Karbonius Carbon Fibre Stock S54 Plenum

[maupineda]

That is a good solution, I tried spacing the tube with a grommet, and then used another grommet inserted into the tube slot to just seat there, it looks odd. I may just put back the CSL dipstick and be done with it. I am not a fan of putting tension on the carbon airbox either as with time, vibrations may do no good.

[maupineda]

I finally finished my installation. I struggled big time with getting the intake elbow to stay, it would constantly slip off, tightening the clamp did not help, actually made it worse as it would slip out even easier. But a bit of ingenuity and all is good.

I used antislip floor tape and it worked perfectly.



I also added rubber grommets to the dipstick tube, adding the nut in my opinion adds stress to the carbon box that I rather don't want.



And here is the final product







I may go back to the CSL dipstick.

I also tested the sound generator and it is loud, however, in the cabin the sound is a bit different and it masks the CSL warble a bit, but it does sound LOUD

And below the videos, this time I took it to redline. in the videos, the sound generator sounds nicer, but in the cabin is intense.

Karbonius-OE-Style-Eventuri+SG

https://youtube.com/shorts/fpJopJ7H8Hw

Karbonius-OE-Style-Eventuri

https://youtube.com/shorts/eQr-MuqgYVE

[C///M]

I also tested the sound generator and it is loud, however, in the cabin the sound is a bit different and it masks the CSL warble a bit, but it does sound LOUD

And below the videos, this time I took it to redline. in the videos, the sound generator sounds nicer, but in the cabin is intense.

Great job. Looks amazing in the Z4. What is the sound pipe/sound generator you mention? Did you put a pipe through the firewall to transmit intake noise into the cabin?

I miss an easy to access dipstick with my CSL box and dipstick. I stuck with the shorty CSL setup because I was silly and wanted to build a true "CSL replica". But honestly I don't know what BMW was thinking with the little dipstick, it's such a pain.

Curious if there is more clearance under the OE version of the Karb Airbox for the 3D Design power steering reservoir expansion tank. I have one I've been meaning to test with the Karbonius CSL Airbox.

Sent from my Pixel 6 Pro using Tapatalk

[maupineda]

Great job. Looks amazing in the Z4. What is the sound pipe/sound generator you mention? Did you put a pipe through the firewall to transmit intake noise into the cabin?

I miss an easy to access dipstick with my CSL box and dipstick. I stuck with the shorty CSL setup because I was silly and wanted to build a true "CSL replica". But honestly I don't know what BMW was thinking with the little dipstick, it's such a pain.

Curious if there is more clearance under the OE version of the Karb Airbox for the 3D Design power steering reservoir expansion tank. I have one I've been meaning to test with the Karbonius CSL Airbox.

Sent from my Pixel 6 Pro using Tapatalk

The Z4 chassis has a firewall opening for this purpose, the 3.0SI version had this sound generator pipe, and a guy from Germany built a version for the Z4M. the image below shows where it goes. in the photo below you can see it connects to the elbow, and from there to the firewall through a grommet.

[///MBan]

I'm not sure if this is an issue for the E46 guys, but Z4M users have found that the factory rubber intake elbow slips off the opening to the plenum. People have used tape to stop this from happening but Karbonius now has a permanent solution. From Karbonius:

"We have developed a solution for the slipping of the tube
Can tell the people on the group they can ask for a kit and we will ship
It includes glue and a laser 3D printed nylon frame"

Pictures below.

[JDMaflac]

Designed a super basic bracket for the oil dipstick, because my aluminum screwed together L brackets unscrewed from all the vibrations and started clanging against each other every once in a while. Super annoying!

I hosted the file on my site listing for folks with a printer. Not super motivated to print these out for people because of how small they are and how basic the design is, but can do so for anyone needing one.

Ordered 1

[JDMaflac]

I finally installed my Karb OEM airbox 2 weeks ago after running my Eventuri intake for a few months to get acquainted with the sound (other mods: euro headers, X Rasp section 1, stock section 3). I wanted to make sure my installation went correctly since I had to use worm clamps on the manifold side and didn't want to snug up too much on the carbon fiber piece so with the help of a friend we did a smoke test. Found out in the shared video that both bottom corners of the airbox itself leaks, granted the engine doesn't throw any lean codes but I feel like there's a slight hesitation/choke in the upper rev range (no custom tune other than CSL tune to accommodate for the headers). I wanted to see if anybody else have ran similar tests and if I should should reach out to Karbonius themselves? Another question I have, what type of impact would this have with unmetered air being sucked in, if any?

[maupineda]

I had this concern when I inspected my box, and I was 90% certain it was not air tight, that said, my car has been custom map and I don’t notice any issues, but my map for sure addresses any extra air via fuel trims, and all within the ecu failsafe as I don’t have any check engine light, even before mapping. I also noticed zero change in performance from my CSL Karb, so I am sure I am not missing anything other than the wonderful sound, but I also no longer have the lumpinesses I had with the CSL setup.

that said I kept my CSL and OE air box if I ever want to go back to either

[RazorM]

I had this concern when I inspected my box, and I was 90% certain it was not air tight, that said, my car has been custom map and I don’t notice any issues, but my map for sure addresses any extra air via fuel trims, and all within the ecu failsafe as I don’t have any check engine light, even before mapping. I also noticed zero change in performance from my CSL Karb, so I am sure I am not missing anything other than the wonderful sound, but I also no longer have the lumpinesses I had with the CSL setup.

that said I kept my CSL and OE air box if I ever want to go back to either

What do you mean by “lumpinesses” when you ran CSL airbox? Did you run on alpha n or map?

[maupineda]

Is a Z4M, so only option is Alpha-N.

[TeddybearCup]

I finally installed my Karb OEM airbox 2 weeks ago after running my Eventuri intake for a few months to get acquainted with the sound (other mods: euro headers, X Rasp section 1, stock section 3). I wanted to make sure my installation went correctly since I had to use worm clamps on the manifold side and didn't want to snug up too much on the carbon fiber piece so with the help of a friend we did a smoke test. Found out in the shared video that both bottom corners of the airbox itself leaks, granted the engine doesn't throw any lean codes but I feel like there's a slight hesitation/choke in the upper rev range (no custom tune other than CSL tune to accommodate for the headers). I wanted to see if anybody else have ran similar tests and if I should should reach out to Karbonius themselves? Another question I have, what type of impact would this have with unmetered air being sucked in, if any?

Contact Karbonius. I had a leak from the upper seam where the two halves connect and it was enough to require our car to have 10% STFT on lower loads and run a bit poorly from having to make the adjustments.
I believe the ECU can handle around 20 or 25% fuel trim adjustments before it gets truly problematic, but the adjustements are reactive so you get slightly worse operation as a result.

I ran a smoke test as well for this and sent it to Karbonius. They sorted me out after I shipped back the airbox. New airboxes are smoke tested before shipping as a result of my interactions with them, but the early ones were not.
Unmetered air getting sucked in means an underreading MAF, leading to the car having to increase fuel trims.

[JDMaflac]

Contact Karbonius. I had a leak from the upper seam where the two halves connect and it was enough to require our car to have 10% STFT on lower loads and run a bit poorly from having to make the adjustments.
I believe the ECU can handle around 20 or 25% fuel trim adjustments before it gets truly problematic, but the adjustements are reactive so you get slightly worse operation as a result.

I ran a smoke test as well for this and sent it to Karbonius. They sorted me out after I shipped back the airbox. New airboxes are smoke tested before shipping as a result of my interactions with them, but the early ones were not.
Unmetered air getting sucked in means an underreading MAF, leading to the car having to increase fuel trims.

Thanks Teddy!! I had sent them an email yesterday so waiting to hear back with what they say, not looking forward to removing the airbox again but will if I have to. May I ask what was the turnaround time and if you were responsible for any fees/shipping/VAT?

[TeddybearCup]

Thanks Teddy!! I had sent them an email yesterday so waiting to hear back with what they say, not looking forward to removing the airbox again but will if I have to. May I ask what was the turnaround time and if you were responsible for any fees/shipping/VAT?

I believe shipping was a couple of weeks and Karbonius helped organize it. I can't remember if I paid any fees (if there were, it wasn't anything scarring), and would certainly have that conversation fresh with Karbonius if I needed a fix.
They provided good support and stood behind their product.

[jpy1980]

Any updates on this? Has the issue with the intake elbow slipping off and the leaky box been addressed in the newer models?

[maupineda]

Yes. They have now a ring. I had mine replaced under warranty and the new one fixes all the issues.