runabout

Is anyone running the 305/35/18 NT01 the rear or their 996 GT3? Problems rubbing,clearance, etc?
I've got too much negative chamber and inside wear using the 315/30/18 and little clearance on a CCW 11.5 inch wheel.
Thanks

177mph

Thats what I run. No issues. Its close-but no issues...

Martin S.

The 305 tire is about 1" taller than the 315....that 3i5 seems so damn wide, how can it possibly fit? But I am told that it does...I am just staying with the 295 rears, don't want any clearance of rubbing issues. My front and rear negative camber is relatively mild.

Matt Lane

As above, the 305 and 315 both fit, just differently. I have run both.

The 315 is a full 20mm wider, so 10mm inboard and outboard - really not that much, but the biggest issue is that it's a bit pinched on an 11" rim. An 11.5" could only help this.

The 305 is more than anything, an inch taller (so when matched to an also taller 245 front, just over 10mm of impact on ride height. And it exacerbates the gearing (taller).

I have measured my ride height with the 305, and sure enough, adds 10mm of forward rake to whatever you started with - Kussmaul +/- in my case.

I am not a precise-enough driver to tell the difference honestly,

The 305 is a better fit to an 11" rim, the increased rake makes the car rotate better (in theory), if at the expense of the taller effective gearing which, depending on track, may or may not be a big deal.

Bottom line, try both and see if you can subjectively and empirically (factually) tell the difference.

Cheers

Matt

Matt Lane

Back to the OP - when you say you have "too much" neg camber and inside wear, a 305 isn't going to solve that.

As I've learned, even tire wear is not necessarily the best performing (even if it's what I shoot for to minimize my own tire costs). The only way to do this properly is by measuring your tire temps and adjusting alignment accordingly,

I just didn't want to answer your question solely on the basis of "what fits", if in fact there is an alignment issue.

Cheers

Matt

993GT

your toe alignment or worn/soft bushings is cause of inner wear

runabout

The reason I asked is that I thought I would get more even tire wear with less negative chamber on the rear that I might achieve with a narrower tire. I don't think I can reduce the chamber that I have now with the 315/30/18 without rubbing issues more than I have now, which is only slight . I go through twice as many rear tires as front tires now, even though the front tires have a lot more of negative chamber.

AudiOn19s

without this turning into a setup thread (famous last words)... what is your rear camber at now, you said 11.5 ccw rear wheels, what is the rear ride height, are there monoballs in the rear suspension, solid thrush arm busings, etc?

most importantly, are you flipping the tires on the wheels half way through their life?

Finally, what's your driving skill level. When I first started in a 911 I'd go through about 2 sets of rears per set of fronts. It wasn't until I really learned how to trail brake the car effectively to set the front end that I started using up fronts more quickly. Even at best case you'll never quite get to a 1:1 wear rate on this car.