Fitting 18x10.5+22 squared on E46 M3

[BBRTuning]

Yeah, that's my car (it doesn't rub). 18x10.5 +25 and 275/35-18 RE71RS. Some of the tracks here, particularly Buttonwillow, are quite gnarly and would quickly destroy fenders if there was *any* chance of rubbing of the tire under compression/steering input. Numerous chances for 2 / 3 wheels in the air off the curbs.

To each his own - I still regularly suggest 18x10 +25 with a 265/35 to most E46M3 track guys. I personally wanted to run a 275, for various reasons, so I worked backwards. 10.5" to me is the required wheel width for proper sidewall stability and feel for most of the 275 width track tires these days, so I found the highest offset I could fit with front inner clearance, set camber based on tire wear and my tire pyrometer, and did what I had to do to the fenders, front and back, to properly fit the setup.

The one disadvantage of running aggressive front fitments is just the aero drag of the tire's leading edge. This can be mostly fixed with front aero & endplates. Further down the road I have plans for wider front bodywork to fit it better aerodynamically and still run a "non-aero" setup but that's a ways off.

[Tbonem3]

I be';ieve Beau, but also know that there are lots of variables, especially tire width. Yoko a052 in 265 is 9.9" wide! Where as the still :"fat" ps4s in 275 is 9.8" wide.

It's certainly questionable that a 10.5" wheel would fit up front when the stock rears are only 9" lol but with the right conditions, one can just make it work.

Luckily, it works out because those wanting to fit a 10.5" probably have cars where they are willing to pull/shave/roll fenders i.e., track cars, Non track car wouldn't want 10.5" anyway save the stance krew kids on IG. Well kept street m3s need not apply imo.

[MTiz]

So what's the final verdict? Will he need camber plates and fenders rolled, or can it be made to fit? I ask because I picked up a cheap set of Apex's from a friend with those same specs with 275s on them, and I'm wondering if I can run them or if I should flip them. I would rather not roll my fenders if it can be avoided, but I do have height adjustable KW's and I'd be open to getting camber plates.

[bmw m3 s50]

Yeah, that's my car (it doesn't rub). 18x10.5 +25 and 275/35-18 RE71RS. Some of the tracks here, particularly Buttonwillow, are quite gnarly and would quickly destroy fenders if there was *any* chance of rubbing of the tire under compression/steering input. Numerous chances for 2 / 3 wheels in the air off the curbs.

To each his own - I still regularly suggest 18x10 +25 with a 265/35 to most E46M3 track guys. I personally wanted to run a 275, for various reasons, so I worked backwards. 10.5" to me is the required wheel width for proper sidewall stability and feel for most of the 275 width track tires these days, so I found the highest offset I could fit with front inner clearance, set camber based on tire wear and my tire pyrometer, and did what I had to do to the fenders, front and back, to properly fit the setup.

The one disadvantage of running aggressive front fitments is just the aero drag of the tire's leading edge. This can be mostly fixed with front aero & endplates. Further down the road I have plans for wider front bodywork to fit it better aerodynamically and still run a "non-aero" setup but that's a ways off.

This is an issue that I always thought about as well. I also tend to run wide tires up front. The downside of running wide tires up front with the OEM e46 m3 fender flare is the design. As you mentioned, the outside tire edge remains exposed creating drag. Its one thing I wish BMW designed better, along more pronounced rear flares. I guess BMW engineers only excepted these car to run the 225/255 or 235/265 tire sizing.

[Gearhead55]

So what's the final verdict? Will he need camber plates and fenders rolled, or can it be made to fit? I ask because I picked up a cheap set of Apex's from a friend with those same specs with 275s on them, and I'm wondering if I can run them or if I should flip them. I would rather not roll my fenders if it can be avoided, but I do have height adjustable KW's and I'd be open to getting camber plates.

You will need to roll your fenders to fit this wheel/tire size, along with running -3.5* or more negative camber up front.

[Nate047]

So what's the final verdict? Will he need camber plates and fenders rolled, or can it be made to fit? I ask because I picked up a cheap set of Apex's from a friend with those same specs with 275s on them, and I'm wondering if I can run them or if I should flip them. I would rather not roll my fenders if it can be avoided, but I do have height adjustable KW's and I'd be open to getting camber plates.

You should get camber plates regardless imo.

[bigjae46]

Yeah, that's my car (it doesn't rub). 18x10.5 +25 and 275/35-18 RE71RS. Some of the tracks here, particularly Buttonwillow, are quite gnarly and would quickly destroy fenders if there was *any* chance of rubbing of the tire under compression/steering input. Numerous chances for 2 / 3 wheels in the air off the curbs.

To each his own - I still regularly suggest 18x10 +25 with a 265/35 to most E46M3 track guys. I personally wanted to run a 275, for various reasons, so I worked backwards. 10.5" to me is the required wheel width for proper sidewall stability and feel for most of the 275 width track tires these days, so I found the highest offset I could fit with front inner clearance, set camber based on tire wear and my tire pyrometer, and did what I had to do to the fenders, front and back, to properly fit the setup.

The one disadvantage of running aggressive front fitments is just the aero drag of the tire's leading edge. This can be mostly fixed with front aero & endplates. Further down the road I have plans for wider front bodywork to fit it better aerodynamically and still run a "non-aero" setup but that's a ways off.

How close are the rears? I'm thinking about fitting 295/30R18 Toyo RRs on a 10.5,et22 wheel. I think the RRs don't run very wide.

[Obioban]

Personally, I would not want my alignment determined by my need to make things “fit”

... and generally I think people run way more camber than is beneficial, as a result of being too low and in a shitty place on the camber curve as a result (need to compensate for lack of dynamic camber with excess static camber).

Street and track.

[BBRTuning]

How close are the rears? I'm thinking about fitting 295/30R18 Toyo RRs on a 10.5,et22 wheel. I think the RRs don't run very wide.

Definitely will need to shave the inner fender and possibly flare the fender some. Mine are widened maybe 12mm over factory all around. The shorter diameter of the 295/30 might help slightly though. Might be able to run a higher offset too but unfortunately that's harder to find.

Personally, I would not want my alignment determined by my need to make things “fit”

... and generally I think people run way more camber than is beneficial, as a result of being too low and in a shitty place on the camber curve as a result (need to compensate for lack of dynamic camber with excess static camber).

Street and track.

I have roll centre and geometry correction in front and rear (entire trailing arm is offset) putting everything close to factory angles at the lower height, with the exception of the rear lower arm pickup point which has been flipped to keep both rear arms more parallel than factory. It did allow me to run slightly less static camber and slightly less spring rate all around than without it due to the roll centre change and improved anti-squat. 3.8-4* front and 2.8* rear results in relatively even tire temps and tire wear, actually could use a touch more rear camber but I compromise slightly to aid in traction exiting slower corners. I don't really know of any fast E36/E46 track cars that don't run at least 4* front camber, certainly the whole B1/B2 Bimmer Challenge field and the SCCA GT2 cars I do calibration on. We'd all love to run less if possible. You of course sacrifice some braking performance, but with the relatively low power level (and therefore speeds entering braking zones) of these cars NA, the benefits in avg cornering speed outweigh the loss in braking performance on most tracks here. On a higher HP car or a track with long straights and critical braking zones this would likely be different.

Don't think I've ever used alignment to "fit" a wheel/tire. For me the process is pick the tire you want to run, match the wheel to that tire, set the geometry and alignment based on testing and data, and do what you need to fenders etc to make that fit. Pretty simple.

Sure there are some compromises to scrub radius and to aero due to the leading edge of the tire, but these are both not trivial to resolve. I decided for me the benefits of the wider tire and its increased thermal mass outweigh the disadvantages. If someone comes out with a custom knuckle with better strut clearance to allow a higher offset wheel I'd probably do it. A friend of mine is fitting E9x-based front suspension to his E46 to allow an 11" higher offset wheel to fit the front but it's turning into a pretty crazy one-off project.

[cornerbalanced]

Personally, I would not want my alignment determined by my need to make things “fit”

... and generally I think people run way more camber than is beneficial, as a result of being too low and in a shitty place on the camber curve as a result (need to compensate for lack of dynamic camber with excess static camber).

Street and track.

Curious about this notion of running “way more camber than is beneficial”. I’ve found these cars, more so most cars with McPherson struts respond particularly well to increased negative camber. Always eager to learn more nonetheless.

For certain tires like NT01s, and r-comps, you’re doing a great disservice to the tire running anything less than -3deg…in some cases even that isn’t enough.

[cornerbalanced]

For fun —

Here’s my car on 18x10.5+22 sq. BBS RIAs, 275/35r18 Kumho V730s sq.

-3.0* camber front / -2.2* camber rear

They ‘fit’, didn’t experience rubbing lock to lock somehow. As others have mentioned, -3.5* of front camber would really be the sweet spot to get these to fit “well”. My fenders are slightly rolled, but not shaved.

Ultimately decided on going 18x10+25 / 265/35r18 sq. I really believe this to be the optimal setup for E46s that see track/canyon time. Past a 265 width tire I’ve found steering feel begins to drop off…many moons ago I ran 285/30 sq. Never again.

[bigjae46]

Definitely will need to shave the inner fender and possibly flare the fender some. Mine are widened maybe 12mm over factory all around. The shorter diameter of the 295/30 might help slightly though. Might be able to run a higher offset too but unfortunately that's harder to find.

Think it would work if I could get the seam sealer out and then get the rear fender lip flat? I know its gonna be difficult. I'm not worried about the paint cracking, gonna repaint it anyway.

[bigjae46]

Curious about this notion of running “way more camber than is beneficial”. I’ve found these cars, more so most cars with McPherson struts respond particularly well to increased negative camber. Always eager to learn more nonetheless.

For certain tires like NT01s, and r-comps, you’re doing a great disservice to the tire running anything less than -3deg…in some cases even that isn’t enough.

I run -4.0 in the front and -3.0 in the rear on NT01s. Its more of a compromise for me because of my relatively low spring rates. I really need to rebuild my rear TCKs to handle more spring rate.

[Wernd]

275 RE71Rs work great on a 10" wide rim there's no need to screw around with a 10.5" wide rim. Would there be associated benefits with the 10.5" rim, yes, would it be substantial, no. Would it be worth the effort of fitting a 10.5", that's up to the installer. But to act like a 275 isn't optimal on a 10" rim is ludicrous

[bigjae46]

Would an ET34 or ET40 wheel work better?