Hey Guys,

I'm looking to pick up a set of 991 GT3RS wheels for my Turbo S and i'm getting conflicting information from everyone, so please help.

I currently have the center lock Turbo S 20's that are 20 x 8.5 +51 front & 20 x 11 +55 rear.
The GT3RS wheels are 20 x 9.5 +50 front & 21 x 12.5 +48 rear.

A rep at GMG told me the offset would not work in the front yet a couple other shops and Newport Porsche told me it would. Can someone please tell me what the range of what would work on the 991 front & rear is so i can figure it out?

Lastly, i've been told having a 20/21 set-up isn't recommended for an AWD. The GT3 (NON RS) has the same wheels in 20 x 12 +47mm for the rear that i can use to balance out the car. Would ANY of these options work for me?

Thanks in advance.

 

Actually the TurboS CL wheels are 9x20 ET51 and 11.5x20 ET56

GT3 12X20 rear wheels will work. Not sure about the RS front, there is 5mm less inner clearance. Do you know anybody who owns an RS that would be willing to let you test fit?

Another issue is are either GT3 or RS wheels sold separately? Usually sold in sets of four?

 

I know a friend with an RS, but wanna see if it'll work before bugging him.

BTW how could it be that the GT3 has a bigger rear tire? The NON RS are not a wide body like the Turbo S, how could they fit a bigger wheel with a more aggressive offset than the wide body?

 

The tire specs are the same... Only difference is the rear wheel width and ET's but the track width of the turbo rear is actually over an inch wider...

Turbo S
9x20 ET51 245/35ZR20
11.5x20 ET56 305/30ZR20


GT3
9x20 ET55 245/35zr 20
12x20 ET47 305/30zr20

Turbo track width fr/rr 60.6/62.6
GT3 track width fr/rr 61.06/61.22

 

Certainly there are tire options that would allow you to run a similar F/R rolling diameter even with a 20/21 wheel. 21" rear tires does reduce your options for which tires to run... but perhaps that will improve over time.

A random, but potentially useful piece of information is that I did about 3 hours of measuring stock wheels/tires vs. fenders and offsets and ordered an 8mm set of spacers (front and rear) for my specially ordered 5-lug TTS to line the wheels and tires up perfectly with the fenders. I've had a few center-bolt race cars and I have no desire to have that feature on a street car.

Unfortunately, I don't know of any spacer options with center-bolt wheels.

 

Does we know if the 20x12 ET47 would clear the brakes? What does the offset move by every half of inch?

 

The offset has nothing to do with brake clearance. The inner diameter of the wheel is more relevant to that and if it clears the GT3RS brakes then it will clear the turbo's brakes.

The offset moves 1/2 inch for every 1/2 inch

- Patrick

 

since the offset seems to be measured in mm, 1/2 in = 127mm

 

Make that 12.7mm vs 127mm

 

Yep that too!

 

Perhaps this will help...

http://www.willtheyfit.com/index.php...et2=47#content

 

Found the below photo. I see a couple things:

1) the Turbo S wheels FIT on a GT3, meaning the GT3 wheels would fit on a Turbo S
2) The Turbo S wheels look like they aren't as aggressive as the OEM GT3 wheels judging by the rear gap.

What do you guys think?

 

Boss works all day long we run those offsets on both turbo and gt3rs bodies which are same bodied cars. The GT3rs tires is the issue here as they are staggered diameter wheels and your AWD you will need to match rolling diameters which means your front tires will look taller than your rear tires via side wall. You'll need 255/35/20 front and 325/25/21 rear to keep you with in correct rolling aspect ratio and will look goofy with bigger side wall tires on front .

 

Thank you for the reply!

Do you think the GT3(NON RS) 20's would fit in the back? I wanna stay at 20's all around and don't like how the rear of the GT3RS sits higher so if i can get away with the GT3 front/rear or GT3RS front and GT3 rear i'll be happy.

Please let me know if in your opinion/knowledge based on seeing what offsets and wheels on a daily if the set up will work. I (along with a couple other forum guys who want to do the same) appreciate your customer service.

 

In that picture, it appears as though the wheels are tucked further into the wheelwell. It could be the angle, but that is what I see...

I'd go aftermarket with wheels all at the same diameter. This car wasn't designed with staggered wheels in mind, so why break your head trying?

With A/M wheels, you have many varied choices, and you can get exactly what you're looking for!