[eeyang92]

Hey all,

I was doing research and designing my own front splitter with brake ducts built in, when I stumbled upon something called splitter diffusers. I was familiar with front splitters, and rear diffusers, but never really thought how the front could benefit from a diffuser as well. I did a quick google search and found there wasn't really any discussion around this for the M2 so I'd thought I bring it up.

Here is the splitter diffuser in question: https://professionalawesome.com/prod...iffusers-pair/

The video they embedded on that site claims that by utilizing these diffusers, the downforce on the front splitter could be enough to tear it off if not secured properly. Keeping that in mind...

Like several others, I figured I could utilize the "empty" space beneath the bumper to fit brake ducts on either side. Example of the empty space on the bottom of the bumper from IND:



However, while I was looking for pictures of the underbody, I noticed something interesting:



It looks like the M2 underbody already has these splitter diffusers built-in! And, unfortunately, they are right behind the area where I would like to mount my brake ducts. I'm fairly certain if you weren't aware of the concept of splitter diffusers, you would think these are perfect ramps to route the brake ducts! I'm not knowledgable enough in this area to say how much effect this would have on downforce, but I figure it's safe to say you would lose some since the ducting would not only reduce the volume of the diffuser but also cause a bunch of turbulence. I also figure the effect of the diffuser is very real since BMW engineers saw fit to design the undertray with this particular feature.

I'm thinking I can route the brake ducting just to the right of the diffuser (in the picture above), but will lose some clearance from the ground by doing so, and my car is already lowered so we'll see if it's viable

[Megator]

Thoose ramps seem to be there to direct air towards the brakes more than to generate downforce.

I am by no means an expert though.

Curiously the M2C does not have them but does have brake duct in the front bumper. I can tell you from experience that an M2C is very stable at 160MPH.

https://ttw-installations.co.uk/prod...n-bmw-m2-2019/ (pics of an M2C underside)

If you want brake cooling I suggest something like this. There is more info in this section of the forum.

https://www.thingiverse.com/thing:3566812

[eeyang92]

Originally Posted by Megator

Thoose ramps seem to be there to direct air towards the brakes more than to generate downforce.

I am by no means an expert though.

Curiously the M2C does not have them but does have brake duct in the front bumper. I can tell you from experience that an M2C is very stable at 160MPH.

https://ttw-installations.co.uk/prod...n-bmw-m2-2019/ (pics of an M2C underside)

If you want brake cooling I suggest something like this. There is more info in this section of the forum.

https://www.thingiverse.com/thing:3566812

Interesting! I suppose the M2C shares a similar underbody as the M3/M4 due to the S55-specific parts.

I also wonder maybe the M2C doesn't need it because it may have a more aggressive front bumper (at least according to marketing, those 3 slots should provide some downforce)? I'm no expert either

Good find on the brake scoops, that might be much easier than routing ducts from the front to the wheel-well area, thanks!

[OG Shark]

Originally Posted by eeyang92

Interesting! I suppose the M2C shares a similar underbody as the M3/M4 due to the S55-specific parts.

I also wonder maybe the M2C doesn't need it because it may have a more aggressive front bumper (at least according to marketing, those 3 slots should provide some downforce)? I'm no expert either

Good find on the brake scoops, that might be much easier than routing ducts from the front to the wheel-well area, thanks!

Splitter tunnels ---> https://www.youtube.com/watch?v=g9HV9QtAx4M

[eeyang92]

Originally Posted by OG Shark

Splitter tunnels ---> https://www.youtube.com/watch?v=g9HV9QtAx4M

Super informative, thanks for sharing!