OK, I know intakes (at least in regard to the 1.9L m44) have been beat to death but I'm exploring doing something to mine so I was under the hood just having a poke around. Why is the intake path (shown in green) so convoluted when it could be a straight shot (shown in red). The gap is already there, I can stick my hand through it and everything! I'm thinking about designing a custom intake and modifying the airbox to take advantage of this more straightforward path plus increasing the diameter of the hose as long as I'm in there.
'97 M44 Intake Path
- Thread starter greisinb
- Start date
My 98 2.8 follows the red path. Maybe you could try a 6cyl airbox, it might mean fewer modifications
Interesting, it certainly would be nice if the part basically already exists, even if it’s just the actual intake itself, modifying the air box itself is pretty straightforward.
The intake path on my 2.8i is the red path. It has a little plastic duct which channels air into this area. I’m sure you could pick one of these up for very cheap and pop it in. From memory it also connects to the airbox.
Additionally, there are a few aftermarket 3D printed ducts that replace the near side fog light that could provide additional airflow.
There is debate on stock cooling vs aftermarket with forum members like @Pingu conducting their own experiments on airflow, finding the stock airbox to be very effective, iirc.
From what I’ve read, heat soak is the drawback. Lots of cone filters added to the engine bay but without any shroud or engine bay compartmentalisation to stop warm air from the engine heat entering the cone filters.
BDS motorsport have tuned the M44 extensively and his air intake is a simple cone filter but the custom ducting before the MAF sensor sits low with quite a long metal tube. The cone filter is way down and away from the engine to ensure it’s cold air that’s being drawn in and not heat.
Aside from wooshy sounds, the HP gain from the BDS intake, with a tune, is around 5-10hp. It’s not huge.
Additionally, there are a few aftermarket 3D printed ducts that replace the near side fog light that could provide additional airflow.
There is debate on stock cooling vs aftermarket with forum members like @Pingu conducting their own experiments on airflow, finding the stock airbox to be very effective, iirc.
From what I’ve read, heat soak is the drawback. Lots of cone filters added to the engine bay but without any shroud or engine bay compartmentalisation to stop warm air from the engine heat entering the cone filters.
BDS motorsport have tuned the M44 extensively and his air intake is a simple cone filter but the custom ducting before the MAF sensor sits low with quite a long metal tube. The cone filter is way down and away from the engine to ensure it’s cold air that’s being drawn in and not heat.
Aside from wooshy sounds, the HP gain from the BDS intake, with a tune, is around 5-10hp. It’s not huge.
- Joined
- Dec 8, 2011
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- 165
The 6-cyl airbox mod would be a good mod, and is what I would do.
Two reasons...
More direct airflow
Air is not heated by the radiator
While you have the airbox out, I'd wrap it in gold insulation tape, as this would keep the air inside the box cool. BMWs have self-learning ECUs, so you don't have to worry about air being too much, and there is no fear of running lean - unless you get really silly airflow and start to exceed the fuel injectors' capacity (which won't be a problem with this mod).
I'd go for it
I went full on mental with my intake system
...
zroadster.org
zroadster.org
Two reasons...
More direct airflow
Air is not heated by the radiator
While you have the airbox out, I'd wrap it in gold insulation tape, as this would keep the air inside the box cool. BMWs have self-learning ECUs, so you don't have to worry about air being too much, and there is no fear of running lean - unless you get really silly airflow and start to exceed the fuel injectors' capacity (which won't be a problem with this mod).
I'd go for it
I went full on mental with my intake system
...
Pingu's M Roadster
http://www.ebcbrakeshop.co.uk/info-part-list?make=BMW&model=Z3&spec=3.2 M&year=1998 (R-S) now discs and pads are £298 Ultimax and Redstuff are different ;)
zroadster.org
Pingu's M Roadster
http://www.ebcbrakeshop.co.uk/info-part-list?make=BMW&model=Z3&spec=3.2 M&year=1998 (R-S) now discs and pads are £298 Ultimax and Redstuff are different ;)
zroadster.org
Are you/do you propose swapping out the entire airbox assembly (as opposed to just the intake tube) from a 6 cylinder model? Do you know if it’s the same airbox used in a E36 325/328?The 6-cyl airbox mod would be a good mod, and is what I would do.
Two reasons...
More direct airflow
Air is not heated by the radiator
While you have the airbox out, I'd wrap it in gold insulation tape, as this would keep the air inside the box cool. BMWs have self-learning ECUs, so you don't have to worry about air being too much, and there is no fear of running lean - unless you get really silly airflow and start to exceed the fuel injectors' capacity (which won't be a problem with this mod).
I'd go for it
I went full on mental with my intake system
Pingu's M Roadster
http://www.ebcbrakeshop.co.uk/info-part-list?make=BMW&model=Z3&spec=3.2 M&year=1998 (R-S) now discs and pads are £298 Ultimax and Redstuff are different ;)Pingu's M Roadster
http://www.ebcbrakeshop.co.uk/info-part-list?make=BMW&model=Z3&spec=3.2 M&year=1998 (R-S) now discs and pads are £298 Ultimax and Redstuff are different ;)
bmwz3tower
Dedicated Member
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- Dec 5, 2024
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- 29
Will the M54 airbox fit the studs for the m44 airbox?
I don’t think the 6cylinder airbox will work on an M44 engine as the MAF, throttle body and intake hoses are totally different angles.
It would require some mods to make it work, flexi ducting at the very least.
I would start with the OEM 6 cylinder air duct that would usually channel air int the airbox. It might be something that will be able to be connected to the OEM M44 airbox , perhaps with some cutting or modifying to direct it into the airbox.
GL
It would require some mods to make it work, flexi ducting at the very least.
I would start with the OEM 6 cylinder air duct that would usually channel air int the airbox. It might be something that will be able to be connected to the OEM M44 airbox , perhaps with some cutting or modifying to direct it into the airbox.
GL
- Joined
- Dec 8, 2011
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- 165
I have no experience on your engine or "normal" 6-cyl engines, but modifying standard parts is much easier than making stuff from scratch.
Even if I were to modify a 1.9 airbox, I would modify a spare one, as you can always put the original one back on if you decide you don't like it, or it doesn't work.
Thanks for all of your replies, sorry it’s been a few days. I’m going to document this in another thread once I get around to it but my plan for right now is to use the “suction hose” off of a 2.8, 3D print a custom adapter and housing for a filter before connecting it all into the intake/MAF tube.
Trevor /chedder
Zorg Legend
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- Oct 23, 2021
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Check out "fogging the air box." It's in the resources section. I did this and got rid of the pipes and just cut a hole in the front of the box and placed the vent nozzle in there. I'll take a photo in the week.
Trevor /chedder
Zorg Legend
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- Points
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BMW Z3 A better air intake by Mike Fishwick
BMW Z3 A better air intake Article reproduced with the kind permission of Mike Fishwick I have a feeling that the original design of the Z3 air intake system was dictated more by the space available, rather than engineering considerations. For...
zroadster.org
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- Points
- 165
Further improvement. Create an air gap between whatever is reflecting the heat and the air box. This has two effects - reduces conductive heat transmission to almost zero and introduces convection cooling by dragging cold air from under the airbox trough the gap (negligible)
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Pingu's M Roadster
Well it's managed 60 miles so better than someone we know =)) shush now.....
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