CWay27

With the crappy roads I would tend to say the opposite. Just like hardly anybody uses light magnesium wheels on the streets.

Mike Buck

Are these for your 944 Turbo? Any concerns about clearance with the front bearing cap? We need a larger centerhole than a 911 (see special BBS RE's, etc.). What sizes and offsets are you trying?

mdrums

What tires will you be putting on them?

todinlaw

I will put that in my little note book for future reference.

I was going to save that discussion for another thread, I was searching the forums to see what others have done. but What I want to try is the Nitto NT 01. I already have a set of r888 on my 19 inch rims. The reason I went with 18 is to get a chance to try something new. the nitto offers a 245/40/18 for the front but they only offer a 315/30/18 in the rear which is quite a bit shorter in diameter that the 305/30/19's a closer size would be the 335/30/18 but Nitto does not make one. Toyo does but Nitto does not. so I want to make sure that does not mess up my ABS or other nannies. on the car. ( I know, turn off the Nannies)

mdrums

I would like to ty the NT01's too. Lots of 996 and 996 turbo guys at my track have used the NT01's and liked them. The R888 is the trie choice now were I track, Sebring.

I am needing to buy track wheels again. I am confused on to buy 19's or 18's. I had 18's CCW's before and loved them. I just wonder how much truth there is Porsche telling me my car (2009 Carrera S with the lower ride height Sport PASM) is designed around 19's.

Anyone???

todinlaw

I was told the same thing about the design around the 19's but you will have plenty of people on this forum tell you that the 18's work just fine, now hear is some incentive, if you burn up tires. Nitto fronts 245/40/18 =217.00 and 315/30/18 rear 319.00 per tire. Now if i bought the nitto rather than the corsas then I almost paid for the new set of rims.
http://www.performanceplustire.com/p...-18#prodAnchor

RonCT

The problem with the Nitto is they don't make a rear tire size for our 997 platforms. These cars are designed, whether in 18 or 19", to run on about 25.5" front diameter tires and 26.5" rear diameter tires (plus or minus a little). Those diameters come into play regarding speedometer, odometer, ABS, PSM, etc.

Toyo RA1 and R888 make a "Porsche diameter" rear.

As to 18 vs. 19 - Porsche puts 18s on the 2009 997 products, so clearly it's an acceptable tire size.

wbrownie

Run 245 front and 315 rear in either the R888 or Nitto and you'll be fine. No problems with ABS, TC, etc. etc.

RonCT

The R888 in 305 is 26.3" and in 335 is 26" rear diameter, so no problems there. I wouldn't use 315 with the 25.5 diameter... I've been reading and hearing that the further you get from stock diameter, the more potential you have for issues. The car and systems are all designed to about a 26.5" rear tire diameter and it makes sense that if you change that for 25.5, or worse yet 25", you run some risks. RWD is less of a concern, but I would think AWD would be even more sensitive to improper tire diameters.

wbrownie

Have run one set of R888 and multiple sets of Hoosiers at 315 with no problems whatsoever on the GT3. Agree AWD is totally different.

todinlaw

I have been trying to do a search on this forum but so far I must be missing the buzz words, but I swear that people have used the 315/30/18 with out any issues. Obviously you have as well. Did you find that you noticed the difference in low end pick up and shifting points? were the fronts 245/40/18

wbrownie

Didn't really notice any difference in gearing. I ran 245/40 fronts in the Hoosiers and I think it was 255/35/18 in the R888 which was a bit wide.

Do your search on the 997 Gt3 board. Lot's of info over there on tires sizes. I seem to remember that the consensus was to not run the 305 R888. The 315 was more stable.

Daggie

I found this topic, using the search. Since it's not that old, I hope you guys might be able to help.

I own a 2006 997S and I intend to buy 18" OZ Alleggerita HLT, but I don't really know the sizes I need. Right now I have 8.5x19" and 12x19" GT3 wheels.

The 18" wheels should be:
8.5x18" and 11.5x18"?
With what ET?


Tirewise I'm going for Michelin Cup or R888's. (More likely R888)
Rears should be 305/35ZR18? Or 315/30ZR18? Or 335/30ZR18?
305/35ZR18 has an overall diameter of 26.3
315/30ZR18 has an overall diameter of 25.5
335/30ZR18 has an overall diameter of 26

So 305 and 335 should be the best option.


Fronts should be 235/40ZR18?
235/40ZR18 has an overall diameter 25.5
245/40ZR18 has an overall diameter 25.7
255/35ZR18 has an overall diameter 25.1

I have no idea whatsoever on fronts ... Hope someone can help ..

RonCT

Tire Rack's system will show you the offsets you need for your car. 235/40-18 front and 305/35-18 rear appear to match the OEM diameters perfectly. With the RA1 I ran 245/305 and it was very effective and might be what I'd get if I were going 18" R888. By the way, there's no 18" PSCup offering that matches what we need. I'm torn between 18 and 19" myself given that right now for Porsche there are 3 good 19" options (PSCup, Pirelli Corsa, and R888), while the 18" offerings are minimal and dropping - that is if you want to stick with the OEM 25.5 and 26.3" diameters (speedo, odometer, PSM, ABS, etc.).

Daggie

RonCT: I was waiting for you to come with answers, thnx a lot!

I decided to go for 18" as I already have a set of 19" GT3 wheels and a set of 19" Lobsters. If Michelin doesn't offer the sizes I need, I'm definitally going for Toyo. I run PS2 on the GT3 wheels, so I intend to keep those for rainy trackdays. I looked on Tire Rack, but they only suggest 19" or 20" for my car (997 S, not GT3).

235/40-18 front and 305/35-18 rear, thnx, got it