Karbonius CF reproduction of standard S54 plenum **PROTOTYPE VIDEO**

[NLW73]

yeah true matched with the Venturi front snorkel bit it would be very good indeed.

 

[///MBan]

Will this give any more bhp gains?

Or just for amazing looks and better sound for intake?

I wouldn't have thought any extra bhp hopefully some decent sound though. If it sounds good, paired with an eventuri could be epic

If this works, i wouldn't be surprised if evolve make something similar too.

I approached Eventuri as well but they said it didn't make sense for them to do the development for such an old platform. I'm really glad Karbonius didn't think that way!

 

[hopz121]

Will this give any more bhp gains?

Or just for amazing looks and better sound for intake?

I wouldn't have thought any extra bhp hopefully some decent sound though. If it sounds good, paired with an eventuri could be epic

If this works, i wouldn't be surprised if evolve make something similar too.

I approached Eventuri as well but they said it didn't make sense for them to do the development for such an old platform. I'm really glad Karbonius didn't think that way!

That’s madness, they are doing them for M5 / M6 V10’s and there wasn’t as many of those sold as E46’s. Maybe it’s the fact the E46 has quite a few different intake / airbox options already, or they know something Karbonius don’t and it doesn’t make much difference.

Have they told you when to expect the results?

 

[Matt.13]

Eventuri / Evolve already their own intake system and a csl style air box. Thats enough for them i suppose. They tend to concentrate their efforts into the new cars that are on the market.

 

[///MBan]

Karbonius has test-fitted the plenum and made a video, as well as videos of the same car with a completely stock intake and the same car with their CSL-style intake. I've posted the videos below. Karbonius are on holiday until 30 August but provided a few comments when they sent me the videos:

"I just sent you 3 videos,
1- OEM airbox, you can see the results in dB , minimum 72,2 and maximum at 5000 rpm 106 dB
2- CSL airbox , minimum 79 , maximum at 5000 rpm 130.2 dB
3 -Karbonius OEM style airbox, minimum 74,3 , maximum at 5000 rpm 118,7 db.

Sorry for the quality of the video, maybe doesn't´do justice comparing with real sound, but I think you can hear the difference between the 3 boxes.
We have 2 dB more in the low measure and +12,7 dB in the revolutioned measurement . The Karbonius OEm style airbox is not as louder as the CSL airbox, but clearly louder than the OEM one.
We checked on the car and drove few kilometers, and we could hear clear the sound of the box, specially between 2500 to 4000 rpm, driving at few rpm and putting gas in 4th or 5th gear is easy to heard."

I also asked a couple of questions:
Q. Will the price be the same as originally estimated (1,200 euro)?
A. Yes , at the moment we will keep the price, but I´ll confirm you when we will make the 2nd unit!

Q. How long will it take to put into production?
A. We can start the production in middle of September

Videos:
Karbonius carbon fibre S54 plenum
[youtube]https://youtube.com/shorts/NtCRPz1705A?feature=share[/youtube]

Karbonius CSL-style intake
[youtube]https://youtube.com/shorts/D8S_IVLXTEc?feature=share[/youtube]

OEM
[youtube]https://youtube.com/shorts/LV8jRFmXMyg?feature=share[/youtube]

 

[hopz121]

Interesting results, I’d be interested to hear the same with some drive by’s inside and outside of the car under load etc

I wonder what it would sound like with an Eventuri paired with it too

 

[///MBan]

Interesting results, I’d be interested to hear the same with some drive by’s inside and outside of the car under load etc

I wonder what it would sound like with an Eventuri paired with it too

I think Karbonius is going to send me the first production model so I can do some testing and report back. I have an Eventuri, so I plan to test both in isolation and both together.

 

[hopz121]

Interesting results, I’d be interested to hear the same with some drive by’s inside and outside of the car under load etc

I wonder what it would sound like with an Eventuri paired with it too

I think Karbonius is going to send me the first production model so I can do some testing and report back. I have an Eventuri, so I plan to test both in isolation and both together.

Awesome that would be great if you can, could you do some runs without it fitted too so we can see a reference with the Eventuri as the base case?

 

[///MBan]

Awesome that would be great if you can, could you do some runs without it fitted too so we can see a reference with the Eventuri as the base case?

That's my plan. I do already have some videos of the car completely stock and with the Eventuri but I think I have a better way to record the sound from inside the car, which will hopefully be more representative. So, I'll re-record all scenarios.

 

[///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?

The three z4-forum members I have on the list are below, but this forum doesn't seem to have a 'notify member' function?

@survivalist
@henderson_louie
@Justino

 

[///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.

 

[Jon2215]

Can only say that when my Geoff Steel airbox was fitted we had to change the rubber boots due to the later S54 having different diameter boots to the earlier variant.

 

[///MBan]

Can only say that when my Geoff Steel airbox was fitted we had to change the rubber boots due to the later S54 having different diameter boots to the earlier variant.

Thanks - I've had a couple of other people confirm the rubber boots are not interchangeable. Bit of a bummer given they're not cheap.

 

[MrPT]

Sounds really good - it has that depth to it which you don’t really get with just a carbon intake.

Do you know what the weight is? The OE plenum is about 5kg, which isn’t ideal given its location.

 

[///MBan]

Sounds really good - it has that depth to it which you don’t really get with just a carbon intake.

Do you know what the weight is? The OE plenum is about 5kg, which isn’t ideal given its location.

I actually haven't asked about the weight... a bit of an oversight on my part, so I will ask.

 

[///MBan]

Karbonius have added a 'pillar' to the plenum to reduce the flex and re-tested. Volume appears to be unaffected. Possibly there's a slight change in tone? Video below.

To plan a production run, Karbonius are asking for people to indicate if they intend to buy one. I'll start a list on zpost (https://www.zpost.com/forums/showpost.php?p=29291402&postcount=150). Don't forget that Z4 people and post-10/2004 M3s will need to buy the old rubber couplings and matching clips for the plenum side (parts 3 and 4 here https://www.realoem.com/bmw/enUS/showparts?id=BL96-EUR-10-2003-E46-BMW-M3_CSL&diagId=11_3517). Or, you can buy the Turner silicone coupling kit, which is quite a bit cheaper than buying new OE parts.

Karbonius plenum with extra reinforcing:
[youtube]https://youtube.com/shorts/-6nf6_zrNxY?feature=share[/youtube]

Karbonius plenum without reinforcing:
[youtube]https://youtube.com/shorts/NtCRPz1705A?feature=share[/youtube]

 

[Hydro_Z4]

A quick question regarding payment.
I'm assuming each buyer will be invoiced and pay directly from Karbonius?

If so, is it possible to be invoiced ex-VAT if the buyer is a company within the EU?

 

[///MBan]

A quick question regarding payment.
I'm assuming each buyer will be invoiced and pay directly from Karbonius?

If so, is it possible to be invoiced ex-VAT if the buyer is a company within the EU?

I haven't been given the payment process yet, but I will ask for it when I get back to them on Monday with the number of people that have indicated they will buy a plenum. The payments will definitely all go directly through Karbonius, though - I don't want anything to do with that!

I'm not really sure how VAT works for you guys, so I couldn't say. I'd imagine it would be the same as for their other products?

 

[Hydro_Z4]

Please add me to the list

 

[///MBan]

Please add me to the list

Will do - thanks