So what damage has occured to you N54 engine through using cotton gauge type filters?

pbondar

Corporal
May 30, 2020
150
49
0
By now there have been many filtration tests that show that compared to full flow paper filters in a proper airbox that almost all (if not all) gauge type filters (K+N etc) let a large amount of fine particulate matter through the filters.

The question is: how much damage is this extra injested particulate matter doing to the engine and which parts?

I assume piston rings would suffer?

I assume changing your oil more often to remove particulate matter may help?

Maybe the heat of combustion destroys /renders ineffective particulate matter?

Maybe those particles don't do any damage?

I'm very keen to to hand onto my stock airbox and full flow paper filters but wonder how much loss of go I'll suffer once I go above the current MHD stage 2+ at 400 bhp crank onto the the TTE500 turbos to be fitted in the winter?

A brief test of no filter /airbox lid showed we moved from 400 bhp to 407 bhp.

All this on an E89 35is..

Comments pls?
 

Asmo

Lurker
Aug 23, 2020
16
8
0
I had issues with collapsing inlets when using stock airbox on a friends car I was tuning.
 

NoGuru

Captain
Jan 9, 2018
1,177
556
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Just North of Detroit
Ride
BMW 335is
You need the extra airflow of the cones if you are going higher then 400or so HP.

I don't think you need to worry about filter particulates. I think you might get 190K miles instead of 200K as an example. Unless you are in a harsh environment like all dirt roads, then I would stick to stock airbox.
 
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iminhell1

Sergeant
Jun 17, 2018
416
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The key to filtration is pressure drop.
Try catching a 100mph baseball. Odds are you'll want a glove.
Slow that baseball down to a reasonable speed and you can bare hand it.
Filtration is no different. All that surface area is to slow the incoming air, or put another way to grab air from the largest area possible.
So even with cones, you try to fit the largest ones you can. Bigger will filter better.