It looks like the little fender flares are stick-on with the regular front fenders.
The tire size went from 235 to 245, but I already fit 255 easy on the front of the 997GT3.

My question; Just gimmick, or do they have purpose?

 

I doubt it's just a gimmick. My guess is either aero or regulation regarding tires extending beyond body.

 

Wider track plus wider rim and tire.

 

Thanks.
How can it be wider when they have the same fenders?

 

The dealer release posted earlier showed a 59.41 front track for the RS vs 58.94 for the regular GT3 - about 1/2". Track is the center of the wheel right? I believe that 1/2" is just the difference between 8.5" and 9" front wheels (1/4" each side). The rear end is different of course but it appears the front is the same other than wheels.

 

According to Porsche ad, fenders are wider: 44mm rear, 26mm front...

Load the video ~ Extreme Truth ~ click on Design

http://flash.porsche.com/microsite/9...ce=16&variant=

 

Yeah but I think in the front, that's just the dimension of the flares.

 

If there is no more room for wider front tires, it is for looks only.
Just a way to differentiate between GT3.

A bit wider track, yes. But could be same on GT3.

 

I am almost certain that stick on flare is to meet a regulation regarding the fenders covering the wheel/tire.

They had to do it on the Cayennes with big wheels/tires also.

The extra track and wider tire probably required the flare.

 

I believe you're correct and C4 panels account for the 44mm on the rear.

Of course, there's the "pucker factor" too...

http://www.youtube.com/watch?v=zZFYv...layer_embedded

 

That makes sence.

Tires are no allowed to stick out. It would be the part of the tire touching the ground due to camber.

 

Wheels width is not related to track. You have the same track regardless of wheel width as long as you use the same offset.

There is either a 6mm more aggressive offset in the new RS 9" front wheels, or new uprights with a 6mm wider hub, or a combination of both to achieve an increase of 12mm front track.

The fender lip is necessary for aerodynamic reasons. When we install wider wheels and tires, even though they fit (I had 9" and 265mm tires in the RS), they create an aerodynamic wall, and they promote lift. The fender covers the top of the wider tire, but the bottom is largely exposed away from the bodywork, increasing both drag (bad) and lift at speed (very bad). It is necessary not to have the tires exposed away from the bodywork.

 

I'm not sure I completely agree with you here. Here's my logic. The track is measured to the centerline of the wheel. Offset is also measured from the centerline of a wheel. To get a baseline you need to first assume a static mounting point (or else there are way too many variables to deal with).

The stock GT3 wheels have an offset of 53, so the mounting pad is 53mm from the centerline. If the wheel is .5" wider and the offset remains constant then the offset is measured from a centerline that is .25" further out which = an additional 6.35mm in offset.

There are several ways to increase track. Spacers, offset, wider wheels, and suspension changes.

 

This is likely a nice solution for track folks - it you don't mind a little front bumper hole or two.

This is an image (not from my car) that is using a Motorsport part to address this issue - tire is a 265, running a spacer and as you may notice a wider front fender

I will likely be going this route this winter.

Paul

 

OK, nevermind - I just drew myself a picture If offset doesn't change then the track wouldn't because the centerline is still the same distance from the hub. My assumption is that the offset of the wheels would change with this or else you would be stuffing an extra 6mm of wheel width underneath the car which may not fit and would certainly not add the benefit of additional track. Anyone have the offset specs for the new RS wheels?