Does anyone know who makes the OE CSL intake flap?

[Ramps]

Recently the CSL airbox snorkel with the flap has been out of stock and/or on back-order everywhere, and the price jacked from around $425 USD (it's been the same price for 5+ years) to anywhere from $1200-2400 USD. I presume the sudden price increase is because it's hard to get now?

Does anyone know who makes that part for BMW? Has anyone heard if it's discontinued or just between production runs? I'd wanted to do a Karbonius box over winter with the working flap but if it's crazy money and hard to get, I'll just order the Karb snorkel instead.

TIA

[C///M]

Genuinely not trying to be a dick, but if you actually find who makes it, run far away. The motor mechanism is a giant piece of hot garbage.

I wanted the OE snorkel because I wanted to build a true-to-spec CSL... and big shock, the flap motor lasted less than a year. And like 2k miles on a brand new unit.

I pulled it off, installed the Karbonius carbon snorkel, disabled the flap and couldn't be happier. The OE snorkel is surprisingly pretty hefty, so going with the carbon saved a chunk of weight and there is zero point of having the flap. Even with all the OE intake ducting, I couldn't notice any difference in low-end torque after the flap was disabled and removed (stock cams at the time, now 288/280 so no amount of intake runner tomfoolery is going to help this car under 3k 😂) and you definitely want to hear the airbox at all times. It's intoxicating. The only thing that bothers me is now having a connector dangling off not doing anything that I went through the effort of actually wiring to the DME.

BMW themselves have said the flap was 99% to do with noise control, but it's been a long time since diving into all the CSL research, so can't recall any actual data.

I still have it in my parts bin, been meaning to take the mechanism apart to see what fails.

Sent from my Pixel 6 Pro using Tapatalk

[Obioban]

Yeah. Flap is only worse.

[repoman89]

Genuinely not trying to be a dick, but if you actually find who makes it, run far away. The motor mechanism is a giant piece of hot garbage.

I wanted the OE snorkel because I wanted to build a true-to-spec CSL... and big shock, the flap motor lasted less than a year. And like 2k miles on a brand new unit.

I pulled it off, installed the Karbonius carbon snorkel, disabled the flap and couldn't be happier. The OE snorkel is surprisingly pretty hefty, so going with the carbon saved a chunk of weight and there is zero point of having the flap. Even with all the OE intake ducting, I couldn't notice any difference in low-end torque after the flap was disabled and removed (stock cams at the time, now 288/280 so no amount of intake runner tomfoolery is going to help this car under 3k 😂) and you definitely want to hear the airbox at all times. It's intoxicating. The only thing that bothers me is now having a connector dangling off not doing anything that I went through the effort of actually wiring to the DME.

BMW themselves have said the flap was 99% to do with noise control, but it's been a long time since diving into all the CSL research, so can't recall any actual data.

I still have it in my parts bin, been meaning to take the mechanism apart to see what fails.

Sent from my Pixel 6 Pro using Tapatalk

All of this. I switched from the flap to a race style unfiltered section myself and don’t miss it at all. Certainly don’t need the extra complexity or weight up front doing nothing but waiting to fail. Like you I also wish I hadn’t bothered with the DME wiring. It was a decent chunk of the difficulty and expense of the conversion.

[Ramps]

Genuinely not trying to be a dick, but if you actually find who makes it, run far away. The motor mechanism is a giant piece of hot garbage.

I wanted the OE snorkel because I wanted to build a true-to-spec CSL... and big shock, the flap motor lasted less than a year. And like 2k miles on a brand new unit.

I pulled it off, installed the Karbonius carbon snorkel, disabled the flap and couldn't be happier. The OE snorkel is surprisingly pretty hefty, so going with the carbon saved a chunk of weight and there is zero point of having the flap. Even with all the OE intake ducting, I couldn't notice any difference in low-end torque after the flap was disabled and removed (stock cams at the time, now 288/280 so no amount of intake runner tomfoolery is going to help this car under 3k 😂) and you definitely want to hear the airbox at all times. It's intoxicating. The only thing that bothers me is now having a connector dangling off not doing anything that I went through the effort of actually wiring to the DME.

BMW themselves have said the flap was 99% to do with noise control, but it's been a long time since diving into all the CSL research, so can't recall any actual data.

I still have it in my parts bin, been meaning to take the mechanism apart to see what fails.

Sent from my Pixel 6 Pro using Tapatalk

LOL I appreciate your honesty and I can't say you're wrong. I'm totally aware of the reliability issues but I've been still leaning towards 'finding out the hard way' you could say. I'm in my mid-40's and like the idea of being able to keep things quiet at times. The reason I'm interested in who makes it is because I have a feeling the snorkel is likely a random injection molder BMW uses for other parts and the position sensor and motor could be from other OEM vendors and could be off-the shelf parts...I haven't had my hands on a unit to really get a good look. I'd like to figure out what fails and see if there's an alternate part, I'm an industrial designer so it wouldn't be hard to design and 3D print an adapter if I had to, to retrofit a reliable actuator.

Let me know if you want to sell your busted one real cheap

[Obioban]

The CSL intake, without snorkel, is quiet if you’re not in the throttle.

[Cubieman]

The actuator motor is used for different purposes on other vehicle, thinking I'll buy a 2nd, or a 3rd.

11617511383

[usdmej]

Even with all the OE intake ducting, I couldn't notice any difference in low-end torque after the flap was disabled and removed

if you looked at how and where the CSL ducting is routed, it's pretty clear that power gains were not the intention of that setup

[usdmej]

I'm totally aware of the reliability issues but I've been still leaning towards 'finding out the hard way' you could say. I'm in my mid-40's and like the idea of being able to keep things quiet at times.

i'd say go for it especially if your setup allows for it. the flap with ducting makes around time driving so much stealthier, so that when you do open it up the roar is all the more enjoyable. i live in an area where every other car is a tesla so i don't want to be barking at people just trying to keep up with the flow of traffic

[Ramps]

if you looked at how and where the CSL ducting is routed, it's pretty clear that power gains were not the intention of that setup

Agreed, it looks like the primary purpose was for sound control which is the main purpose of the flap itself, and the secondary purpose is to get fresh air behind the flap while sitting in traffic. Both good things, at the cost of making it a more complex system.

[crow4213]

The CSL intake, without snorkel, is quiet if you’re not in the throttle.

True, you can't even really hear it until 3.5 - 4k and not unless you are near WOT

[repoman89]

i'd say go for it especially if your setup allows for it. the flap with ducting makes around time driving so much stealthier, so that when you do open it up the roar is all the more enjoyable. i live in an area where every other car is a tesla so i don't want to be barking at people just trying to keep up with the flow of traffic

I don't really get this. With a stock muffler and flapless carbon intake, the car is perfectly stealthy just keeping up with traffic and driving around town.

Coming from someone who doesn't like loud cars or attention. I did the flap in the first place thinking it would keep things calm when needed .. but it's already calm unless you are driving like a typical BMW driver, in which case you might as well make some noise to warn pedestrians and other drivers that you might spin off the road at any second.

[Ramps]

I don't want this to turn into a "is the flap worth it" debate...I am sure it's not for most people, but I just want to try it for myself if I can get my hands on one.

I'm guessing no-one knows the answer to my original question? We know who makes the Original Equipment for suspension bits, filters, and even the original CSL airbox...I guess the flap assembly is a bit more obscure.

[usdmej]

I don't really get this. With a stock muffler and flapless carbon intake, the car is perfectly stealthy just keeping up with traffic and driving around town.

Coming from someone who doesn't like loud cars or attention. I did the flap in the first place thinking it would keep things calm when needed .. but it's already calm unless you are driving like a typical BMW driver, in which case you might as well make some noise to warn pedestrians and other drivers that you might spin off the road at any second.

as others have said, you can keep the car quiet by driving slowly (duh), and i also prefer a quieter car in general, but there are a some instances where without a flap, you'll be making more noise (drawing more attention to yourself) than you probably want to compared to if you had the quieter setup. when i was flapless, i all but gave up trying to beat red lights because i didn't want to be "that car" roaring across a yellow. same for if you wanted to close the gap on a driver that was clearly going to try to change lanes and squeeze in front of you forcing you to slam on your brakes. everyone's driving conditions will differ, but this has been my experience.

and again, when you do get the flap open, it's just as glorious of an experience (if not more so) when it happens