dsddcd

What is the widest wheel that I can stuff under a 981 Boxster?


It appears that a 9" front and 12" rear would fit with the following spacing:


OEM GT4 (For Reference)
Front 8.5" +61mm
Rear 11" +50mm


What I would Like
Front 9" +77mm
Rear 12" +73mm


The next question, is there are off the shelf wheel that will match?

PorscheAddict

11" rear is tricky to fit on 981's, from what I've read. Your car does not have the same suspension geometry the GT4 does. I'd be very surprised if 12" (and corresponding very wide tires) would fit. 9" front is doable, I think. There are more fitment threads on planet-9.com.

dsddcd

Thanks I will check out Planet9 and see what they have listed. If I could go 9" and 11" I would be thrilled I figured that 12" was a stretch. As a general rule I always try and stuff all the tire under the car I can possibly get.

il pirata

Why?

PorscheAddict

Yeah, these cars don't make nearly enough power to make use of 315's or something out back. It will just add weight and drag. 275/245 would be great at stock 3.4L power (on 10", 8.5").

dsddcd

Simple more rubber equals more grip!

Unless you know what/who your are talking about you should speak for yourself.

Maybe in a straight line but not the case in the corners. If this was the case then there would be no racing series that limited tire widths. There certainly is a diminishing returns but OEM sizes are not near this point.

il pirata

You did not mention which 981 Boxster model you have but the GT4 on a track has more than enough width for me.

You might want to look at a different tire if grip (you mean handling I assume) is what you are after.

dsddcd

It is a 16' GTS with OZ 19 x 8.5 & 19 x 10's off my GT4 with RE71R's. With this setup on the GT4 the grip was good but not as good as the OEM but they were more economical to run.

We recently purchased the GTS for my wife and installled the OZ wheels on it as she did not care for the OEM black wheels. The tires are pretty much shot from the last track day and I was debating up stepping up to the 11" rear which lead me to checking on the front fitment.

According to the "Other9" boards the 11 +43mm will work. If I get time I will pull wheels of each and verify.

Doing some more research the OZ does not offer the 19" in a 11" wide configuration either. So I would either have to go to 20's or stagger using 19's & 20's and I am not sure I want to mess with it.