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

[I M Legend]

Ok, major revision (actually, been working on about 10 different revisions over the last few weeks)

I tried the Eventuri filter, and eventually settled on the fact that the key is to have as light an intake setup as possible.
Even tried the Macht shnell elbow.

So here is the first version I'm super happy with. Fully ASA printed, just over 110g mass, with a very affordable filter.

The intake is much louder than before.

I have PC and nylon coming in, and I think I'll shoot for even thinner walls in PC next.

can you share the STL?

[Theraqa]

Sounds great but looks very short

[TeddybearCup]

I don't plan on uploading any files for this, but will note any interest in this with a goal of printing a final version very affordably. I'm still testing the largest effects on sound, whether it's wall thickness, material, shape, length or how smooth I sand the walls.

Length is pretty much capped by how long the engine bay is. Any longer and I'm hitting the front structure. Dunno if there is any benefit to length beyond getting the filter closer to fresh air at the front.
EDIT: Well, compared to the standard affordable intakes from K&N and AFE, I'm using a 6" filter vs 4" on the K&N. (I think AFE is 5"?) The front is much wider as a result, and that can look shorter in relation?

[PowerSax]

That looks way cool. Should be good for a future swap I am planning. count me as "interested".

[TeddybearCup]

Getting really close! I have polycarbonate printing now (basically what Lexan windows are made of), and it's a step above nylon in finish and a huge step up in temperature resistance. It'll survive a bit beyond 240F before it starts to deform! Since I track this car, more temperature resistance is nice to have. It's been a grail of mine to be able to print PC ever since I started 3D printing.

On tuning sound: I think sound is going to be best with a horn shape, as opposed to the bell/Eventuri-like curve. The more bell-like I made the shape, the deader and quieter the sound got.
From some research into horn sound theory, I concluded an exponential curve would be best. So today, I tested one with an exponential horn curve targeted around 6000 RPM for secondary engine frequencies. Well, it worked really well at amplifying those target wavelengths, but ultimately, because the wavelengths amplified were really similar to the tones produced by the exhaust, while it was louder, it was actually a less interesting sound than I've had before, in less calculated prototypes!

At this point, it'll be some tuning for what I think makes the best sound (I know, high subjective), with a shorter horn I hope to amplify a tertiary note with, to really provide contrast in the sound it makes.

EDIT: Went and tested a super short horn shape, made to amplify only higher frequencies. It got the more thrilling sound, but doing so I realized that the horn frequency tuning is for the lowest frequency that gets amplified. In a sense, it's like a high pass filter for the intake noise. In comparison, a longer horn that was shallow enough to get the firing frequencies of the engine was successful amplifying a broader range of sound, and ultimately ends up louder. So there are two viable designs: One that is all around louder and amplifies a larger range of sound, sounding fuller. One that is less loud but by amplifying just the higher frequencies, makes a slightly more exotic sounding note, that is more discernible from the exhaust sound.

[TeddybearCup]

Dunno if people are familiar with the Vortex MAF housing that is also 3D printed, but I had a friend with an S54 swapped E36 M3 with that plus the OEM manifold.
So here's a video comparing my design against the Vortex setup with a pod filter.
Keep in mind, that is already a lot louder than OEM.

The difference was pretty drastic in tone and volume. Vortex recording in the first half, my intake in the second.

Have another friend with an S54 swapped 318ti with both OEM manifold and a very cut up and modified OEM intake box to get a slighter better comparison with next!

I'm also happy to say my print quality even in polycarbonate was a big step above the Vortex piece And at the same time, my setup is significantly lighter!

[TeddybearCup]

Alright, I made a few further revisions and switched to an even stiffer filament: Carbon fiber infused polycarbonate.
This made the surface finish a pleasure to look at, and magnified the sound even more. It's finally at a state I'm proud of.

First prints coming with logo and a slightly more finished horn-end design, and I'll be making these available for anyone interested. (I have a small site at 3dwardprinting.com)
I'll have versions for both OEM elbows and silicon elbows. Unlike every other intake with a MAF housing that mates up to the silicone elbows, my design has a smooth transition to the larger inner diameter of the silicone tubing, getting rid of the abrupt square edge that introduces turbulence in the transition point. Meanwhile with the OEM elbows, the ID matches perfectly to the flex plastic ID, allowing as smooth of airflow as possible.

I also believe this is one of the lightest options available for someone using a MAF sensor (as in, not CSL intake). Even compared to the super tiny Vortex printed piece, this comes in significantly lighter.
Anyway, my wife keeps telling me her car is too loud now...But she likes it

[meowth]

Nice project, stuff like this is why this community rocks. Did you end up doing any kind of smoothing to your final design? Also, weight?

[TeddybearCup]

Nice project, stuff like this is why this community rocks. Did you end up doing any kind of smoothing to your final design? Also, weight?

Yup! I sand the inside with 400 grit sandpaper and then rinse out. The outside is untouched.
I actually never was able to discern any sound differences but the ocd in me wants the inside smooth.

The filter is 339 grams. The intake is 145 grams. I was able to get the intake down to 104 grams but added weight back in for strength some aesthetics.

For comparison, the Eventuri filter alone weighs 387 grams and I expect the carbon fiber housing, aluminum maf and rubber connecting piece weighs significantly more.
On a super early design, the cf velocity stack and rubber clamp weighed 262 grams. And that cf piece was many times smaller.

I forgot to actually link. I have this part available for ordering here:

https://3dwardprinting.com/collections/car-parts/products/e46-m3-s54-carbon-fiber-polycarbonate-intake-e36-m3-s54-swap-compatible

Intro discount since I'm trying to gather feedback during the winter. The final piece has my logo faintly below the maf.

[meowth]

Sweet thanks for the specs. I’m in for one! Been wanting to try something other than stock intake for a while so this will certainly be interesting.

[PowerSax]

Wow, you work fast.
Just ordered one. Can't wait to plug it in. Appreciate ALL your effort, and the early bird discount!

And, free shipping, even to Hawaii...

[EthanolTurbo]

I have an Eventuri and am willing to test and benchmark this. I also have high end recording equipment to capture the sound differences.

[TeddybearCup]

Will see if I regret that policy once I pack it up

I have an Eventuri and am willing to test and benchmark this. I also have high end recording equipment to capture the sound differences.

Hey, I'd love to get one in your hands! Message me here, or Facebook, or IG, or email at info@3dwardprjnting.com (whatever you prefer) and I'll work something out with you.

[PowerSax]

Already arrived. Great looking piece.
See any problem with painting the outside of the housing?
Hopefully this can go on soooon.

[TeddybearCup]

Already arrived. Great looking piece.
See any problem with painting the outside of the housing?
Hopefully this can go on soooon.

Thanks!
No, I wouldn't be concerned, though check into paint adhesion with polycarbonate and what paints work best.
The paint layer MIGHT change sound properties some (more mass). I haven't done any tests with painting. But as far as safety and whether it'd affect performance, no issues as long as it's just the outside and not inside, or within the MAF housing.