[DutchBoysRacing]

Hey all,

I have a 2024 M2 Carbon package that I track pretty heavily in Southern California.

Current mods:
- 19x11 square apex wheels / 305/30/19 Supercar3R
- Millwood Camber Plates
- No rear seats

My current findings are that even while using the super sticky 100tw tire on track is that even with the Millwood camber plates maxed out to ~3.3 degrees front / 2.5 rear. Looking at my tire wear it seems that I am using about 50-60% of the front tire, and about 70% of the rear tread due to how soft everything is.

I'm hoping the CSL Sway bars can add some rigidity to the front and rear end but will report back after 5/12 as thats my next track event at Streets of Willows Springs.

[maxwell smart]

Are you using a tire pyrometer to check the settings you are using .
I'm at -2.5 front and -1.8 rear camber and my readings and wear are looking pretty good. The amount of grip I had last weekend with cup 2 R tires was insane.
What pressure are you running in the tires at the end of a session.
I just ruined a set of cup 2 R tires letting them get to 39 psi , and corded them in the middle of the tread, not at the edge.

[maxwell smart]

Also i wanted to ask how your experience is going without the rear seat .
last year I pulled mine out and did six track days , but I found the vehicle had a severe case of wind buffet in the interior so bad people in the pits would ask what was up. you could hear the buffeting throughout the whole property, it was pretty crazy, i think it was slowing the car down. I reinstalled the seat in the fall and left it in and up to start this season and found the buffet had disappeared and the vehicle is way easier to drive on course.

[DutchBoysRacing]

Originally Posted by maxwell smart

Are you using a tire pyrometer to check the settings you are using .
I'm at -2.5 front and -1.8 rear camber and my readings and wear are looking pretty good. The amount of grip I had last weekend with cup 2 R tires was insane.
What pressure are you running in the tires at the end of a session.
I just ruined a set of cup 2 R tires letting them get to 39 psi , and corded them in the middle of the tread, not at the edge.

I am not using a pyrometer. I am usually starting at 25 cold and getting to 32-34 hot. The wear is specifically from not enough camber or the suspension being too soft. Its over the outside edge so I could increase camber by adding SPL camber arms, trust arms, etc or try to stiffen the front and rear as much as possible.

The no rear seats sucks. As you've mentioned, due to the severe wind buffetting. It rattles my brain apart and really sucks, but since I'm mostly doing time trials I take all the weight savings I can. I haven't noticed the car handling "worse" with the buffeting my brain is probably getting the "blender treatment" on track.

I've also noticed its specifically bad with certain conditions. Some track days its not bad at all, and some days its almost unbearable.

[maxwell smart]

Are you sure your not running too low pressure. in the Michelin bulletin I found the cup tires are not supposed to be run lower than 29psi or case damage can occur. regardless of manufacturer I wonder if 25psi is letting the tire roll onto the sidewall.
check out a pyrometer, there's a good one made in America that's inexpensive and will pay dividends in the information that can be gained.

[LeggoRacing]

Following as I’m about to be in the same boat. Vorshlag camber plates and 19x11 with 3r

[maxwell smart]

Hello Leggo ,
I would look for a technical bulletin from goodyear with the parameters they would like that tire to be run at. That should help you make initial decisions on where to start with your setup. Then when your at the track use the pyrometer to make sure your using all the tread for maximum grip.
Im using millway plates and have them adjusted to 12mm inward to produce -2.5 front , it still has good road manners, and my tire wear at the track looks good.

[DutchBoysRacing]

Originally Posted by maxwell smart

Are you sure your not running too low pressure. in the Michelin bulletin I found the cup tires are not supposed to be run lower than 29psi or case damage can occur. regardless of manufacturer I wonder if 25psi is letting the tire roll onto the sidewall.
check out a pyrometer, there's a good one made in America that's inexpensive and will pay dividends in the information that can be gained.

Yeah I've run S9M/S8M slicks,RR, A055, A7, R7, CRS, RE71RS all around 25 PSI cold (depending on the weight of the car). I believe hoosier a7/r7 documentation states that their pressures should be ~40 hot (which no one does and is insane).

I don't have the luxury of tire warmers so i need to start them so low or they will get too hot on track. I've found after two laps (avoiding the rumbles) I get them to about 30-32 hot and can keep them there +/- 2 degrees. I've started the SuperCar3R at 25 PSI and have gotten them to 36 pounds hot if I don't have some cool down laps and push too hard.

The wear im getting def isnt from starting too low as I do significantly more laps at 32 psi than 25.

[DutchBoysRacing]

Fun update. I had EAS order me a front CSL sway bar and rear. Seems that BMW sent the wrong part and sent a Front CSL and Front M2/3/4 sway bar.

BUT we did some science...sort of.

It seems that the CSL (2nd photo) and non-CSL (3rd photo) sway bar are practically identical. Minus the position of where the hole for the end link enter. The CSL Sway bar seems to be ~1/5 of an inch lower than the non-CSL.

That being said, the bar itself could have been constructed differently so we decided to modify the CSL bar instead of the OEM one I had originally on the car...and if the modified CSL bar sucks, I can always go back to the stock bar.

Out of fear that it would only be marginally stiffer...and for the sake of science. We ended up adding an additional hole under the CSL bar to increase the stiffness. See the first photo.

I will report this Sunday when I hit Streets Of Willow, CCW with my findings.

[Lappy]

Originally Posted by DutchBoysRacing

Fun update. I had EAS order me a front CSL sway bar and rear. Seems that BMW sent the wrong part and sent a Front CSL and Front M2/3/4 sway bar.

BUT we did some science...sort of.

It seems that the CSL (2nd photo) and non-CSL (3rd photo) sway bar are practically identical. Minus the position of where the hole for the end link enter. The CSL Sway bar seems to be ~1/5 of an inch lower than the non-CSL.

That being said, the bar itself could have been constructed differently so we decided to modify the CSL bar instead of the OEM one I had originally on the car...and if the modified CSL bar sucks, I can always go back to the stock bar.

Out of fear that it would only be marginally stiffer...and for the sake of science. We ended up adding an additional hole under the CSL bar to increase the stiffness. See the first photo.

I will report this Sunday when I hit Streets Of Willow, CCW with my findings.

Do you have and side by side pictures or comparison showing how much shorter the middle thin section is compared to OEM. I'm "assuming" the CSL bar is stiffer as a result of a short thin section. Regarding drilling additional holes further from the end of the bar, I believe that will provide very little change due to the angle of the bar being more vertical than traditional setups we might all be used to. Curious to how it feels as the recently released HR bar is non adjustable (likely due to the vertical positioning of the end) and for 500 dollars is absurd ask imo.

[DutchBoysRacing]

Originally Posted by Lappy

Do you have and side by side pictures or comparison showing how much shorter the middle thin section is compared to OEM. I'm "assuming" the CSL bar is stiffer as a result of a short thin section. Regarding drilling additional holes further from the end of the bar, I believe that will provide very little change due to the angle of the bar being more vertical than traditional setups we might all be used to. Curious to how it feels as the recently released HR bar is non adjustable (likely due to the vertical positioning of the end) and for 500 dollars is absurd ask imo.

Hey Lappy,

So we (Nick & Steve @ EAS) took calipers and measured everything, unfortunately I did not ask them to take pictures until after we did the drilling. I took my wife to get sushi for lunch to get more "car spending tokens", so I wasn't at the shop the whole time.

There was no difference in any measurement of the bar (length, girth, width). The only noticeable difference was the flange where the end link meets, but that was due to the CSL bar having the hole slightly lower than the M2/M3/M4 bar. This made the flange appear larger on the non-csl bar but when measured it was the same length.

Just because the measurements are the same, the "stiffness" of the bar could be vastly different due to manufacturing differences (treatment of metal, hollow vs solid core, materials used, etc).

I would assume however, that BMW cut on costs and made one bar and just spaced the holes in different locations. To fit the CSL, M2, M3,M4.

Here are photos of the bar attached. Took it today when prepping the car for the track this sunday.