Sharing info: Running a square tire setup on a boxster

[JoeFromPA]

Hey all,

I've been looking into running a square wheel/tire setup on my '99 Boxster for a number of reasons. I won't get into them all here.

My ideal size/setup, based upon my own preferences, would be 17x8 wheels all the way around running 235/45/17 or 225/45/17. This would be used solely for street use and daily driving.

I feel like most of the boxster/porsche community scoffs at running a non-staggered setup, or going down below 255 width in the rear. I haven't understood this, as the original 1997 boxster was running 205/55/16 and 225/50/16 tires and the weight and power didn't change for 3+ years and even then, barely changed.

So I've been doing some research and this is what I've found so far:

1. $900 will buy you 4 brand new/take-offs from a Cayman in 17x8

2. RUF Auto Centre built a spec boxster running a square setup of 17x8 (http://inventory.racperformance.com/web/947/vehicle/524388/1999-Porsche-Boxster-Spec-Dallas-Texas)

3. I haven't found any owners reporting that a boxster running the original 16" tire sizes handled poorly, or wasn't perfectly suitable for aggressive day to day use.


Still doing some research, but I'm narrowing down on this setup as a great blend of ride quality, performance, and longevity of tires.

Just wanted to share this...

Joe

[Topless]

No problem Joe. My car originally came with 205/55/16 all around and it worked fine on the street. I would choose that as an ideal snow tire setup as well. With 17s you don't have to even change wheels. Just run 225/45/17 on the 7 and 8.5s as they will fit on both. Larger tires will fill out the wheel well better but if that is not important to you, ignore it.

For unofficial track days I run 255/40/17 all around for max tire life and 4 corner rotation. BSX class requires 225/255 stagger this year so that is what I run for official timed runs. I do find the stagger to be a touch faster.

[JoeFromPA]

Hey Topless,

That's an interesting comment. I haven't considered running wheels that are 1.5" difference in width with the same tire.

Do you know anyone who has done that, even with a 1" difference? I have no experience in that, but i'd imagine that's alot different tire support of the sidewall. I'd think it'd be easy to de-bead the 225 wide tire fitted on a 8.5" rim with hard cornering.

I care about wheel well filling out, but only in terms of if something looks silly. I mainly am concerned with:

1. Reducing sprung, rotating mass
2. Enhancing ride comfort AND the ability of the suspension to soak up mid-corner bumpy roads without skittering
3. Perhaps aiding low-end acceleration a bit with less to spin in the rear
4. Balancing out the car more in the turns
5. Being able to get long-life out of the tires and even tread-wear

I'll check out 225/45/17 a bit more....I'd like to go as narrow as possible while still working great and holding on ridiculously in the corners.

[Topless]

[QUOTE=JoeFromPA]Hey Topless,

That's an interesting comment. I haven't considered running wheels that are 1.5" difference in width with the same tire.

Do you know anyone who has done that, even with a 1" difference? I have no experience in that, but i'd imagine that's alot different tire support of the sidewall. I'd think it'd be easy to de-bead the 225 wide tire fitted on a 8.5" rim with hard cornering. (=QUOTE)


Michelin, Bridgestone, Nitto and Dunlop all say that a 225 tire will fit 7-8.5 rims. I defer to their tire knowledge and expertise.
http://www.tirerack.com/tires/tires.jsp?tireMake=Dunlop&tireModel=Direzza+Sport+Z1+Star+Spec&sidewall=&partnum=245WR7Z1SS&tab=Specs