AllanJ

Really? I've ordered two sets over two years and both times 11" were recommended for the rears. 12" was for the 7-GT3.

Cheers,

Steve B in SD

I guess they've recently revised they're preferred setup. All I know is John at CCW says he sells mostly 18x12 with 9" backspacing for the 996GT3. For 997 GT3, he specs 18x12 with 9 1/4 backspacing.
This was as of a couple of weeks ago.

But, as VA122 points out: ....."I use the cup offset and i find it works best for me it's 15mm further outboard. to each his own. " This confirms both that the factory 17mm spacers would work, as well as the Fikse wheels in question. Essentially, the Fikse wheels are almost Cup specs, it would seem.

and, I'm not in a "tizzy"... just having fun...

NJ-GT

Playing with offsets compromises the suspension geometry.

Porsche sells two types of spacers for the 986/996/987/997:

1) 5mm spacer for more aggressive look
2) 17mm to fit narrow body rear wheels on wide body cars.

The 17mm spacers are not intended to be used on the narrow body cars.

Using Porsche 5mm spacer as a guideline, one can run wheels at -/+ 5mm offset from stock safely, regardless of width.

Front: 35-45 offset with 40mm being the stock offset.
Rear: 58-68 offset with 63mm being the stock offset.

I ran 10"/12" wheels with my 996 GT3. The rear were made on the stock offset. The car was running 335 Hoosier/RA-1. The front wheels needed to be at 33mm to fit per my measurements (I actually ordered them using back spacing measurements).

With just 7mm off from the stock offsets, I had some problems with the front wheels gaining more bump steer than before, it was a matter of extra suspension travel for the same loads, plus the additional weight on a 10" wheel. I fixed this by running a stiffer spring, and later on adding a steering rod with bump steer adjustment (the bump steer was there, the wheels made it worse).

51mm offset is to far from stock. At one time I put 11" wheels with a 45 offset, but the car felt floppy. These were 996 Turbo wheels I bought to run scrubbed slicks. I sold the wheels 1 month later.

Steve B in SD

Good info, thanks.
Again, the original question was whether they would fit, or not.
He didn't specify what his actual application was going to be. Now, if he's going to track the car, then your observations would be very helpful. You ran 11" rears with 45mm offset, and said it felt "floppy". Was this with everything else stock, or? There's a lot of variables involved, and depending on the intended use, and other factors, that will dictate what wheels are appropriate.

My only argument was the flat statement that they are "wrong", "improper", and won't work. I was simply answering the fitment question.
You had 10" fronts, and had a bump steer problem. That is aggravated by ride height as well. Is his car lowered? Is his suspension stock? Is he going to track it? Is it a street car?
Lots of questions that weren't posed, that we're all arguing.

Will the wheels fit? Yes. Are they optimal for his situation? No way to know since he didn't elaborate on other details as outlined above. If it's a streetcar, at normal ride height, with normal alignment, with 295/30 tires, they will work fine.

Those are my assumptions used to answer the original question. It's that simple.

Not a big deal!