My Dad and I are building a 2009 Mini JCW Hardtop for STX autocross competition. We are trying to figure out the largest wheel and tire combo we can fit on our car. Per the STX rules, the max. wheel width is 9 inches and the widest tire we can run is a 265mm section width. To maximize performance, we want to use the max. tire width but we are not sure it is possible.

Do you know the largest wheel and tire combo we can fit on our Mini with rolling inner fender and modifying the inner fender liner? Also, do you know where we can find a 17x9 or 17x8 wheel that will fit our Mini?

This is the only one I have found so far, but I am not sure it will fit over the JCW brakes - http://www.buywheelstoday.com/produc...20Metal%29.bwt

Thanks a lot for any help.

Here is what the rules state:

14.3 TIRES
Tires must meet the eligibility requirements of the Stock category
(excluding 13.3.F), with the following additional restrictions:
A. Tires may have section widths up to and including the following:
ST, STS, STR (AWD) – 225 mm
STX (AWD), STU (AWD) – 245 mm
STR (2WD) – 255 mm
STX (2WD) – 265 mm
STU (2WD) – 285 mm

14.4 WHEELS
Any wheels are allowed with widths up to the following:
ST, STS, STR (AWD) – 7.5"
STX (AWD) – 8.0"
STX (2WD), STR (2WD) – 9.0"
STU – unlimited

E. Fenders may not be cut or flared but the inside lip may be rolled to
gain additional tire clearance. (The outer fender contour may not be
changed.) Flares that are part of body kits may be attached to the
stock fenders. Plastic and rubber wheel well splash shields may be
modified for tire clearance and to accommodate a rolled inside fender
lip. The intention is to permit fitting the maximum allowable tire size,
and the modifications may serve no other purpose (e.g. air intake,
brake ducts, etc.). No other changes to the stock fenders or wheel
wells are permitted.

 

Despite larger allowance, a shaved 235/40-17 (StarSpec, AD08, RE11, NT05, R1R) type tire coupled with uber lightweight 17x8s. I remember Mach V Dan trying 245/40-17 but don't recall outcome. If you really want 8.5 or 9 inch wheel with 235 or 245 width, you will prolly need custom wheel like the pricey Kodiak Racing wheels or Jongbloed racing wheels. (and a Dremel too)

 

I tried out 245/35R18, which would be about the same diameter as 245/40R17.

It didn't fit -- rubbed the struts in front, so I used 5mm spacers. They then rubbed all four plastic fenders, a lot.

--Dan
Mach V

 

So, 235/40-17 on 17x8s it is.
Guess Mods can merge this thread to duplicate post under Auto-X- STX

 

Thanks for the feedback and sorry for the double post. I figured different people would browse both forums and I would get more feedback. At this point, it is looking like 235s will on 17x8 will be all that is possible, like you said. We still may try to run bigger sneakers because we don't want to start off with a big disadvantage against the BMW 328s running 17x9 with 255 and 265 tires.

There was a Mini that ran a 245 tire on a 16x8 I believe that autocrossed with my Dad, so we are trying to find out what he modified in the fender well and what exact size wheels and tires he was running. It is hard for me to visualize where tire would rub because I am in Texas and my Dad's Mini is in Virginia. I'm helping find parts, etc. and will tune the car, but the car is 1,300 miles away so I can't exactly walk outside and take a look. He is sending me pictures of everything in the fender well that we can modify by the STX rules.

Again, thanks for the input. It helps to know we can atleast run a 235.

 

There are 2 threads that can help you out with proper offsets to fit wider wheels. Keep in mind that R53 and R56 are different 2nd gen has more room. They are not really auto-x or performance oriented threads and most running wide wheels are running super skinny "stretched" style tires on them. You can prolly PM folks for more fittment info.

https://www.northamericanmotoring.co...post-pics.html

https://www.northamericanmotoring.co...de-wheels.html

 

Thanks for the info. You are right, 205s and 215s on 8 and 9in. wheels is pretty much the opposite of what I'm going for but the wheel info helps.

 

I can tell you that 235s fit okay on 7.5" wheels. Not that 8" wheels wouldn't be better, but 7.5" wheels are much more common. The tire is a bit plump on there, but not so much that it feels like it's rolling over all the time.

Here's our own car with that setup, at Summit Point:







--Dan
Mach V

 

Thanks, Dan. Your MINI looks lowered. How much? We will be running KW v3 coilovers so we are probably looking at about 1.5".

Also, what offset are you running on the 7.5s? What do you recommend on the 8s? Getting close to ordering the 17x8s so need a price and availability. (ogburn (at) gmail (dot) com if you want to move to email)

Thanks again for your help.

 

1.25".


+45.

The same.

Still figuring out what's available. Sorry I have not emailed yet.

--Dan
Mach V

 

wahoo5, emailed you!

--Dan
Mach V

 

Thank you very much for the help Dan. My Dad and I appreciate it.

 

Hey I might have just the right wheel for you, I'm thinking of selling my Motegi Trak-Lites 2.0 in 17x8 ET45 soon, as soon as I wear out tires on them, they weigh 13.8 but I removed paint and polished out machined finish so might be lighter. Perfect size to maximize the width of 235/40-17 tire.

 

Sent you an email.