K&N Filter Cleaning
09-14-2006, 12:03 PM
#31
Rennlist Member
Originally Posted by SimonExtreme
Not wanting to start a war but, to take this forward.................
A dirty filter is inefficent and shouldn't be on a car, period. Therefore, we only need to consider filters correctly fitted and in decent condition.
Looking at the airflow rate, if a filter is capable of flowing the required amount of air, then its ability to flow more is "wasted". And that, IMO, is all that we need to be concerned with. The engine cannot turn excess capability into power!
So, what needs to be looked at is real evidence that changing filters makes a difference. We know, from tests, that altering the airbox doesn't increase power but I am not sure that I recall having seen tests comparing standard filters and K&N, for instance. I do know that the K&N flows enough for a standard engine and this is what my car came with. My car also has throttle body mods and I suspect that this has a bigger impact than the filter.
A dirty filter is inefficent and shouldn't be on a car, period. Therefore, we only need to consider filters correctly fitted and in decent condition.
Looking at the airflow rate, if a filter is capable of flowing the required amount of air, then its ability to flow more is "wasted". And that, IMO, is all that we need to be concerned with. The engine cannot turn excess capability into power!
So, what needs to be looked at is real evidence that changing filters makes a difference. We know, from tests, that altering the airbox doesn't increase power but I am not sure that I recall having seen tests comparing standard filters and K&N, for instance. I do know that the K&N flows enough for a standard engine and this is what my car came with. My car also has throttle body mods and I suspect that this has a bigger impact than the filter.
Agreed all your points. All NA engines have a finite ability to draw a maximum amount of air based on many factors related to engine design and components. I think other filter solutions allow the proper amount of air into the engine. From what I have read it appears the quality of the air flow is as much important as the quantity of air. Thats where the OE Porsche airbox design may actually be better. A larger flatter filter surface area allows a greater Laminar (straight) flow of air vs. cone filters which tend to produce turbulent air flow.
The use of an OE filter or K&N filter in the OE airbox should not matter in regards to the quality of airflow as you are maintaining the larger flatter filter area. Other posts have suggested the "wetting" of these filters may in fact be doing harm based on oil analysis. Lots of things to consider.
My car came with a K&N cone design filter. Im looking for an OE airbox (PO tossed the airbox) to revert back just to satisfy my own curiosity.
