IceWater

I'm looking to pick up some 17" track wheels/tires for my 968., Looks like the easiest to find are boxter wheels, but the fronts are 7" and I want to run 225s. Is there a performance hit that comes with running 7" instead of 7.5"?

Thanks,
Tom

Z-man

I have 225/50ZR16's on my 7J x 16 wheels up front. (Stock setup is: 205/55ZR16 on the same wheels). Since the width of a 7J x 17 wheel is the same as the width of a 7J x 16 wheel, you should have no trouble with fitting 225's on it.

HOWEVER, you may have trouble getting the Boxster wheel on your car. With the 1987 & up cars, the offset may be ok, but the wheel bearing cap may cause clearance problems. If you use spacers to get around the wheel bearing cap, you may be too close to the fender. At least that's when I heard discussed at a recent PCA tech by my mechanic. The 993 wheels should fit without problems on your car, provided your model is an '87 or newer.

-Z.

IceWater

Thanks Z. You bring up an interesting point abou the bearing cap. Of course, the spacer would solve this problem. As far as the fender goes, I think I've heard of people running bigger than 225 (like 255) up front on 968s, so it might be OK. Anyone who can chime in on this issue would be appreciated.

Thanks again, Z,
Tom

icat

Here are the two sites I used to calculate my tire sizes when I upgraded from 16" to 17" wheels. The sites will work for any size.

<a href="http://www.dsm.org/tools/tiresize.htm" target="_blank">Tire Size Calculator</a>

<a href="http://www.bridgestonetire.com/products/s03pptec.htm" target="_blank">Bridgestone Tires</a>

Later,
<img src="graemlins/burnout.gif" border="0" alt="[burnout]" />

Exotic HorsePower

I am not sure about the 968 but on my 944S2 I am running 245/40/17 on the front.

Dave in Chicago

I run 205/7 and 225/8 and wear out the 205's faster. Called Michelin, they said 225 on the 7 is actually there preference in wheel size.

Thus, I will be 225 all around as soon as I grind the last bit off of these 205's.

Check with the specific tire mfg specs to be sure. Should be no problem for wheel/tire combo.

Keep the shiny side up,

IceWater

Thanks everyone. The Brigestone site says that acceptable wheel widths for 225/45/17 are 7-8.5", so I should be ok fitting them to the wheels. If Exotic Horsepower is running 245s, I should be OK with 225 and a spacer.

Thanks to all for chiming in.
Tom

2zeroes

IceWater: [quote] Is there a performance hit that comes with running 7" instead of 7.5"? <hr></blockquote>

In my 951, I found that running 7.5 or 8 in the front makes the front end a lot more stable in higher speeds. The steering wheel also feels heavier. I noticed an improvement from 90+ mph. Over 100+ mph the difference between 7 and 8 is like night and day.

Z-man

RE: Performance hit with running wider tires in the front:

It's gotta help a little with the understeer too! You've got more contact patch, therefore more traction, therefore, less of that dreaded understeer our cars have!
-Zoltan.

dave120

I'm not sure about the 968 offset requirements, but the new 996 wheels I just put on my S2 are 17x7" Wheels with 225/45/17s on the front. They clear just fine with no spacers and don't rub at all..

IceWater

2zeros, were you running the same tire width on all those different wheel widths?

Thanks,
Tom

Jason-85944

Don't use spacers on the front! I'd suggest that you just gring down the inside of the wheel in the hub area a little to fit it over the dust cap. That is what I did on my 924S with the Boxster wheels. This part of the wheel is not structural at all. No need to worry about rubbing and spending money on spacers. On the other hand if you choose to go the space route, which I tried I do have a set of 7mm spacers from Performance products that I will sell cheap ($15+$5 shipping). Your call though!

Jason

Tom Pultz

[quote]Originally posted by Jason-87924S:
<strong>Don't use spacers on the front! I'd suggest that you just gring down the inside of the wheel in the hub area a little to fit it over the dust cap. That is what I did on my 924S with the Boxster wheels.</strong><hr></blockquote>Late model Boxster wheels will not fit without a spacer because of the low center cap area, but the older "twist" style (996 type) fit fine.

Jason-85944

They won't?????? You just have to grind on the back side of the center cap a little too! My wheels are 16" off of a 2001 Boxster and are the 50mm offset in the front as well.

Jason

IceWater

Sounds like Jason has some experience with this! The grinding is a perfectly acceptable solution to me (bought that dremel for a reason, didn't I?). I passed on the wheels I was looking at, but I'm sure I'll find myself in the same situation again.

Thanks, y'all.
Tom