[M1500Z]

I've been on a quest, so to speak, to find a wheel that ticks a few boxes. The further I go down this path, the more lost I get. It's been difficult scouring forums and googling in order to do something other than the easy button.

Here's what I think I want

• A square setup for 275/35 r18
• Clears my Öhlins R&T
• Is lightweight
• Looks aesthetically pleasing (subjective)
• Cost is around or less than $2500

The frustration is that everything seems to be either a problem with the front or the rear unless It's ~18x10 +30ish. And that's where it becomes problematic for me because the options in that size that are cost effective, lightweight, and aesthetically pleasing seem to be extremely limited.

In the 18x10 +30ish range, about the only wheel I can find that's respectable in weight is the Bimmerworld TA16, quoted at 19.5 lb. Subjectively, these aren't my favorite in appearance (get over it, wah wah wah). The fit out back is good and would just require a spacer up front.

If I get aggressive in the rear with, I can run Titan 7 T-S5s in 18x10 +25 (18.6 lb)for not much more cost and even more weight savings (nearly 1lb per corner), and I like the appearance.

That brings me to the Titan 7 T-S5 in an 18x10.5 +34 (18.9 lb). These are an easier fit in the rear, but could be a hassle in the front... BUT, I have seen this car is running 18x10.5 + 40 square with an 18mm spacer up front with 275/35 NT01s. So what gives? I think the stretch would aid responsiveness.

Apex makes wheels that look nice—I like both EC7 and SM10, but they are heavy compared to the above and every single lb dropped on this car is a battle won to me.

Lastly, there is an alternative for a staggered setup of 275F and 295 or 285R, but I don't even know what tires are available in this configuration.

*Phew* With all that said, what are your thoughts?
Is the ability to rotate that important?
Would having wider tires require more neg. camber or less?
Are 18x10.5" wheels a fool's errand?
Are there wheels I'm missing?
Am I overthinking this? (yes, it's what I do)

[Rundskop]

I've dealt with suspension and wheel fitment quite a bit on my 135i, and am now in a similar situation as you are, but with the M2C.

Some thoughts regarding your desired fitment:

Hip To Be Square:
I'd focus on the handling characteristics of a square set-up over the cost benefit. Meaning you might consider the same width but different offsets to hopefully give you more options.

Rear Sizing:
10.5" +34 seems to be the widest you can go with 275/35/18*. Camber would probably need to be -2 or greater and ride height is a factor.

Ohlins Fitment:
From my research on Ohlins RT, with their standard length front spring of 7.87" with a 9.5" front wheel and 265/35 tire, you would need about +22 to +25 offset.

So about the equivalent to a 10" +16 up to +20. This would provide the same inboard clearance to the strut, but it would have 12.4mm more poke. I would speculate that this is doable with the right camber likely > -2.0.

Helpful Bimmerpost links you may have already seen:
KW w/9.5 +23
HRE 9.5" front w/Ohlins
10'' 437 Rim on front w/Ohlins
OEM Wheels w/Ohlins
10" +34 rear fitment*

(Main thread link at top of each post linked above)

Other Factors:
Is there a difference between the Camber Plate used and its potential effect on the struts spring perch height? (Read: ride height, droop)

Is Ground Control, Vorshlag or Millway the same in that regard? I'm not sure, but it may be negligible... Maybe this only matters if you want to run a substantially shorter spring??

Spring preload: you might be in a position where you could increase the preload from the recommended, lets say 5mm or 10mm, to 20mm which would raise the spring perch, providing more tire clearance and be totally fine. I see minimal to zero downside if that's all it would take.

M2 vs M2C - fender liner clearance is better on the 'standard' M2 I believe, so that's a plus.

How short of a front spring can you go with the Ohlins? I know there are 5" and 6" and then you could use a helper spring but I don't know if there's any downside or what limitations there are the shorter you go.

All of this is from my research only, as I'm waiting on my Ohlins to arrive with a 7" front spring, to be paired with 9.5" +26 front wheels.

I hope this helps. I'm sure others will chime in with more first hand experience than I have.

[M1500Z]

Originally Posted by Rundskop

Hip To Be Square:
I'd focus on the handling characteristics of a square set-up over the cost benefit. Meaning you might consider the same width but different offsets to hopefully give you more options.

That is one possibility, and one I've been thinking about as it may be a very viable solution although it takes away a big positive in the ability to rotate at the track.

Originally Posted by Rundskop

Rear Sizing:
10.5" +34 seems to be the widest you can go with 275/35/18*. Camber would probably need to be -2 or greater and ride height is a factor.

Currently, I am at -2.3 in the rear with maybe 5-8mm of room to play. This is with the stock rear wheel + 10mm spacer (effective +30) and a Goodyear SC3 265/35 r19.

Originally Posted by Rundskop

Ohlins Fitment:
From my research on Ohlins RT, with their standard length front spring of 7.87" with a 9.5" front wheel and 265/35 tire, you would need about +22 to +25 offset.

So about the equivalent to a 10" +16 up to +20. This would provide the same inboard clearance to the strut, but it would have 12.4mm more poke. I would speculate that this is doable with the right camber likely > -2.0.

This is where things become difficult. Here is what I currently have:

Stock front wheel + 12mm spacer (effective +17)
-3.2° camber
Goodyear SC3 245/35 r19

I haven't been able to accurately measure the distance from the tire to perch, but inside it appears to be around 18mm tire<->perch and the wheel has a lot more clearance as the lip is underneath the perch. Without the spacer I'd only have roughly 6mm of clearance. The outside has plenty of room and I think even -3.5° camber would be fine (especially with a 275 up front—more mechanical grip should mean more aggressive camber I would think).

Looking at the difference between 10 +13 (+25 with my 12mm spacer) and 10.5 +14 (+34 with 20mm spacer) the difference is somewhat negligible in terms of tire clearance. I need to find a calculator that lets me compare 3 wheels at a time—I've been using this one.

Originally Posted by Rundskop

Other Factors:
Is there a difference between the Camber Plate used and its potential effect on the struts spring perch height? (Read: ride height, droop)

Is Ground Control, Vorshlag or Millway the same in that regard? I'm not sure, but it may be negligible... Maybe this only matters if you want to run a substantially shorter spring??

Spring preload: you might be in a position where you could increase the preload from the recommended, lets say 5mm or 10mm, to 20mm which would raise the spring perch, providing more tire clearance and be totally fine. I see minimal to zero downside if that's all it would take.

M2 vs M2C - fender liner clearance is better on the 'standard' M2 I believe, so that's a plus.

How short of a front spring can you go with the Ohlins? I know there are 5" and 6" and then you could use a helper spring but I don't know if there's any downside or what limitations there are the shorter you go.

All of this is from my research only, as I'm waiting on my Ohlins to arrive with a 7" front spring, to be paired with 9.5" +26 front wheels.

I hope this helps. I'm sure others will chime in with more first hand experience than I have.

I'm hoping you're right in that others will chime in... maybe with alternate wheel choices too 🤞🏼. I'm tired of banging my head against the wall. Also, I have an M2 Comp (despite my photo).

[mr_lab_rat]

What is the main reason for 18? 19 would give you ton of options with my favourite being 437m square.

[Rundskop]

Is there any difference with the front hub and/or shock between M2 vs M2 Comp?

Let's say both cars have same suspension and wheel offset:

- 19x9.5 +22 front

Would the clearance of the wheel/tire to the strut be the same for both?

There are some that claim 9.5 +27 clears Ohlins. Not sure if that implies standard Ohlins spring length, Ohlins recommended preload. Or if they're just increasing preload to clear the tire, or if it works on a M2C but not on M2?

If we know a 10" +20 front works, then the equivalent for outboard clearance in 9.5" wheel is 9.5" +13, but it would give you 13mm MORE clearance away from strut.

For those that have camber plates I'm surprised we have not see more low offset 9.5" front wheels. It appears anything from 9.5" +13 through 9.5" +22 would work fine w/Ohlins.

[M1500Z]

Originally Posted by Rundskop

Is there any difference with the front hub and/or shock between M2 vs M2 Comp?

There is no difference between front hub and strut on the two cars that I am aware of.

Originally Posted by Rundskop

Let's say both cars have same suspension and wheel offset:

- 19x9.5 +22 front

Would the clearance of the wheel/tire to the strut be the same for both?

Yes. The stock wheel (19x9 +29) clears Öhlins on both cars.

Originally Posted by Rundskop

There are some that claim 9.5 +27 clears Ohlins. Not sure if that implies standard Ohlins spring length, Ohlins recommended preload. Or if they're just increasing preload to clear the tire, or if it works on a M2C but not on M2?

If we know a 10" +20 front works, then the equivalent for outboard clearance in 9.5" wheel is 9.5" +13, but it would give you 13mm MORE clearance away from strut.

For those that have camber plates I'm surprised we have not see more low offset 9.5" front wheels. It appears anything from 9.5" +13 through 9.5" +22 would work fine w/Ohlins.

There is actually a good amount of wheel clearance to the strut, but the tire is a different story. Low offsets look like they would be just fine—for instance I just swapped to a bigger spacer up front and am currently am running an effective 19x9 +11 (18mm spacer) and am easily clearing the fender with -3.2° front camber.

With all of that said, I caved. I spent more than I'd hoped to and the wheels aren't a rotatable square setup. There is a positive to this and that is I will have both 18x10 +25 and 18x10.5 +37 wheels—I'll be able to test the 10.5 up front and the 18x10 in the rear.

I do think that the BW TA16 wheels are the sweet spot and if they are aesthetically pleasing, a fantastic choice.

[Rundskop]

Originally Posted by M1500Z

There is no difference between front hub and strut on the two cars that I am aware of.

Yes. The stock wheel (19x9 +29) clears Öhlins on both cars.

There is actually a good amount of wheel clearance to the strut, but the tire is a different story. Low offsets look like they would be just fine—for instance I just swapped to a bigger spacer up front and am currently am running an effective 19x9 +11 (18mm spacer) and am easily clearing the fender with -3.2° front camber.

With all of that said, I caved. I spent more than I'd hoped to and the wheels aren't a rotatable square setup. There is a positive to this and that is I will have both 18x10 +25 and 18x10.5 +37 wheels—I'll be able to test the 10.5 up front and the 18x10 in the rear.

I do think that the BW TA16 wheels are the sweet spot and if they are aesthetically pleasing, a fantastic choice.

Well I'll be interested to hear what you find out with both wheel options available for testing.

[Wisco M3]

Originally Posted by Rundskop

Well I'll be interested to hear what you find out with both wheel options available for testing.

Ditto. Looking at the clearance on my car with 18x10, I can't believe an 18x10.5 isn't an easy fit. I'm just not willing to spend the coin to get there at this point. I'd ideally like an 18x10.5 square setup, even if I have to use spacers somewhere.

I run 275's without issue, and have a set of 285's to mount up. My hope is 295.

[Rundskop]

Any update? Curious to hear how the test fitting went.

[M1500Z]

Originally Posted by Rundskop

Any update? Curious to hear how the test fitting went.

My wheels arrived about 2 weeks ago. I had to order some clamp-in valve stems but my package was lost and a new one was shipped. Hopefully I'll have an update by week's end.

[GreenLightGo]

I own a 2020 M2C that I use mostly for track use, and occasional street driving. I have added Ground Control camber plates, Dinan coil-overs and sway bars, Dinan heat exchanger and HE+ engine tune. I run the stock wheels and tires in the street. For the track, I have 19" OZ Hyper GT wheels with Michelin Cup 2 tires in the stock tire size (245/35 front, 265/35 rear). I am finding that the tires aren't enough for the added hp and torque. I'm looking to stuff bigger rubber on both the front and rear. Apex has a recommended fitment with a 265/30-19 front and 295/30-19 rear. However, the Cup 2 doesn't come in a 265/30 size. I have spoken to Dinan, my BMW tuning shop, and my local tire shop. The general opinion seems to be that the 295/35 will likely rub under compression. There is no concern from Dinan about the coil-overs, as the springs aren't bigger than stock, just a different compression, so they won't take up more room in the wheel well. The issue will be the fender and liner clearance with the larger diameter tire in a lowered suspension.

Has anyone tried to stuff at 295/35-19 into the rear of an M2?

What are your thoughts about running a 295/30 in the rear, and a 265/35 in the front? Here are the diameters of the Cup 2's, according to Michelin:

295/35-19: 27.12
295/30-19: 26.02
275/35-19: 26.62
265/35-19: 26.32 (Stock)
265/30-19: DON’T MAKE IT
255/35-19: 26.02
245/35-19: 25.82 (Stock)

Other tires mfg in a 265/30 and 295/30: Pirelli P Zero Troffeo R and Toyo Proxes R888R. Let me know if anyone has track experience with those tires.

Thanks!!

[M1500Z]

Half-ass update

I was a little pressed for time and didn't get to do any real test fitting. I'll get around to it maybe this weekend weather and shop dependent. I had planned to be a bit more methodical about this, but doing write-ups on the internet isn't really my thing.

So for the time being, here's what I've got. My notes are just a collection of thoughts at this time. Thus far, I'm pretty happy, but slightly peeved at having to order spacers again.


Front 18x10" +15 (+25 with 10mm spacer) & 275/35 R18 Goodyear SC3

Notes
-3.2 camber and not exceptionally low. I'd like to lower the car more for aesthetics but it's not doable if I want to be drive out of my alley. The fender clearance is aggressive but I have no rubbing on the road but have not been on track. The strut has room to run a thinner spacer so I'll likely try a 5mm and no spacer to see. The 18x10.5" +37 would be tough to fit and would likely require an 18-20mm spacer minimum. I'd prob avoid this without adjustable arms to bring the whole assembly inboard, otherwise you'll likely end up with your wheel and or tire size dictating your alignment. You could run a 10.5" wheel up front with a smaller tire, but that's not why we're here.








Rear 18x10.5" +35 & 275/35 R18 Goodyear SC3

Notes
-2.3 camber and fitment is nearly identical to before. Ton of inboard clearance and I've still got the ability to remove camber if I see fit. Seems nearly perfect without a spacer, but have the option of running one for aesthetics.

[Wisco M3]

I’m sitting a shade higher than you and had to go w/ a 12.5mm spacer and 285 wide tires in front. The 7.5 was too close to the strut for my comfort.

One thought - anyone going with shorter overall springs in front to gain more tire clearance? Potential issues with spring bind?

[VisualEcho]

Originally Posted by GreenLightGo

I own a 2020 M2C that I use mostly for track use, and occasional street driving. I have added Ground Control camber plates, Dinan coil-overs and sway bars, Dinan heat exchanger and HE+ engine tune. I run the stock wheels and tires in the street. For the track, I have 19" OZ Hyper GT wheels with Michelin Cup 2 tires in the stock tire size (245/35 front, 265/35 rear). I am finding that the tires aren't enough for the added hp and torque. I'm looking to stuff bigger rubber on both the front and rear. Apex has a recommended fitment with a 265/30-19 front and 295/30-19 rear. However, the Cup 2 doesn't come in a 265/30 size. I have spoken to Dinan, my BMW tuning shop, and my local tire shop. The general opinion seems to be that the 295/35 will likely rub under compression. There is no concern from Dinan about the coil-overs, as the springs aren't bigger than stock, just a different compression, so they won't take up more room in the wheel well. The issue will be the fender and liner clearance with the larger diameter tire in a lowered suspension.

Has anyone tried to stuff at 295/35-19 into the rear of an M2?

What are your thoughts about running a 295/30 in the rear, and a 265/35 in the front? Here are the diameters of the Cup 2's, according to Michelin:

295/35-19: 27.12
295/30-19: 26.02
275/35-19: 26.62
265/35-19: 26.32 (Stock)
265/30-19: DON’T MAKE IT
255/35-19: 26.02
245/35-19: 25.82 (Stock)

Other tires mfg in a 265/30 and 295/30: Pirelli P Zero Troffeo R and Toyo Proxes R888R. Let me know if anyone has track experience with those tires.

Thanks!!

I too am a huge fan of the 265/30 & 285/30 combo...but not so much of the Cup2.

I ADORE the Trofeo R!!! What a pussycat of a tire! So fantastic! I also like the PZero Corsa, but it's pretty terrible after about 5,000 miles. The 888R is a JUNK Internet-Sensation tire.

Trofeo R FTW, and never look back!

[Rundskop]

Originally Posted by M1500Z

Half-ass update
So for the time being, here's what I've got. My notes are just a collection of thoughts at this time. Thus far, I'm pretty happy, but slightly peeved at having to order spacers again.


Front 18x10" +15 (+25 with 10mm spacer) & 275/35 R18 Goodyear SC3

Notes
-3.2 camber and not exceptionally low. I'd like to lower the car more for aesthetics but it's not doable if I want to be drive out of my alley. The fender clearance is aggressive but I have no rubbing on the road but have not been on track. The strut has room to run a thinner spacer so I'll likely try a 5mm and no spacer to see. The 18x10.5" +37 would be tough to fit and would likely require an 18-20mm spacer minimum. I'd prob avoid this without adjustable arms to bring the whole assembly inboard, otherwise you'll likely end up with your wheel and or tire size dictating your alignment. You could run a 10.5" wheel up front with a smaller tire, but that's not why we're here.

Awesome stuff man! This is super helpful.

I ended up getting Ohlins on and am running a 7" front spring, instead of the standard 7.87" Ohlins provided.

Here's a couple pics of it on stock tire and wheels. Looks like if I really needed the extra room I could increase preload 5-8mm.

Ride height is 5-10mm lower in front. I measured ~26.5" front fender to floor.

Based on your info and others with square set up the 10" et15-20 makes sense for the front. Especially considering you're on 275/35/18.

Edit: wanted to add this image for reference, which shows a 4mm tool that displays there's approximately ~10mm of clearance between the 9" et29 788M and 245/35 set up to spring perch.

[M1500Z]

Originally Posted by Wisco M3

I’m sitting a shade higher than you and had to go w/ a 12.5mm spacer and 285 wide tires in front. The 7.5 was too close to the strut for my comfort.

One thought - anyone going with shorter overall springs in front to gain more tire clearance? Potential issues with spring bind?

What is your wheel size/offset (without spacer) with the 285 up front? I'd like to try a shorter spring, but at this point I may begin to consider moving toward a 2-way setup that runs a smaller diameter spring.

Originally Posted by Rundskop

Awesome stuff man! This is super helpful.

I ended up getting Ohlins on and am running a 7" front spring, instead of the standard 7.87" Ohlins provided.

Here's a couple pics of it on stock tire and wheels. Looks like if I really needed the extra room I could increase preload 5-8mm.

Ride height is 5-10mm lower in front. I measured ~26.5" front fender to floor.

Based on your info and others with square set up the 10" et15-20 makes sense for the front. Especially considering you're on 275/35/18.

Edit: wanted to add this image for reference, which shows a 4mm tool that displays there's approximately ~10mm of clearance between the 9" et29 788M and 245/35 set up to spring perch.

What is the ID of the Öhlins spring? That seems to be a big factor in clearance for these struts. I measured my ride height btw and am at 25.75" fender to floor up front. The tire stretch makes a significant difference in clearance as that's right where the collars are.

Another small update
In the name of science, I went and test fit the 18x10.5 +37 on the front of the car. With a 10mm spacer (+27) it is far from clearing, with an 18mm (+19) the tire will spin however you'd never track the car with this wheel and a 275 tire. I'd be afraid to drive it much honestly. You'd need a 25mm spacer or larger to fit and an excessive amount of camber unless mimicking the CS Racing setup with adjustable arms and bringing the entire assembly further in-bound.

For the rear, I would just avoid a 10 +25 unless you are ok running -2.5° or more in the rear.

[Rundskop]

Originally Posted by M1500Z

What is your wheel size/offset (without spacer) with the 285 up front? I'd like to try a shorter spring, but at this point I may begin to consider moving toward a 2-way setup that runs a smaller diameter spring.

What is the ID of the Öhlins spring? That seems to be a big factor in clearance for these struts. I measured my ride height btw and am at 25.75" fender to floor up front. The tire stretch makes a significant difference in clearance as that's right where the collars are.

Someone is selling a set of used JRZ RS2 right now in the M2 classifieds.

Ohlins springs are 65mm ID.

Even with the 8-10mm clearance, from utilizing the shorter spring, I still think it's good I opted for the 9.5" +13 spec wheel. I'd like to run a 265/30 and maybe have the option for 275/30.

Originally Posted by M1500Z

In the name of science, I went and test fit the 18x10.5 +37 on the front of the car. With a 10mm spacer (+27) it is far from clearing, with an 18mm (+19) the tire will spin however you'd never track the car with this wheel and a 275 tire. I'd be afraid to drive it much honestly.

You might need to go with a 60mm ID spring option, with MCS or Nitron and then even still use a 6'' or shorter spring.

[GreenLightGo]

Originally Posted by VisualEcho

I too am a huge fan of the 265/30 & 285/30 combo...but not so much of the Cup2.

I ADORE the Trofeo R!!! What a pussycat of a tire! So fantastic! I also like the PZero Corsa, but it's pretty terrible after about 5,000 miles. The 888R is a JUNK Internet-Sensation tire.

Trofeo R FTW, and never look back!

I just got back from two days at Watkins Glen, and here is an update on my track setup:

I put on fresh Cup2's in sizes 265/30-19 front, and 295/30-19 rear. No problems with rubbing, even under compression when hitting the bus stop curbing at 90 mph. This tire setup is ideal, imo. With the engine tune and suspension upgrades, the stock tire sizes were just not up to the task. You had to be careful rolling on to the throttle out of corners, or you would slide the rear. The wider rubber is a perfect complement to the increased HP and torque. The car tracked well into corners, with no understeer, and the rear end stuck like glue when you got on the throttle at the apex. It was an amazing difference. I am sold on this setup. I might try the Troffeos, but I have no issues with the Cup2's, so I'm not looking to make a change in that dept right now.

Now the bad news--my rotors warped after my third session on day 2. These are original stock rotors, with endless MX-72 pads. They have 11 track days on them, and 8,700 total miles. I don't know if warping is partially due to the wear on the rotors, or if the stock rotor just got too hot on my last session. The increased power, more aggressive rubber and stronger brake pads could be combining to push the stock rotors beyond their design limits. It seems like my options are to put new stock rotors on and see how long they last, or go with an aftermarket rotor designed for track use. Another option is finding a way to redirect the cooling air from the inlet in the wheel well so that it blows directly on the brakes.

I would love any feedback you have on a good rotor/brake solution. Thanks!

[bentom2]

GreenLightGo - Rotor “warping” is usually the pads getting too hot and leaving deposits on your rotors. I’m not familiar with the Endless pad lineup, but it looks like these are more of a dual purpose pad. Sounds like you’ve pushed beyond their heat limits and smeared some pad on the rotors.

Not sure what other pads are available for the 6 piston Comp brakes, but I’ve had good luck with Pagid RSL29, RSL1, performance Friction PFC08, and Ferodo 3.12. These are all true track pads that can handle higher temps than a dual purpose pad. I’ve found Zeckhausen Racing quite helpful in advising on brakes pads from a wide variety of sources in the past.

https://www.zeckhausen.com/

There are also lots of brake pad threads here on the forum that might already have the recommendations you’re looking for, or might be a better place to ask.

[VisualEcho]

Originally Posted by GreenLightGo

I put on fresh Cup2's in sizes 265/30-19 front, and 295/30-19 rear.

SHOW ME!!!

Originally Posted by GreenLightGo

Now the bad news--my rotors warped after my third session on day 2.

I second the fact that the rotors aren't warped, but merely have pad deposits. If you have a shop nearby that will turn them just slightly without removing much material, you can usually get it done for $12 a rotor, which is what I do. And yes, even if they have holes they can be turned.

[Dr.Mark]

Originally Posted by VisualEcho

SHOW ME!!!

I second the fact that the rotors aren't warped, but merely have pad deposits. If you have a shop nearby that will turn them just slightly without removing much material, you can usually get it done for $12 a rotor, which is what I do. And yes, even if they have holes they can be turned.

Or just put on a full track pad set and drive them on the streets for 1-2 weeks. They'll wear off the deposits.

[Wisco M3]

Originally Posted by M1500Z

What is your wheel size/offset (without spacer) with the 285 up front? I'd like to try a shorter spring, but at this point I may begin to consider moving toward a 2-way setup that runs a smaller diameter spring.

Apex EC-7 18x10 ET33. I ended up lowering the front of my car by another 1/4" for understeer issues (solved the problem) and that pushed the adjuster into the tire area, hence having to move the tire out a shade.

I'm on MCS 2 way remotes w/ 60mm ID springs, 6" w/ a helper spring and a spring rate of 500#.