses 12" on the GT3...

Afaik, rim width guidelines are the same among brands (industry standard) and the lower profile sizes typically have different rim requirements than higher profile tires in the same width.

I was was always told to use the widest rim within the recommended range, but not beyond. Maybe there are exceptions to the rule??

stuntman

That's a lot of stretch. The 295/30-20 RE71R only has a 10.7" treadwidth, which is 1.4" narrower than the OEM MPSC2 tires. That's a big difference.

Here's a good read on sizing tires and analyzing treadwidths on tire rack:

http://www.motoiq.com/MagazineArticl...RFORMANCE.aspx

The general rule of thumb is a 0-0.5" narrower tread width than rim width.

Macca

The good news Joe is if they dont work you just throw them on your GT4 and use them up, nothing lost...

I must say the facing side tread-width is 1.4" narrower (and it does look narrower on the stretched tyre) may make for some interesting rear grip on the GT3, but Ill reserve judgement until we hear back from you on this...

452gt3

I just tried RE71R's 265 & 305 19's, did one AX and was very impressed on sign of wear. I then did Spring Mt. and UMC "Millers" back to back weekends using same tires, really like the tires but when they are pushed hard they don't last long I corded the rear tires after three sessions second day at UMC. Never felt the tires going away times stayed consistent, I was very surprised to see the cording. Still feel better trashing corded tires than MSC2's with half the tread left. I will be testing hoosiers next see if they can last as long or longer than RE71R.

Protocav

Mike,
Can you make any comparisons between the grip of these tires and NT-01's...knowing that you probably haven't had NT-01's on this car.

Chad

452gt3

Chad you are correct I have not tried NT01's on this car but from what I remember RE71R does has a better feel much more like a Hoosier but not that type of grip. Will we see you this weekend at Chuckwalla?

Manifold

That's definitely strange. You'd think that Porsche went with the 12" assuming that any 305 tire could be used, not just the Cup 2, and usually it's not an issue to go 10 mm narrower or wider on the tire width as compared to OEM width.