318iS Airfilter Comparions

This page is been created off the back of the following thread on the E30zone forum posted by cee - http://www.e30zone.net/modules.php?name=Forums&file=viewtopic&t=193536&highlight=dyno+graph

"As part of my college project I dyno tested three different filters. These being an OEM panel filter, A K&N Panel filter and a K&N Cone filter.

The car is a completely stock 1990 318iS and all filters were new to ensure the test was completely fair.

I will upload the full report when It's compiled but for now I will give you the results of my findings. Not sure about you but this really answered my age old question of if it's worth shelling out for performance filters or not.

We carried out 4 runs for each filter and found the following:

Please note that 8-10 bhp should be subtracted to allow for the fan used within the test

PLEASE NOTE: MY DATA IS NOT A 100% REPRESENTATIVE OF K&N FILTERS OR E30S AS A WHOLE. EVERY CAR AND EVERY FILTER IS DIFFERENT. MANY OTHER FACTORS EFFECT POWER/TORQUE SUCH ASS ENVIRONMENT, DYNO, TEMPERATURE ETC.

THESE FIGURES ARE FOR REFERENCE ONLY."

OEM Filter

K&N Panel Filter

K&N Cone Filter

And a comparison between the averages:

As you can see, there really isn't a lot in it. Put onto a graph for comparison it gave a fairly surprising reading for me.

Torque

Power

I'll let you make your own conclusions, but it's pretty clear, if you're worrying about 1-2 bhp and a few ft.lb's, that the OEM filter gave the best result throughout the whole RPM range (if you're willing to lose ~1 bhp peak).