AR1 tyre fitment Z4 Coupe

LemonConnoisseur · Post by **LemonConnoisseur** » Mon May 30, 2022 9:02 am

Morning all!

New to the forum, and not yet an owner of a Coupe as I have a couple of other things to sell first, but I do have a set of wheels that I will be using on the car during the summer months/occassional trackday.

My question is, what size tyre are people managing to fit up front on 17s?

My wheels are 17x9 ET30, so a reasonably aggressive fitment out of the box, and ideally I'd look to run a 255/40 as (weirdly) they're cheaper than 235 and 245 AR1s, with more grip

I don't fancy annihilating the front arch liners, so 255s might be asking too much, but curious to see if anyone has had anything similar on a stock bodied Z4 3.0si.

Cheers

brillomaster · Post by **brillomaster** » Mon May 30, 2022 4:35 pm

i used to run a 245/35/R18 front tyre, though that was on a standard 18x8 front wheel, with a standard 3.0i offset. Didn't have any rubbing on a trackday. looks like a 255/40/r17 has a 7mm larger diameter, so... i reckon the tyre would fit... however, the offset of a ET30 might push the tyre out too far so as to foul on the inner arches. Are you planning on running a lower ride height or standard?

im guessing there isnt such a thing as a 255/35/R17, is there...

another option might be to either buy a standard set of staggered 18s and run 245 front, 255 rear, or maybe even run 18x8.5 front and rear, with 255s all round...

my advice would be to play around with willtheyfit and see how 17x9 ET30 compares to standard 17s... i suspect the offset will be the problem really.

markplant · Post by **markplant** » Mon May 30, 2022 4:38 pm

Might be a daft question but have you tried them , unsure if 17s fit over si brakes, am sure I'll be corrected

Zedebee · Post by **Zedebee** » Mon May 30, 2022 7:03 pm

17s fit over 3.0Si brakes OK, but 16s don’t. 9” is unusual for a front wheel, they are usually 8”. ET30 are usually fine, but in combination with 9”, I have no experience. The arch gap is very large in standard (SE) suspension so you are unlikely to have any problems. More so with Sport or lowered suspension.

mr wilks · Post by **mr wilks** » Mon May 30, 2022 7:16 pm

LemonConnoisseur wrote: Mon May 30, 2022 9:02 am

I don't fancy annihilating the front arch liners,

even with a 235 40 on 9j et 30 i can't see how you will avoid contact

maybe ok tickling it down the road to Sainsbury's but anything spirited that involves a bend or undulating roads & its likely to end in the chaffing of plastic .

For a trial run just add 30mm spacer to a stock wheel like 108 or Mv2 ,

The 40 profile will help a lot but its the area of liner where the reflector is situated where contact is generally made ,

LemonConnoisseur · Post by **LemonConnoisseur** » Mon May 30, 2022 8:36 pm

Thanks for the replies all!

The plan would be BC coilovers, lowered to a suitable height, nothing crazy, with probably -2/2.5 front camber and approx -1.5/2 rear, depending on what I find works well on the road & on track...

Interesting to hear about the point behind the side marker, that is where I was thinking it might rub under heavy compression and turning (ala Nurburgring).

I've seen pictures of Z4MC's on Apex's fitment thread with 255/265 rubber up front and apparently no rubbing, but who knows what the truth is

mr wilks · Post by **mr wilks** » Mon May 30, 2022 9:24 pm

LemonConnoisseur wrote: Mon May 30, 2022 8:36 pm

I've seen pictures of Z4MC's on Apex's fitment thread with 255/265 rubber up front and apparently no rubbing, but who knows what the truth is

The ///M model Z4's run different wheel width , tyre sizes + offsets from factory so you can't really compare what does or doesn't work with a car you haven't got .

LemonConnoisseur · Post by **LemonConnoisseur** » Tue May 31, 2022 9:28 am

mr wilks wrote: Mon May 30, 2022 9:24 pm
The ///M model Z4's run different wheel width , tyre sizes + offsets from factory so you can't really compare what does or doesn't work with a car you haven't got .

The reason I was comparing with a Z4MC is that the shell is the same. There's no bulbous arches like an E46 M3, for example, that accommodates the extra track width.

Having looked online, the lower wishbones are interchangeable between the M and non-M, with the only difference being the offset lollipop bushes... Further research shows that the M uses a different front hub assembly, so whether that accounts for enough of a difference to accommodate that sort of width in the arch without rubbing is to be decided.

I've got a friend who has ET30 Arc8s with 255 AR1s fitted on his E36, so once I manage to get my hands on a Coupe, I'll test fit his wheels all around and see what happens.

Made this thread just to see if there had been anyone with first hand experience on an E86. There's a Pistonheads thread about someone running ET30s with 235s, and that seems to work.

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