Karbonius Airbox vs OEM CSL Comparison - Picture intensive

[NZ_M3]

So I purchased the airbox from MS Motorsport and thought I'd do a quick write up about this as a comparison with OEM item.

As many will know this is the latest generation of the Karbonius airbox - I have always been fascinated with how good these are and decided to get one (part of my airbox collection for the S54). This latest generation is supposedly 3D scanned from the OEM CSL airbox (its FB page shows the process) - the airbox is then modified by Karbonius on various areas to make it I suppose "better" than the original.

This latest box is also pre-preg carbon like all their previous airbox, but it is now also autoclaved.

The finish is superb and comparable to the OEM in both thickness (OEM carbon is roughly 1mm thick in most of its areas, whereas the Karbonius is around about 1.2 - 1.3mm. No surprise however that the Karbonius airbox is lighter as it uses carbon trumpets. The OEM plastic trumpets are actually quite heavy.

Anyways, on with photos:

The airbox

Internals


Next to the OEM CSL airbox - Dimension wise they are virtually identical. One thing to note, the Karbonius seems a little bit more angular in areas where the OEM seems a little more curvaceous. I think the edges are a little more pronounces and sharper on the Karbonius when compared.






Main filtered box comparison (the placement of the BMW M Power lettering is a little bit off compared to the OEM and the "e" font is a little different. Overall the lettering is skinnier compared to the OEM and the spacing a little out)







The trumpets - This part is slightly different to OEM. The Trumpet angles are slightly off compare to OEM - Cylinders 5 and 6 on the OEM box is angled towards the opening of the box, and cylinder 6 sits abouts 4mm further back than all the other trumpets. The runner angle into the ITBs also seems to be slightly different on the Karbonius, it is a narrower angle. I have yet to measure the runner length, but from eyeballing the Karbonius seems ever so slightly shorter and is spaced slightly wider apart as a result being shorter (see photos)






Here you can see the runner are angled differently between the two airbox and should be able to just make out that cylinder 6 sits shorter compared to the others and 5 and 6 are angled towards the opening.



inlet angle slightly narrower on the Karbonius (sorry hard to pick this up in the photos, but next to each other it is quite obvious)



Top view (you can see where the Karbonius modified the mounts here compared to OEM - they did this I believe to make the two sections a tighter fit - which they have no doubt achieved with the sharper edges and prominent cutout:



Bottom view comparison



Twill Comparison (the CSL has slightly wider twill and appears to be a heavier weight fabric compared to the Karbonius)


IAT bung - I find this detail a little annoying myself as it is rotated 180degrees on the Karbonius - the fit of the sensor also seems a little loose to me and not as tight as OEM Personally I think a larger sensor seal might work better with this bung.



The hose hook seems a little lower on the Karbonius also:



Unfiltered section: The new Karbonius flapper flange mount is now aluminium just like the OEM version.



These two parts weigh almost exactly the same - but the finish inside is a little different. The best way I can describe it is it is as if the OEM carbon had a better vacuum machine drawing out the air, so the carbon cloth was compacted better and flatter - the karbonius weaves are quite prominent on the inside when compared with the OEM.






You can see here the weaves are lot more prominent on the inside finish of the Karbonius (the vacuum compactness I referred to above)



And here's how Karbonius modified their box for that tighter fit:



Improvements - these are very minor issues, but ones that I believe would greatly improve this airbox

Filter fitment - when using the OEM filter, the fitment isn't as tight




I also found the stock filter was just a little too thick for this airbox and needed a tiny bit of trimming on the red silicon in order to make the unfiltered section fit on. I believe the ITG filter will probably fit a bit better and without the issues of the stock filter (in the process of acquiring one)


The trumpet outlet also has a very slight overlap with the rubber boot which you don't see on the OEM airbox






To be honest I am nit picking on the Karbonius and I would be more than happy to run this on a genuine CSL as an alternative. The finish is phenomenal and very comparable to the OEM unit. All the aluminium fittings are top class and almost identical to OEM. There are some very fine minor issues, but it's really neither here nor there when you factor in the value of the airbox - It truly is a bargain when you consider for the price of an OEM unfiltered section, you can buy a full airbox from Karbonius.

I would personally rate this airbox 9/10 easily.

p.s. I shall do a review of the Geoff Steel airbox with the Karbonius soon and also the P54 airbox.

[LeinsCSL]

Thanks for posting, interesting stuff. Excuse my ignorance, but was does "autoclaving" mean?

[mattCSLnut]

Superb review Tom THANX for sharing

[alexk]

Very nice Tom, thank you !

P54 airbox ???
Where how etc ???

[Roland]

thanks for sharing

[Mark CSL]

Originally Posted by LeinsCSL

Thanks for posting, interesting stuff. Excuse my ignorance, but was does "autoclaving" mean?

Its a pressure oven the carbon is under pressure This is what you need to make prepreg carbon parts correctly. not getting to tecnical

[LeinsCSL]

Originally Posted by Mark CSL

Its a pressure oven the carbon is under pressure This is what you need to make prepreg carbon parts correctly. not getting to tecnical

Aha, thanks Mark

[sailorbaz]

Excellent post and thank you for taking the time to give us an comparison.

[cslsuperfan]

Superb Thread Tom.

Thread searched your bumper removal post from a while back.

Also very informative.

[NZ_M3]

Weight Update
So I weighed both airboxes to get an accurate weight with a kitchen scale and I was right, the Karbonius is lighter overall
Karbonius main filtered section weight - 1542g (no IAT sensor)

CSL OEM main filtered section weight - 2073g (no IAT sensor)

Karbonius unfiltered section weight - 393g

CSL OEM unfiltered section weight - 483g

Turns out also that the trumpets are the same length. I guess it is the end flaring that's different thus making it seem shorter.
Trumpet weight - OEM - 118g