hyboost

Jorge
Depends on the offsets of the wheels honestly. I know there is a lot of variability in different setups and options from BBS. When I was ordering mine, I had some decisions to make.
But if your rears are same offset as mine (+42), I can honestly tell you that you will need to roll or shave your fender lips with a 305 tire. Stock height might help, but I still think it will make contact with the flat fender lip under full compression. You will also likely need the GT2 liner brackets, but that's a cheap and easy mod. Gives you the needed little clearance on the inside so the tire doesn't rub the lining.

Front not sure, but again depends on offset. I am running 245 tire and have no clearance issue on a lowered car, so likely you will be fine. Other will tell you that 235 tire is not ideal with AWD (neither is 245 but closer to the needed ratio)...but I don't want to open that can of worms up in this thread.

As far as tracking 19's vs 18's...lots of discussions and opinions on that. Tire choices and wheel weight probably will steer you toward 18's...but its not like 19's will prevent you from having some fun out there a few times a year.
(I do have a dedicated e30m3 race car that I've built out over the years and the 996 has and never will see the track..so I can't speak from personal experience on the porsche)

Feel free to email me directly if you need more info. I'd hate to distract from Steve's original post.

Rob
robek11@hotmail.com

Steve Theodore

Just a quick update that I did receive my Forgeline wheels (GA1R Open Lug Cap) for my 996TT and went with the specs provided by powdrhound. It will be a while before they are on the car, but that is because I'm also ordering Ti wheel lugs for this project and PCCBs, as I want to do everything at once. So, at least I've obtained the wheels thanks to your great feedback, and I look forward to pursuing the rest of my modifications as time and money permit (lack of money is always the biggest obstacle, but I'm saving up). I think it will be pretty significant to have the unsprung weight reduced so much at one time, and looking forward to sharing my impressions once it's all done. Thanks again to everyone who participated in this thread...I truly appreciate it.

"02996ttx50

my car on 9" in front plowed, but i'm driving in VERY tight cornering situation ( suggested 15 mph on some ) and RWD. the "thinner" front inch wheel and tire combo "feels" best to me. if i had more wot spaces or tracking to consider, i'd have stayed with a 9 inch front. point well taken.

and congrats on the new setup @steve theodore

1q2w3e4r

I wonder the same thing. I was up at a weekend track event over easter and the Pilot Sport Cup 2's on the front started to delaminate on Friday. I have been running Cup 2's on 235/40/18 and 295/30/18.

I wasn't able to get anything to fit apart from a set of Advan A050s in 245/40/18 so had them fitted up and took it easy to get through the weekend as I couldn't get a matching set of rears. I was worried about the difference in revs and any stress it may put on the front diff though it seems to have been fine (traction light didn't come on) and fitment seems okay. I need to pull the wheels off this week anyway so will look in detail (suspension is stock with some negative camber dialled in).

One thing I did find though with the 245 fronts was the car turned in much better so I actually wonder the same thing, why people don't run a bigger front with the stock rear tyre? Is it the stock wheel widths?

Road King

I'm one of those guys running 235/40/18s with 295/30s out back on 8.5x11/18s. Yokohama AD08Rs. Works great for VERY tight canyon carving similar to "02996ttx50.

I'm also considering 245/40 with 315/30s when my Yoks are done. I still have a 2000-3000 miles remaining, which means another year.

911mhawk

What did you get?
Forgeline and many shops know these cars well enough.

1q2w3e4r

Yeah I agree, the 235/40/18s work well with the 295/30 rears. What I did find though was the turnover was better with the 245/40/18 matched to the 295/30 rear but it seems no one runs this (I only did as I couldn't get a 225/235 40 front at the track last weekend so had no choice. It's significantly taller in the front so doesn't seem like there are any diff issues unless I'm mistaken, the reading I've seen on the diff issue is where the rear is too large, I haven't seen anything the other way (front oversized to the rear).

I'm wondering if I should stick with the 245 front and 295 rear.

Dock

What suspension do you have?

Also, have you driven the same canyons on stock wheel/tire sizes?

Road King

Stock suspension with adj. GMG sway bars.

Yes I have driven several thousand miles on stock sizes on both stock wheels and my current 8.5x11x18 setup on the exact same Western Marin & Sonoma coastal roads - Doc, you would love the drive!

We're talking different tire brands though, so I'm not really making a tire comparison, merely a statement that the larger 235s up front work great for me with regards to my driving style and use case.

Also of note, the Yoko AD08R 225/40/18s are the exact same height (25") and revs per mile (831) as the 295/30s. I prefer to stick with Porsche's spec of having a slightly taller from tire, so the AD08R 235/40/18 at 25.3" & 820 revs per mile matches up nicely to their 295. The 235/40 also fits better on the 8.5" wheel.

Many of the other brands in 225 & 295 do preserve the taller front to rear ratio.

Carlo_Carrera

Good info, thanks.

Dock

Thanks for the information.

My X73 suspension on stock sways and with a bit of an aggressive alignment does really well on the North Georgia mountain curves, including the tight/curvy Hwy 180. Turn in is sharp, and the grip with the Michelins is solid.

I've driven many of the roads in the area you mentioned, just not in a sports car. Beautiful area and phenomenal roads.