Z4 M Definitive Wheel Spec Thread

[dorifto88]

if it is rubbing on the inside why don't you just run a spacer?

Originally Posted by onebluemcm

Update-
So with these wheels and tires on I was getting basically no rubbing under normal road condition but substantial rubbing up front under full compression. Good dips in the road or very hard cornering on a banked tight curve, like the really twisty mountain roads, would result in pretty good rubbing, inner fender liner, front outside edge. I recently got around to swapping my stock springs and dampners for GC/Koni yellows and Dinan springs. I expected the front to rub more, and it does, now over smaller bumps in the road but not the really small stuff. Now the rear also rubs under moderate compression.

The decision is this - sell them and try something else, or down size tires. The suspension is something that I definitely want on the car and I may change it over to a coil over system (GC makes components to convert the struts to coil over). Lowering any more than the minimal drop with Dinan springs may make it rub even with 245/40 and 275/35 tires.

Opinions welcomed.

[onebluemcm]

I stated wrong then, or not clear enough anyway. All of the rubbing is occurring on the outside, not the inside. Up front the rubbing is where the inner liner meets the bumper cover. In back, the top outside part of the tire hits the inner fender liner or possibly the fender lip. I need a negative spacer - the offsets are too aggressive. A smaller tire would help possibly but I think could still rub. I don't want a stretched-out looking tire-wheel combo either - hate that look.

[dorifto88]

Ahhhhh I understand. Well, could you not add some negative camber to push the top of the wheels inside the fender more to clear?

[BBBold]

onebluemcm, do you have biggger pictures of your Z4 ?

and what is exactly the dimension of the wheels you have ?

[onebluemcm]

Wheels are F 9" et38, R 10" et27. I realize that my tire choice is not helping the situation but they are optimal tire sizes for the wheels. That said, these wheels were purpose made for a perfect fit on E46 M3 and were a gamble for fit on the Z4M. My opinion is that the offset is about 5-8 mm too aggressive for the Z4M. On stock suspension it barely works. Any lowering would require a smaller tire and an aggressive alignment, and still might get rubbing. I have the front camber maxed out within what I can do with no camber plates. Honestly, I don't want much more than that because it is primarily a street car that we take on road trips and what not. I'll look for some bigger pics. When you sight down along the side of the car, the outer face of the wheel is dead on flush with the fender or may even protrude out a bit; viewing angle can make it look better or worse. But....I really didn't desire for something that aggressive on this car. What can I say, it was a gamble. The wheels are truly unique and maybe for a different Z4M owner would be the cat's meow, but I think I'm going to move on.

Pics - on stock suspension.














I dunno - every time I step back a look at it man, they are pretty racy looking. Maybe I should try a size down on tires. If I did, does 245/40 front and 275/35 rear sound right? These would have the closest side wall height to each other, and the 275/35 won't screw up the speedometer/DSC too much, right? Hard to decide to spend another $800-900 on tires just to see if it will work or not....

[Beedub]

heeelllppp... will i rub up front with 19x8.5 et32, stock suspension and 235/35/19???

hellpp please guys??

[BlackMoupe]

Would these Style 5's fit Z4M?
http://forum.e46fanatics.com/showthread.php?t=821890

[vortex_tuning]

Originally Posted by Beedub

heeelllppp... will i rub up front with 19x8.5 et32, stock suspension and 235/35/19???

hellpp please guys??

You won't rub for sure.

[BBBold]

Onebluemcm - Your car is awsome. really agressif look.

I'm waiting for my BBS Challenge wheels but it takes 4 weeks

I followed some recomandations around here and took for my Z4 roadster ( suspention Sport OEM bmw) R 255/35/18 not 19" with 10J and ET35 and F 225/40/18 8.5J ET35 from your expirience.. should be ok no ?

[Beedub]

Originally Posted by vortex_tuning

You won't rub for sure.

perfect, thankyou for this... thursday is BBK install, studs n nuts and et32 upfront ;-)

[sho-one]

19"x9.0" +31mm Front
19"x10.0" +25mm Rear

M3 Comp Wheels, I keep getting different answers, Please help. Will this fit a z4 M coupe without rubbing? 245F 275 rear tires.

Thanks all =)

[mfanatic325]

Originally Posted by sho-one

19"x9.0" +31mm Front
19"x10.0" +25mm Rear

M3 Comp Wheels, I keep getting different answers, Please help. Will this fit a z4 M coupe without rubbing? 245F 275 rear tires.

Thanks all =)

Fronts I'm not sure about, but rears should fit fine, as I'm personally running 10.5" +22 rears.

245 fronts and 275 rears are max as far as I'm concerned, unless you do some extra work to fit them; more than just fender rolling and some negative camber.

[Incompatible]

Sorry guys, a slightly OT question. While looking at various wheel manufacturers, occassionally I'll see the restriction "rear use only". I'm guessing that the load rating for that specific width/offset isn't high enough for use on the front? Anyone know for sure? TIA

[mfanatic325]

Originally Posted by Incompatible

Sorry guys, a slightly OT question. While looking at various wheel manufacturers, occassionally I'll see the restriction "rear use only". I'm guessing that the load rating for that specific width/offset isn't high enough for use on the front? Anyone know for sure? TIA

It's usually because of the wheel width and/or the offset that causes it to be front OR rear use only.

[mfanatic325]

Originally Posted by SSKE92

Would these Style 5's fit Z4M?
http://forum.e46fanatics.com/showthread.php?t=821890

The front offset is a bit too aggressive I think. But with those included tire sizes, you might be okay. Then again, 225's are a bit thin for Z4M fronts.
The rears should clear no problem.

[onebluemcm]

EDIT - I'm full of s#it.

Originally Posted by sho-one

19"x9.0" +31mm Front
19"x10.0" +25mm Rear

M3 Comp Wheels, I keep getting different answers, Please help. Will this fit a z4 M coupe without rubbing? 245F 275 rear tires.

Thanks all =)

A 9" +31 is going to give very little clearance (less than 3 mm as an educated guess) to the strut, if it doesn't rub outright. Mine, granted with a 18" 255/40, have I'd say 5-6 mm clearance, tire to strut. Will be close, possibly a gamble.

EDIT - I'm full of s#it. The above statement is wrong, wrong, wrong. Don't know what I was thinking. 9" et31 would give more clearance to the strut than my 9" et38. My guess is that et31 on a 9" wheel will have too much rub on the fender or fender liner. Man, I'm an idiot

[BTM]

Originally Posted by mfanatic325

The front offset is a bit too aggressive I think. But with those included tire sizes, you might be okay. Then again, 225's are a bit thin for Z4M fronts.
The rears should clear no problem.

Am I mistaken in saying that it is possible to grind down the hubs and increase offset? That might be an option as well. I've definitely seen style 5's on a Z4 before

Not my style, but found the picture:

[mfanatic325]

You mean the inside center portion of the wheel? Yeah, I've heard that it's do-able for most wheel materials. However, I've never really felt all that inclined to alter an already-made wheel. I suppose working on a forged wheel might be okay, but still..the thought of "harming" the wheel is kind of a turn-off

[mfanatic325]

Originally Posted by onebluemcm

A 9" +31 is going to give very little clearance (less than 3 mm as an educated guess) to the strut, if it doesn't rub outright. Mine, granted with a 18" 255/40, have I'd say 5-6 mm clearance, tire to strut. Will be close, possibly a gamble.

It depends on the offset. I've seen a Z4MC lowered on coilovers and running 9" width wheels up front, with +35 offset.
Hence why I was thinking about using the rear wheels from my non-M fitment set of LE37's (which were also 9" width, but with +43 offset), and put them up front on the MC.
But someone already paid for the LE's

[onebluemcm]

Originally Posted by BTM

Am I mistaken in saying that it is possible to grind down the hubs and increase offset? That might be an option as well. I've definitely seen style 5's on a Z4 before

Not my style, but found the picture:

It may be possible to remove material from the mating surface of the wheel, yes. May is the critical word. If there is not enough material left, there is a very, very real risk of a catastrophic failure; i.e., wheel flange pulling off of the wheel, wheel rolls down road unatached to car, car meets telephone pole/rock/barrier/other vehicle, you die. You'd want to speak directly with an engineer of the wheels in question about this.

More importantly, going at any wheel flange with a grinder would be like trying to restore a fine piece of art with a belt sander, or something. Do not do this!! The wheel flange, that mates up to the hub/rotor has to be as near perfectly parallel with the rim as possible. When it's out of parallel, it's called runout, this is a bad thing. All wheels will have some runout but on the best wheels it's miniscule. Aside from a CNC shop with an engineer or highly experienced operator, there is basically no practical way to remove material from the flange in any precise way. I think it would be hard to find a CNC shop that would be willing to do this simply for liability reasons.

[Incompatible]

Originally Posted by onebluemcm

It may be possible to remove material from the mating surface of the wheel, yes. May is the critical word. If there is not enough material left, there is a very, very real risk of a catastrophic failure; i.e., wheel flange pulling off of the wheel, wheel rolls down road unatached to car, car meets telephone pole/rock/barrier/other vehicle, you die. You'd want to speak directly with an engineer of the wheels in question about this.

More importantly, going at any wheel flange with a grinder would be like trying to restore a fine piece of art with a belt sander, or something. Do not do this!! The wheel flange, that mates up to the hub/rotor has to be as near perfectly parallel with the rim as possible. When it's out of parallel, it's called runout, this is a bad thing. All wheels will have some runout but on the best wheels it's miniscule. Aside from a CNC shop with an engineer or highly experienced operator, there is basically no practical way to remove material from the flange in any precise way. I think it would be hard to find a CNC shop that would be willing to do this simply for liability reasons.

X100 Well said! To OP: Be patient, educate yourself on what specs work, and buy a wheel that meets your needs, one that was made for the car. In the long run you'll save money, headaches, and be safer.

[r4gs]

F: 18x8.5 et35 with 245/40
R: 18x9.5 et35 with 265/40

will the rears clear the inside of the rear wheel wells? calculators are showing 11mm less wheel to strut clearance.