3D Printed Carbon Fiber Polycarbonate Intake (Louder intake noise)

[Albino09]

I currently have the OEM elbow but would probably look to upgrade to a silicone one in the future to pair with this intake, is it necessary to buy the intake piece to match the intake elbow? The website doesn't show a clear side-by-side of what is different in the fitment.

[BigRussia]

Very cool project, and man does its sound great! My car came with the K&N 79 (or whatever the number is) Intake system + ECS silicone elbow, it sounded great for what it was but yeah i felt like the MAF was getting bad readings due to the turbulent air flow from the KN filter, had random idle stumbles too. So ended up switching to stock intake to smooth up the car and eliminate the potential heat-soak the KN would get (though I rarely sat in traffic). While the stock intake box is already a good design and car runs great with it (threw an aFe Dry S filter in there) I do miss the induction noise from the KN intake!

I was interested to buy this as a fun wknd swap project to get some induction noise back, and when I saw you also include a filter with it I was sold! I'm buying the silicone elbow fitment version now. Cool stuff man and I like supporting community helping projects like this, I'm looking forward to giving any feedback if any to help improve the design though already looks pretty well thought out and done!

PS. my car has a stupidly loud exhaust setup since mostly sees track these days (catless + no resonators BW single exit), so curious to see if the induction noise will be loud enough to be noticeable within the cabin. Also do you think the Karb stock manifold you have contributed to the loud induction sound in your video captures? I just recently installed the N15Design center hood vent so maybe that'll contribute a bit to the induction sound heard outside the car though ha.

EDIT: I somehow didn't think how this will be lighter than the stock intake setup! Another great benefit for me as I've been desperate to shave down front end weight since most of my car's weight reduction has come from the rear making the F/R balance pretty skewed lol. More info: I have the ECS silicone elbow currently but may install this intake w/ a new Bimmerworld silicone elbow I have as backup since the ECS one is prob a bit out of shape by now (so can give you fitment feedback on those). Lastly, my TTFS dyno tune was done when my car still had the K&N intake setup, so I might actually feel an improvement with this intake (though its been running just fine with the stock intake in the 2+ years switching to stock). Also you ROCK for free shipping! 👍

[DamnYank]

Any thoughts on heat shielding for the filter to minimize hot under hood air getting pulled in?

[TeddybearCup]

I currently have the OEM elbow but would probably look to upgrade to a silicone one in the future to pair with this intake, is it necessary to buy the intake piece to match the intake elbow? The website doesn't show a clear side-by-side of what is different in the fitment.

Not absolutely necessary, just a nice taper at the end to transition to the elbow a bit better. The difference isn't drastic, but I'd go ahead and order the one made for the silicone elbow, if I had plans to switch. Good reminder for me to update pictures to show the difference btw!
FWIW, the OEM elbows are louder than the silicone ones (lighter, and plastic reverbs more I think), just maybe? a bit worse flow due to being less smoother and a bit smaller. The transition with the OEM elbow setup matches how Eventuri and Gruppe M and any intake that can still use the OEM elbow is.


BigRussia You'll get the induction noise back and more! (def louder than k&n. That's where I started too.)
Looking forward to all feedback you can give! What I like about 3D printing is I can tweak as I get feedback, and I'm not thousands of dollars invested in a mold. if I think it'll be better, I'll make the change! Case in point: Someone told me on FB that their elbow was super hard to install with this. My Macht Schnell was easy, but theirs was slightly smaller, so I'll be shaving a mm off the diameter at that end to make things easier.

On exhaust:
The BW single exit will PROBABLY drown this out. From what I've heard, that setup is super loud. If you do hear the difference over that, I definitely want to know!
I think the Karb box helps but testing with a friend with the stock airbox and an earlier revision, that got a lot louder too. The differences between my original design with just a MAF housing and a premade velocity stack and the final where I have the horn shape is immense, and without a doubt the majority of the sound I hear.

On the BW elbow:
FYI it requires trimming in general. Macht Schnell didn't for me. I returned the BW one.

Because the intake is so light, (sub 2lbs with the box and bubble wrap) it's cheap enough to ship that I don't worry about it!

DamnYank
Yeah! So I've been testing a bunch. At speed (30mph), the delta between IAT and ambient is just 3-6 degrees (larger when it's super cold outside (-15F), smaller difference which it got warmer (+32F ish) From my research, similar to Eventuri and even OEM due to airflow. And from trends sub freezing, I'm hopeful the IAT difference is even lower at summer temps.
But when I idle at a stop, IATs do go up. I have a shield coming in (today) I'll be testing to see if the shield makes any difference in either scenario. If it does, I'll design one as an optional add-on. Should be sub $100 though I haven't designed and gotten quotes yet (I won't be 3d printing a shield due to size).

[BigRussia]

You'll get the induction noise back and more! (def louder than k&n. That's where I started too.)
Looking forward to all feedback you can give! What I like about 3D printing is I can tweak as I get feedback, and I'm not thousands of dollars invested in a mold. if I think it'll be better, I'll make the change! Case in point: Someone told me on FB that their elbow was super hard to install with this. My Macht Schnell was easy, but theirs was slightly smaller, so I'll be shaving a mm off the diameter at that end to make things easier.

On exhaust:
The BW single exit will PROBABLY drown this out. From what I've heard, that setup is super loud. If you do hear the difference over that, I definitely want to know!
I think the Karb box helps but testing with a friend with the stock airbox and an earlier revision, that got a lot louder too. The differences between my original design with just a MAF housing and a premade velocity stack and the final where I have the horn shape is immense, and without a doubt the majority of the sound I hear.

On the BW elbow:
FYI it requires trimming in general. Macht Schnell didn't for me. I returned the BW one.

Because the intake is so light, (sub 2lbs with the box and bubble wrap) it's cheap enough to ship that I don't worry about it!

Yeah not only is the BW exhaust setup itself very loud but I have the rear seats deleted as well 😅 I do at least have the HARD Motorsport delete fill panel, I had to trim it down to fit my car and its very thin aluminum, but it seemed to help a tiny bit with cabin NVH. Def better than just the open gap into the trunk (which is also stripped)! So if I end up hearing any new in cabin induction volume at all with your 3D intake then that'll be a huge selling point for your design I would say!

I too was curious if the harder plastic OE accordion elbow produced more volume compared to the silicone elbows, since silicone is more soft I was thinking they might not reflect sound as much, so thanks for touching on that point. Also thanks for the heads up about the BW silicone elbow, I'll first try installing the 3D intake with the ECS one I currently have on. Looking forward to digging into this and testing it.

[Albino09]

Is your 3D printer stage big enough that couldn't produce the elbow and MAF housing as 1 piece? Then you could maintain flow through the whole piece, as well as set the best material thickness for sound attenuation.

[TeddybearCup]

Is your 3D printer stage big enough that couldn't produce the elbow and MAF housing as 1 piece? Then you could maintain flow through the whole piece, as well as set the best material thickness for sound attenuation.

Unfortunately not, though I'm considering building one that can! (The current commercial options don't satisfy me for print quality vs cost at the size) It'll be a much tougher piece to print due to the bend and getting the material printed well but agree it'd be awesome.

After I get a heat shield working, I want to start on something for a 2 piece design that can include the upper elbow to prove the concept on my car. Same idea: smoother transition, lower weight, stiffer walls than stock and silicone elbows.

Edit:
Oh boy, so I had ordered a cheap aftermarket shield from ebay and it was so far off from working that in the end, I cut everything apart such that it was just one bent vertical wall between the radiator and the intake. Interestingly, it made IATs and recovery from a stop worse. I think it ended up diverting more hot air towards the intake due to not fully reaching the front of the radiator

I suspect I'll need a shield system that is closer to a full enclosure than just a partition, or a much more tightly designed shield.

[Albino09]

Looking at the Eventuri heat shield setup makes me think the intake scoop up into the shielded area is perhaps more critical than the shielding...but I could be wrong. Might be worth a test since the scoop is smaller than this intake piece.

Eventuri

[TeddybearCup]

It wouldn't help when stopped due to no air flow, but I'll test before and after once moving!

https://vortex-performance.com/shop/bmw/bmwe46e8x/e46m3airscoop/

These guys make a super affordable version I'll try out.
I haven't felt the car bog down, but would love to always have cold air at autocross. Thinking a fan pulling in air from the bumper as a fallback if I can't get a more sealed solution.

[Albino09]

It wouldn't help when stopped due to no air flow, but I'll test before and after once moving!

https://vortex-performance.com/shop/bmw/bmwe46e8x/e46m3airscoop/

These guys make a super affordable version I'll try out.
I haven't felt the car bog down, but would love to always have cold air at autocross. Thinking a fan pulling in air from the bumper as a fallback if I can't get a more sealed solution.

That $28 scoop is definitely the way to go.

[meowth]

Have had this piece on since early March so I’ve gotten to know it pretty well. It’s transformed the car enough to appreciate a notable difference in intake tone and volume. Hats off to OP for the R&D and hooking forum members up early. The print is strong and high quality, and looks right at home in the engine bay. Expectedly, there are downsides, but I have found they aren’t significant enough for me to take it off.

Bad news first, this thing is literally a hot air intake.
-Noticeably hotter to the touch after a nice drive than the stock piece. (Much thinner material, no ducting)
-Until a bracket is made for this it is held solely by the intake elbow and will move and bounce with the car’s motion. Heat shield could help keep it in place and improve temps.
-sometimes sometimes a bucking effect, a hesitation if you will. Assuming this is from losing my tubes feeding directly to fresh air.

-anyone should be able to discern these downsides solely from the pics. We all know what an intake that looks like this does. We all know the stock air box is as good as it gets in terms of reliabilityerformance. I really bought it for the promises of more sound (and because I love DIY developments) and it has truly delivered in that regard.

It’s really no question of what the e46 m3 needs, and that’s a carbon air box. If one can’t eat that cost this is possibly the most cost effective way to get a taste. It sounds good enough that I’m feeling that cliche “can’t stop going WOT” feeling from when I first got the car. It feels so much more alive. It’s a fine piece that has really expanded my enjoyment of this car. One of the most significant changes to my experience for fcab money.

[bigjae46]

The intake needs baffling to prevent hot air from under the hood getting into the intake.

Air flows from high to low pressure. The engine bay is a high pressure region when moving at speed. There will be a pressure differential from the lower pressure cooler air coming in. So the hot high pressure air is going to go through the intake into the low pressure region behind the filter. The intake won’t see cooler fresh aor until the under hood air pressure drops below the pressure of the fresh air.

Short version - the intake filter should be sealed off from the rest of the engjne bay to achieve optimal results.

[Albino09]

Maybe there is a way to combine this intake with a cap to the radiator upper ducting to simulate a low-cost Gruppe-M intake? I wish I had an autoCAD setup that I could get involved in putting something together as this issue is far from rocket science and I see a lot of potential with the 3D printed plastics.

[bigjae46]

Maybe there is a way to combine this intake with a cap to the radiator upper ducting to simulate a low-cost Gruppe-M intake? I wish I had an autoCAD setup that I could get involved in putting something together as this issue is far from rocket science and I see a lot of potential with the 3D printed plastics.

You could 3D scan the area but the challenge is going to always be getting a tight seal against the bottom of the hood. Which is why the OEM intake usually has better real world performance than most CAIs.

[Arith2]

If I didn't have a carbon airbox, I'd run this. It may be a hot air intake but this captures why most of us drive our cars, the enjoyment of it. The K&N, as bad as it was for performance, sounded really good. This is purpose built so I assume it sounds much better. Good job OP