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CSL Airbox

J

Justino

Member
So...I've long hankered after fitting one - or a replica at least, and having removed the oe airbox to get at the broken starter motor, I am wondering if now is the time, rather than refit the oe back after I get the starter motor.

Having got this far, I am assuming its relatively straightforward fitting, CSL dip stick tube needed, but are there any other pitfalls I need to be aware of.

I was leaning towards the Geoff Steel box - do these need modding for the Z4 as designed for the M3??

Help me make the right decision....

Cheers
 
Hi,got Geoff Steel air box on mine,dipstick tube was modified to suit.
Only change on mine was the inlet rubbers on throttle bodies on mine had to be changed due to larger diameter on later s54.
Areeve performance in kings Lynn fitted and mapped to Alpha N.
 
as jon said it will need to be de Maffing and re map for the additional air and changes.

and then never listen to music or radio ever again ;-)
 
I think you can either bend or swivel the existing dipstick tube so it can still be accessed without removing the pre-filter part of the box. The csl had a digital oil level display I believe so manual checking wasn’t deemed as critical.
 
Get it done..............! :thumbsup:

Love my CSL airbox - the noise is worth every penny. You will need a re-map, different inlet rubbers and some wiring changes to go from MAF to air temp sensor but that's easy stuff. The dipstick can be swiveled around as Beanie details above. Some good threads on here for guidance. 8)
 
not sure where you are based but BMR in dartford are a great indy

fitted my airbag plus done the de MAF and re map.

they build a lot of race cars with the big airbag and fast road cars too.

I love mine and the noise is addictive.
 
Thanks, I was considering a DIY job seen as I have the existing airbox off to fit the new starter motor.

I'm aware it needs mapping, I was thinking it would be fine to fit and drive to a mappers as it defaults to a standard map if it doesn't get a reading from the MAF

Seems I need to do some more research on what happens to the MAF wiring, and the throttle body rubbers.
 
On the MAF delete and wiring, I have found this to attach the new IAT to the MAF wiring without cutting anything
https://www.turnermotorsport.com/p-597496-alpha-n-iat-sensor-relocation-kit/

Also available on ebay in the UK - anyone have any experience of these?
https://www.ebay.co.uk/itm/265737988222

Can spin dip stick through 180 degrees apparently, and about 5 cm needs trimming from the snorkel.

Also CSL intake rubbers needed and clips - 3 and 4
https://www.realoem.com/bmw/enUS/showparts?id=BL96-EUR-12-2003-E46-BMW-M3_CSL&diagId=11_3517

Maybe some cable brackets required, but thats minor stuff.

Getting closer to pressing the button.
 
The wiring is pretty simple for the MAF - you are deleting all the wires except the ones in the MAF that measure air temperature, so an adapter such as the Turner one is a good thing to get if you are thinking of going back to standard. What is important is the temperature sensor itself - I used an OEM E46 CSL item. If you do a search on here, you should be able to find the part number.

I turned my dipstick towards the rear of the engine bay and made a bracket to support the dipstick to the engine - no trimming required! :thumbsup:

Those look like the right rubbers and clips - investing in a set of pliers to undo and tighten the clips is a good small investment of about £15 if I recall...

It's an easy DIY job honestly to fit the box - get that button pressed!! 8)
 
Loads of guys on cutters have used the plug and play IAT loom from eBay, it’s a nice solution.

The IAT sensor type depends on the box you buy. The GSR box takes the screw type sensor, Karbonious takes the push fit CSL sensor.

The scaling for the later is different so needs to be adjusted by your tuner.

Trimming the snorkel is fine, it’s not idea though which is why I designed and 3d printed my own. :thumbsup:
 
Shutoff valve can be reused you just need to replace the hardline with some silicone vac hose.
 
Depending on which box you get, try and put the iat sensor as far away from the engine as possible. Look for the coolest spot in the airflow.
 
Martyn said:
Shutoff valve can be reused you just need to replace the hardline with some silicone vac hose.
Click to expand...
I have the CSL one ready.

Still prevaricating - have now got the starter motor fitted, so I am on the reassemble stage.

One box I haven't considered is the Goke one https://www.catune.co.uk/single_pro...dHlwZT16NG0mY2F0X2lkPTEmY29tcF9pZD0xNzc=.html

I like the idea of this as it connects to the air ducting so you don't get any hot air from the engine bay leaking in. My doubt on this are it doesn't look 100% oem, which is one of my goals, and there is a suggestion (Vanne maybe) that the standard Z4m ducting wouldn't deliver enough air compared to the M3 CSL ducting size. This I guess could be countered by an RPI Ram inlet.

On a genuine CSL car I assume it is only the snorkel that is connected to the air ducting, but the main air intake (where the flaps would be) is open to the engine bay. As the flaps open up above 3k rpm, it suggests that BMW were happy for it to work this way above 3k, so maybe an open snorkel, RPI ram intake and ducting directing the air up to the opening would be nearly equivalent?

If I go down the OE look, then its Geoff Steel or Karbonius. obviously GSR is cheaper, but its wet laid carbon as opposed to pre preg and autoclaved.

I'm not so keen on cutting the snorkel to make it fit, as it leaves an unfinished bottom edge, and its obvious it is missing the radius.
 
Regarding the Goke airbox, I wouldn’t worry about intake sizes. I think that’s the box TomK on here has fitted and, iirc, his car has put out very respectable numbers and spends a lot of time on track.

Personally, I think the rpi scoop is a bit of a gimmick and I doubt it will do anything. However, there was a guy on here who made his own ‘scoop’ then had a few made and sold them. It was a while ago but I remember it looking good and other than a potentially soggy filter, is probably as good as any kind of scoop gets. There’s a thread on here somewhere showing his progress, can’t remember who it was though.
 
beanie said:
Regarding the Goke airbox, I wouldn’t worry about intake sizes.
Click to expand...

The issue I have with this is that the standard Z4m airbox/filter housing has just the one air input that i can work out from the intake pipe that goes to behind the grille.

The CSL has the snorkel input routed to the bumper I assume, and also an input underneath the airbox, but not sure where this is routed too. In addition you also have the open mouth of the top section of the snorkel piece which on the CSL has the flaps in - so all in all a larger cross section of air input openings, 2 of which might be ram air.

The increased BHP of the CSL no doubt is down to the greater air input, so I am loathed to invest in a CSL intake, and then restrict it by just using the standard Z4M piping - the Goke box appears to me that it wouldn't give any extra air as its a sealed route to the existing input piping, therefore same air volume as a standard intake.

I am thinking that the air input underneath the CSL box, I connect if possible to the standard Z4M air pipe, and then somehow route airflow to the mouth of the box from another location, maybe lower grille area?

Be interested to get opinions?
 
CSL had the different cams with a higher profile and a different map I think so combined with the additional air coming in through the giant intake that would add up to the small gains. and 200 cell cats from OEM so that will help with breathing.
 
If, and it’s definitely an ‘if’, there is a restriction in the inlet, then it’ll be the MAF housing. Obviously all airboxes do away with this so you’ll reduce restriction whichever you choose. There’s no doubt bmw will have researched and engineered things properly, far better than any aftermarket company, however, unless you’re pushing the envelope in terms of power then I truly believe all the mafless airboxes will be pretty much identical in the real world.

As NLW73 said, the csl had different cams and also larger exhaust valves. Still, the Goke still seems to allow for gains with more aggressive cams so whilst the theory of restriction seems sound on paper, it appears it’s no issue even with a decently tuned S54.

I’m not trying to push you in any direction but just putting it out there that you’re unlikely to run in to an issue with the Goke. FWIW, if I was buying an airbox today, I’d probably go with a karbonius simply because it looks most like the original. If the budget was a bit tighter I’d have no issue fitting a GSR box.

Whichever you go for, the added horsepower will pail into insignificance compared to the sound they all produce. 10,20hp isn’t life changing but the induction noise really is! :D
 
My two cents having opted for the Goke version.
Personally I don't think that the diameter of the air intake is as important as the speed and temperature of the air reaching the trumpets. In this regard the idea of taking the air directly from the front of the car is superior in my eyes to that of taking air in from the engine bay.
The RAM air affect that the CSL uses (and I assume the z4 (I also have an RPI sccop)) is quite important to the workings of it. As the car picks up speed, air with higher velocity enters the ram air intake in the front bumper which is sent to the intake.
The air is colder and with speed (instead of the typical NA engine behaviour of having to suck air, you send air with pressure).
More air, colder air + Alpha-N = more HP.
I also think the original CSL ducting design is slightly compromised, not surprising when they had to repackage the front end. A lot of E46 M3 race cars take air in from a modified headlight ducting straight to the mouth of the CSL box.
When I had my car mapped and dynoed, my friend had his m3 with CSL box also mapped there the next day, so same dyno/operator/atmospheric conditions. Mine had 288/80 cams and made 384bhp, his with standard cams made 353. I don't care about the absolute numbers but cams do not give 30bhp and whilst there are of course lots of other variables I think it is safe to say that the size of the original Z4 intake hole is not a restriction worth noting imo.
As Beanie says, whichever route you go it's really just the noise that's important!
 
Thanks for the input guys.

I am leaning towards the Karbonius for the reason you suggest - looks more OE, just need to decide which finish to have 2x2 Twill, or plain, then matt or gloss. I know its not OE, but like the idea of the matt finish, but not sure which weave is most OE.

I get what you say about the air, but as I haven't pulled the trigger yet, I just wanted to consider all the options, and now is the best time to try and figure it out.

My logic is the E46 has 2 ducts to the air box, underside (ram air?) and to the snorkel, plus the open end when the flap open with some ducting by the slam panel that directs air to that location, so that's quite a bit more than the Z4, which just has the one ram air.

With my idea of routeing the standard grille air intake to the under side of the air box opening (ram air?), and try for some ducting to the front opening to direct air in the right direction (obviously no snorkel), then that should be as close as to the E46 CSL as possible.
 
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