After market air filter

[rick540]

Rick look at some Kawasaki motorbikes with Ram Effect where tubes below the headlight channel air to the airbox , this works well at high speed with higher bike speed causing higher air velocity and pressure , increasing the power .

I love these systems, they are very hard to design but when they work they almost defy physics. major respect to the engineers who get these right.

 

[Wick-ed]

Shame. Many hasn't fitted a CAI, but throw in their penny's worth. For those that did, well its their opnion.

 

[Sankekur]

My problem with a CAI is that is usually sits too low and I prefer to have my air intake higher up, I just feel safer to me.


And on the topic of e46 specific air filters, all the models 318i up to M3 of the e46 range use the same filter element so if it fine for the 250kW + beast of an engine in the M3 then I am sure it will be fine for your car.

 

[sclass]

:fencelook:

 

[moranor@axis]

the thing is the filter is not the restriction... its the air box... changing the filter does almost nothing... this is why im making a custom CAI with a larger paper filter...

i will have proper filtration and more airflow...

Dude, do you honestly think that the engineers who built your awesome to drive BMW and got it's 300000 parts to work together properly and give feel are stupid enough to then go and fit a restrictive airbox?

These things (Airboxes) are incredibly clever, and use resonance and air velocity and what would normally be wasted energy to physically pump air into the engine at certain RPM's.

The biggest myth here is a big hole or pipe = lots of air, that's a truly retarded way of understanding it. Using helmholtz resonance and an understanding of fluid dynamics you can shove a massive amount of high velocity air through a tiny hole faster than a standard large hole.


Argh.... I give up, just chop the factory air boxes up if you guys think it's a good idea.... whatever.

how then do these after market CAIs make more power?

I agree the engineers did a great job of making a quiet free flowing box but if they did not have the restriction of making it quiet they could do better...

 

[Raybimmer]

The info on the net does have a well designed CAI giving a bit more power , but I think moving the inlet to near the brake cooling ducts for instance is not practical for some of us ,I would not like water in the motor .
Maybe someone can do some dyno time to get answers , then we will be proved right or wrong .
Speed and sound magazine did some tests with various filters a few years ago maybe we need to read those tests for a bit of info as well .
My cone filter on my 325i sounds nice ,I dont know if it is better or worse than the standard filter .

 

[moranor@axis]

the intake for the long tube intakes is not as low as you think... it sits more or less at the top of the bumper...

thats one huge puddle...

 

[328-iM]

You can just as well take the filter out and drive like that when you put on these cone filters....don't have any migron rating what so ever.......