[CSBM5]

Originally Posted by Dean_Clevername

Yep. I'm confined to B-Street rules so no mods. Not on a quest for ultimate camber, but in the past I've found toe alone can yield big changes to how a car drives. Was curious if any m2 b-street autocrossers have found value in straying from stock alignments with their setups and driving style.

The camber hubs might be legal (at least in the past factory offered parts were legal on other brands). BMW offers -0.5 and +0.5 degree options.

[CSBM5]

It looks like the A052 will be available soon in 255/35-19 and 275/35-19 for those forced to use 19" (M2C, M2CS). Those sizes now show up on Yokohama's US web site, so hopefully Tirerack will have them sometime in April.

[Dean_Clevername]

Originally Posted by CSBM5

The camber hubs might be legal (at least in the past factory offered parts were legal on other brands). BMW offers -0.5 and +0.5 degree options.

Are the camber correction hubs from BMW's line of performance parts (dealer/self installed) or an option you tick a box for when ordering and your M2 can leave the factory with them?

I don't recall ever seeing these as an orderable factory M2 option, which would be the only way (based on my understanding) they are legal for current B street rules

[CSBM5]

Originally Posted by Dean_Clevername

Are the camber correction hubs from BMW's line of performance parts (dealer/self installed) or an option you tick a box for when ordering and your M2 can leave the factory with them?

I don't recall ever seeing these as an orderable factory M2 option, which would be the only way (based on my understanding) they are legal for current B street rules

They are camber "correction" hubs, and I think they're legal, but someone would have to verify. I believe it falls under 13.8.E, "If offered by the manufacturer for a particular model and year, the use of shims, special bolts, removal of material to enlarge mounting holes, and similar methods are allowed and the resulting alignment settings are permitted even if outside the normal specification or range of specifications recommended by the manufacturer."

Since it's a factory approved means of adjustment specified in the factory repair manual and a factory supplied part, maybe it's legal? Similar items used to be from what I recall, but that's been ages now.

It's available in + and - 0.5 degrees values: https://www.realoem.com/bmw/enUS/sho...diagId=31_1121

[JustAWhisper]

So, I finally got my new wheels and tires mounted up and got my autocross alignment.

The 295 Yokos are wide. I haven't driven them on the street, but they probably will rub a bit under full compression as someone else mentioned. I'm OK with that as an autocross only set of tires. But, if Yoko ever offers a 285 I'll probably downgrade to that.

I wish I had read the latest posts on this thread before I got my alignment. My alignment guy and I expected to remove strut pins like in every BMW ever and get a nice additional 0.5 degrees of camber. Turns out BMW has decided that simple solution was too cheap and easy and engineered it out of the car.

On the rack my car shows only 1.0 degrees of camber. Yikes.

I ran across the camber correction hubs mentioned above after some internet searching, but they are not cheap. I was not expecting to have to spend another $800 bucks just to get a proper B-street autocross alignment. I expect it will be worth it in the long run, though, as the extra half degree will probably allow me to eek out a few more runs on each set of front tires. But, I'm not very happy right now.

[feconi]

I’m running 265/35/19 front and 285/35/19 rear RE-71s on my M2C since I had the rears left over from my C7. It rubs as expected on the front but tolerable for auto-x use. Will see how it does on stock alignment this weekend, will consider the correction hubs assuming BS legal.

Also worth pointing out I fitted the M3/4 Whiteline front sway (BBF44Z) on the car with no problems, it’s 3-way adjustable and costs quite a bit less than the Hotchkis or H&R options.

[AlpinewhiteM2C]

Originally Posted by JustAWhisper

So, I finally got my new wheels and tires mounted up and got my autocross alignment.

The 295 Yokos are wide. I haven't driven them on the street, but they probably will rub a bit under full compression as someone else mentioned. I'm OK with that as an autocross only set of tires. But, if Yoko ever offers a 285 I'll probably downgrade to that.

I wish I had read the latest posts on this thread before I got my alignment. My alignment guy and I expected to remove strut pins like in every BMW ever and get a nice additional 0.5 degrees of camber. Turns out BMW has decided that simple solution was too cheap and easy and engineered it out of the car.

On the rack my car shows only 1.0 degrees of camber. Yikes.

I ran across the camber correction hubs mentioned above after some internet searching, but they are not cheap. I was not expecting to have to spend another $800 bucks just to get a proper B-street autocross alignment. I expect it will be worth it in the long run, though, as the extra half degree will probably allow me to eek out a few more runs on each set of front tires. But, I'm not very happy right now.

OGM2 came out with 295 square Yokohama/ 18" Apex EC7 set up at last weeks test and tune event. He confirmed what you suspect: It will rub a bit up front under full compresssion, but nothing bad. Agree on cost of hubs being a prohibitive factor, especially if going coilovers with camber plates is in a future consideration.

[JustAWhisper]

After a couple days of driving on the street I'm already questioning my alignment. Since all we could adjust as toe we decided on going with BMW standard: 1/16" toe out in front, 1/8" toe in in rear.

Obviously the front likes to wander a lot of the highway, which is something I expected, but I'm really surprised to find that the car seems to push more than it did before, which does not fit with normal toe alignment logic. A little toe out should improve turn in.

Am I going crazy? Maybe there's something in the geometry that makes it like a bit of toe in? Or perhaps extra responsiveness is causing me to exceed the stock Michelin's (I daily drive on stock wheels and tires) grip faster.

I'm also noticing a slight decrease in the ability to put power down, so I'm thinking of push the rear toe in a bit more, basically back to where it was initially.

[Dean_Clevername]

Originally Posted by JustAWhisper

So, I finally got my new wheels and tires mounted up and got my autocross alignment.

The 295 Yokos are wide. I haven't driven them on the street, but they probably will rub a bit under full compression as someone else mentioned. I'm OK with that as an autocross only set of tires. But, if Yoko ever offers a 285 I'll probably downgrade to that.

I wish I had read the latest posts on this thread before I got my alignment. My alignment guy and I expected to remove strut pins like in every BMW ever and get a nice additional 0.5 degrees of camber. Turns out BMW has decided that simple solution was too cheap and easy and engineered it out of the car.

On the rack my car shows only 1.0 degrees of camber. Yikes.

I ran across the camber correction hubs mentioned above after some internet searching, but they are not cheap. I was not expecting to have to spend another $800 bucks just to get a proper B-street autocross alignment. I expect it will be worth it in the long run, though, as the extra half degree will probably allow me to eek out a few more runs on each set of front tires. But, I'm not very happy right now.

Dang, that's crazy. Brings me back to wondering what the actual factory spec is. If your car can't meet it (and I can't imagine just 1 deg is "in spec"), they should "correct the problem" with their correction hubs under warranty right right? I am only half kidding on that, but it begs the question. I was expecting to see 1.2deg or if I got really lucky maybe 1.4 whenever I get my car on a rack... time to adjust expectations

Finally had a chance to run with the 275 RT660 per above (with a mystery baseline alignment) and had no rubbing at all, no abs problems. Did have some understeer but it was too tight of a course for a fat car to draw too many conclusions from and I was overdriving just to get a feel for how it behaves when provoked. Still have the stock front sway installed too

[sholzer]

What is everyone doing for wheels for the M2C? M2 CS got classed in AS and I'll probably run my car a bit just for fun but would like to get another set of wheels. I didn't see anything from Apex that would fit the street class rules.

[JustAWhisper]

Originally Posted by Dean_Clevername

Dang, that's crazy. Brings me back to wondering what the actual factory spec is. If your car can't meet it (and I can't imagine just 1 deg is "in spec"), they should "correct the problem" with their correction hubs under warranty right right? I am only half kidding on that, but it begs the question. I was expecting to see 1.2deg or if I got really lucky maybe 1.4 whenever I get my car on a rack... time to adjust expectations

Finally had a chance to run with the 275 RT660 per above (with a mystery baseline alignment) and had no rubbing at all, no abs problems. Did have some understeer but it was too tight of a course for a fat car to draw too many conclusions from and I was overdriving just to get a feel for how it behaves when provoked. Still have the stock front sway installed too

Yeah, I'm a bit puzzled by the camber. I've seen anecdotal evidence saying that stock should be about -1.5, but I've seen conflicting reports on what the actual stock spec is. I doubt my car is "defective," because both sides were perfectly matched. Camber would only be out of spec if something was slightly bent, it's not like it's a Lada or something with questionable manufacturing. I don't want to get another alignment, but I might have to solve the mystery.

As far as the driving manners themselves, I think I was expecting a much more radical change, like I've experienced on other cars. Ultimately, the difference is very subtle, which is surprising, but might be explained by the large handling effects imparted by the e-Diff which is obviously unchanged. I'll have to see how the car feels at an actual autocross.

[CSBM5]

Originally Posted by sholzer

What is everyone doing for wheels for the M2C? M2 CS got classed in AS and I'll probably run my car a bit just for fun but would like to get another set of wheels. I didn't see anything from Apex that would fit the street class rules.

I'm using OZ Hyper GT HLT wheels that are exactly the stock specs in width, diameter and offset. In addition they are lighter, about the same weight as the 763M but well over $1k cheaper than those (just over $2k for the set) and look decent.

I posted some pictures in this thread about them.

[JustAWhisper]

Originally Posted by JustAWhisper

Yeah, I'm a bit puzzled by the camber. I've seen anecdotal evidence saying that stock should be about -1.5, but I've seen conflicting reports on what the actual stock spec is. I doubt my car is "defective," because both sides were perfectly matched. Camber would only be out of spec if something was slightly bent, it's not like it's a Lada or something with questionable manufacturing. I don't want to get another alignment, but I might have to solve the mystery.

As far as the driving manners themselves, I think I was expecting a much more radical change, like I've experienced on other cars. Ultimately, the difference is very subtle, which is surprising, but might be explained by the large handling effects imparted by the e-Diff which is obviously unchanged. I'll have to see how the car feels at an actual autocross.

Update on the alignment issue. It turns out that Yokos are so sticky that the suspension indeed does not settle properly when weight returns. I just swapped wheels in prep for a local event tomorrow, and the wheels did not slide out like they normally would and camber was visibly worse than before jacking the car up. When I did the alignment we swapped the wheels on the lift to check fitment before doing the alignment itself, and while the suspension settles better when coming off a lift than a jack, I'm certain the camber we saw was not reflective of the actual camber. Design is -1.5 and my car is probably close to that. I'm OK with that since my E46 is about there after pulling strut pins. Using the alternate hubs may still be worth it if I decide to stay in Street class for a long time, though.

[JustAWhisper]

New question. After my first autocross weekend I was pretty pleased with the stock handling of the car, but I want to try a bigger front sway bar to reduce some of the front tire rollover. For some reason, all of the standard aftermarket options are comically overpriced or just don't exist for the M2 for some reason. Hotchkiss is decent, but doesn't have an option to buy just the front bar.

I noticed Whiteline has a reasonably priced front sway bar for the M3, but it lists it as only compatible with the M3/M4 and not the M2. Isn't the suspension geometry the same on all 3 cars? Has anyone tried that one?

[feconi]

Originally Posted by JustAWhisper

New question. After my first autocross weekend I was pretty pleased with the stock handling of the car, but I want to try a bigger front sway bar to reduce some of the front tire rollover. For some reason, all of the standard aftermarket options are comically overpriced or just don't exist for the M2 for some reason. Hotchkiss is decent, but doesn't have an option to buy just the front bar.

I noticed Whiteline has a reasonably priced front sway bar for the M3, but it lists it as only compatible with the M3/M4 and not the M2. Isn't the suspension geometry the same on all 3 cars? Has anyone tried that one?

Yes I am running the Whiteline bar on my M2C. It only lists fitment for M3/4 but I can confirm it fit on my M2C with no issue.

[Dean_Clevername]

Haven't tried the Whiteline, price looks good on that one. I bought the bullet and got the pair from Hotchkis before I had shaken down the car as it seemed like the de facto B street move. Still cheaper than just the Dinan front.

After a couple autocrosses stock with just RT660, I'm wondering if I need the bar, or at least what the benefit is. Understeer exists now, but I can work around it. Lot's of body movement in transition, but the car sticks as long as you get your steering in rhythm with the body movement. Car was quite balanced at faster trackcross speeds.

So dummy question: what's the upside/payoff with the front bar? Better transitional response, but I hear it increases understeer. I'd think that the bar would help reduce dynamic camber loss by reducing roll, but it doesn't sound like that is happening enough to offset understeer from the increase in effective front spring rate. There must be a benefit since it's the most common 1st M2 BS mod? I'm just an ape trying to understand what's sacrificed and what's gained overall. Messing with suspension dynamics makes my simple brain hurt

[feconi]

What RT660 setups are folks running for B-Street? I saw recent champ tour results an M2C did well against tough competition on the Falkens. Anyone have a recommendation on a B-street setup with these tires (stock wheel sizes)? I’m leaning towards the 660s over the A052 which for M2Cs seems limited to 255/35 & 275/35.

[JustAWhisper]

Originally Posted by Dean_Clevername

Haven't tried the Whiteline, price looks good on that one. I bought the bullet and got the pair from Hotchkis before I had shaken down the car as it seemed like the de facto B street move. Still cheaper than just the Dinan front.

After a couple autocrosses stock with just RT660, I'm wondering if I need the bar, or at least what the benefit is. Understeer exists now, but I can work around it. Lot's of body movement in transition, but the car sticks as long as you get your steering in rhythm with the body movement. Car was quite balanced at faster trackcross speeds.

So dummy question: what's the upside/payoff with the front bar? Better transitional response, but I hear it increases understeer. I'd think that the bar would help reduce dynamic camber loss by reducing roll, but it doesn't sound like that is happening enough to offset understeer from the increase in effective front spring rate. There must be a benefit since it's the most common 1st M2 BS mod? I'm just an ape trying to understand what's sacrificed and what's gained overall. Messing with suspension dynamics makes my simple brain hurt

I ended up buying a Hotchkis bar set as well. Despite the cheap price on the Whiteline, I'm pretty sure it's a solid bar and after doing some math, I estimate that it will be way too stiff even on the soft setting. Hotchkis should be very similar to Dinan, which starts at 57% stiffer and goes to roughly 200%.

Unfortunately, I did not get the bar in time to run the Champ Tour this weekend. However, I did poll my competitors (there were several M2's there) and I got a wide variety of responses. One front runner ran his Dinan bar on full stiff before upgrading his shocks (not sure what he does now, but it's apples and oranges once you change shocks), while another front runner swapped his bar back to stock overnight between Day 1 and Day 2.

In theory, the stiffer front bar will improve transitional response, which is helpful in autocross, especially slaloms. This is effectively reducing the time it takes for the suspension to resettle which makes it easier for the driver to maintain a proper racing line and get on the power quicker. On the flip side, a stiffer front bar will reduce peak grip up front which generally increases understeer and could actually make the car slower if the bar is too stiff. However, on strut cars it also reduces dynamic camber loss and mitigates that somewhat. It's a bit car dependent. My old E36 reacted extremely postively to a much stiffer front bar with noticeably improved front grip, while the E46 tended to understeer even with a mildly stiff bar.

I agree with your assessment that the M2 handles quite well right out of the box and doesn't need serious fixing. You may decide you prefer the stock setup. But you have the bar so you might as well try it. Sometimes it's more about changing the feel to make it more comfortable to drive fast than fixing a problem or making the car faster. I think the wide variety of setups I saw this weekend indicates that driver style/preference is probably a dominating factor here.

[JustAWhisper]

Originally Posted by feconi

What RT660 setups are folks running for B-Street? I saw recent champ tour results an M2C did well against tough competition on the Falkens. Anyone have a recommendation on a B-street setup with these tires (stock wheel sizes)? I’m leaning towards the 660s over the A052 which for M2Cs seems limited to 255/35 & 275/35.

The B-Street winner this past weekend was on Falkens. I did not catch his tire sizes, though.

[AlpinewhiteM2C]

Originally Posted by feconi

What RT660 setups are folks running for B-Street? I saw recent champ tour results an M2C did well against tough competition on the Falkens. Anyone have a recommendation on a B-street setup with these tires (stock wheel sizes)? I’m leaning towards the 660s over the A052 which for M2Cs seems limited to 255/35 & 275/35.

I was going to try 270/30/19 fronts and 305/30/19 rears but the rears are on backorder until mid June . I decided to try the 270/30/19 front/ 275/35/19 rear set up, same as @Dean_Clevername. I also have a Hotchkis front bar so hopefully that helps keep the rear in line during corner exit since the M2C has a bit more low end torque than the OGM2s.

[Dean_Clevername]

Originally Posted by JustAWhisper

I ended up buying a Hotchkis bar set as well. Despite the cheap price on the Whiteline, I'm pretty sure it's a solid bar and after doing some math, I estimate that it will be way too stiff even on the soft setting. Hotchkis should be very similar to Dinan, which starts at 57% stiffer and goes to roughly 200%.

Unfortunately, I did not get the bar in time to run the Champ Tour this weekend. However, I did poll my competitors (there were several M2's there) and I got a wide variety of responses. One front runner ran his Dinan bar on full stiff before upgrading his shocks (not sure what he does now, but it's apples and oranges once you change shocks), while another front runner swapped his bar back to stock overnight between Day 1 and Day 2.

In theory, the stiffer front bar will improve transitional response, which is helpful in autocross, especially slaloms. This is effectively reducing the time it takes for the suspension to resettle which makes it easier for the driver to maintain a proper racing line and get on the power quicker. On the flip side, a stiffer front bar will reduce peak grip up front which generally increases understeer and could actually make the car slower if the bar is too stiff. However, on strut cars it also reduces dynamic camber loss and mitigates that somewhat. It's a bit car dependent. My old E36 reacted extremely postively to a much stiffer front bar with noticeably improved front grip, while the E46 tended to understeer even with a mildly stiff bar.

I agree with your assessment that the M2 handles quite well right out of the box and doesn't need serious fixing. You may decide you prefer the stock setup. But you have the bar so you might as well try it. Sometimes it's more about changing the feel to make it more comfortable to drive fast than fixing a problem or making the car faster. I think the wide variety of setups I saw this weekend indicates that driver style/preference is probably a dominating factor here.

Vegas CT BS lineup looked great, was eyeing the results last night. Seems like Supra/M2/M2C all have a shot this year. Will just come down to driver and prep.

Thanks for the thoughts on sways, mirrors my own experience in prior cars with dynamic camber loss. Will have to just swap it on and try it out. I definitely feel this car doesn't need more understeer, but transitional response will be crucial if Im able to register for the Finger Lakes Champ Tour. From videos it seems like that event is heavy on transitions. Shocks might be the best answer to be honest. You can valve them to give them good transitional response without sacrificing grip or overall balance. Or so Strano says, I know nothing of this sort of thing haha. Not a lot of off the shelf shocks available for the OG M2. Anyone know if the shock mounts are the same as other 2 series or are they from the F80?

FWIW locally I've had a couple events with Danny Kao in his 21 Supra (technically AS, but I'm not sure why it's bumped up vs the 20) on A052 (275 square). Both cars stock otherwise and I think the M2 has a slight edge TBH. Just for fun here they are side by side. I was late and picked up a +1 in the final slalom, but data says it actually cost me .2 from there through the finish vs my prior run so I still think my raw vs his clean run is an ok comparison.

[CSBM5]

Rear shock mounts are F8x M3/M4 parts; identical part numbers.