Karbonius Carbon Fibre Stock S54 Plenum

[JDMaflac]

Following this topic off of zpost but i'm excited to see the next iteration with the brace in place.

[terra]

That's a bummer - thanks for clarifying. So Z4Ms and post-2004 M3s will also need to buy the rubber couplings.

Post 10/2004 M3s specifically. And even then the cutoff is somewhere in the middle of the month. My 2005 M3 was built in early October 2004, and it had the old rubber couplings.

[///MBan]

They don't work.

That's a bummer - thanks for clarifying. So Z4Ms and post-2004 M3s will also need to buy the rubber couplings.

[repoman89]

Can anyone confirm if Z4 and post-2004 M3 rubber couplings work with the CSL airbox? I have never read that they DON'T, but would like to confirm as the rubber boots are quite expensive.

They don't work.

[///MBan]

Karbonius have come back with responses to my questions:

Q. There appears to be quite a lot of flex in the top of the plenum. People have expressed concern that this could result in the unit failing over time, probably where the two parts are bonded together. Is there a way to strengthen the top? Or do you think this isn't needed?

A. Yes, a lot of flex on the top, this is because this unit was made without the inner pilar reinforcement, we are installing a inner reinforcement ( like the ones we are using in the CSL airbox) and we will test again, I hope not to loose too much sound!! Anyway ,I´m not worried about the union between 2 pieces, I´m sure will not fail on this area, we are using a very good glue, it support a lot of cicles of flexion and traction

Q. Is it possible to order the plenum without any logo or writing on the top?

A. Yes , no problem, we could send it with the Mpower sticker separately ( not glued under the varnish)

I also asked about the rubber coupling and they advised that their plenum is designed to work with part number 11617830265. This is part from the CSL and pre-2004 M3.
https://www.realoem.com/bmw/enUS/pa..._CSL&mg=11&sg=40&diagId=11_3517&q=11617830265

Can anyone confirm if Z4 and post-2004 M3 rubber couplings work with the CSL airbox? I have never read that they DON'T, but would like to confirm as the rubber boots are quite expensive.

[///MBan]

Okay, so I have a couple of questions to ask Karbonius:
- can the plenum be strengthened so it doesn't flex so much?
- which rubber boots were used in the design (my understanding is that Z4Ms and post-2004 E46 M3s have one type of boot (part number 11617835861) and pre-2004 M3s and M3 CSLs have another kind (part number 11612466477) and they're not interchangeable. This also means the OE clips on the plenum side are different - Z4M is 11617835320 and pre-2004 M3/CLS is 11617830306)

Before I go back to Karbonius I want to check if anyone else has questions or comments?

S54Mickey
GemsZho
CheckA
jrgatfh
R717
9kracing
theBMWaddict
Jimm3

[maupineda]

this, plus my eventuri, plus my sound generator, I bet will be even better than my current Karb box, and no more Alfa-N ==> Win

[///MBan]

The intention was not to make any more power, just to give some of the CSL sound while keeping the MAF and not needing any kind of a tune. Adding 50% of the sound volume achieved with the CSL intake is pretty impressive to me when the standard airbox is still in place. I also really like the change in tone achieved with the carbon plenum. I suppose it's about expectations and some people will be happy with what has been achieved while others won't be. The flexing is something a few people have mentioned, so I'll see what Karbonius has to say about that.

[digger]

Imo it looks out of place having the oem plastic intake / airbox

[S3diment]

IMO, if you grab this and a new eventuri intake, you might as well just grab the Haimus Racing carbon airbox which runs about $1800 IIRC. Going with this and a new eventuri puts you easily over $2k for the full setup.

This project is awesome just simply because Karb took the time to even build one just because some E46 nerds were curious how it would come out haha. Great to see a company support enthusiasts on what’s now a 21 year old chassis with new parts.

The math isn’t as straightforward for those with MSS54 DME’s.

[Nate047]

So basically it's a little louder and makes the same power as stock, or am I missing something?

[LSBNick]

Not going to add anything of substance really with my comment, but I just wanted to say this is awesome. I'm sure everyone involved appreciates the communication and transparency. Karbonius created an entirely new product just to see how it turned out because some people on the internet were interested and that makes them seem even cooler to me than they already did.

I'm glad it actually worked. This + an eventuri might be the ultimate MAF setup. Also interesting to see the flexing of the carbon with the more restrictive intake path (compared to CSL).

IMO, if you grab this and a new eventuri intake, you might as well just grab the Haimus Racing carbon airbox which runs about $1800 IIRC. Going with this and a new eventuri puts you easily over $2k for the full setup.

This project is awesome just simply because Karb took the time to even build one just because some E46 nerds were curious how it would come out haha. Great to see a company support enthusiasts on what’s now a 21 year old chassis with new parts.

[///MBan]

Is it me or is that airbox flexing inwards?

There have been a few similar comments on other forums - I'll ask Karbonius about the flex.

[WoGGo]

Is it me or is that airbox flexing inwards?

I believe that is just the reflection of the lights above changing as the whole engine moves.

[simonnim]

Is it me or is that airbox flexing inwards?