In answer to Trigger, he attached the INTAKE end of the leaf-blower to the airbox assembly, so this is the end that sucks as the other end blows. In the later pics the blower (suction end) is attached to AFM side of air-box, so it is quite clearly sucking air through the airbox as the engine would do.
After reading previous comments regarding how well the original BMW airbox flowed I removed my K+N cone-filter and replaced all of the bits for the BMW airbox including the cold air intake next to headlight. I disconnected the battery to reset ECU, and ran the engine at idle for 10 minutes for it to relearn settings before taking it for a drive. Once the ECU had learned the rest of the settings the engine felt it had more go than it did before when it reached 4000rpm. I can only compare it to how it was with K+N and it is better than K+N.
At the time I fitted the K+N I also chipped the ECU, (I used a Digitech chip I bought off e-Bay before I knew about Zone chips) so as the chip improved the flatness below 2500rpm I thought I was on a winner. With the chip the engine would pull cleanly from 1000rpm in 5th gear which it would not do before, with much improved drivability in the other gears. The only thing I will miss about the K+N is the noise it made.
So I was one of the suckers who believed the hype about cone-filters. Maybe I'll put it on e-Bay or do any of you guys want it?
E30 air filter tests
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