Your car senses air volume using a "HFM" - Hot Film Meter. This is a delicate piece of material, thinner than paper. Electrical current is run through it so it heats up, and the car determines the volume of air (automatically accounting for temperature) via the change in resistance (due to change in temperature) of the wire.
So with this extremely delicate, sensitive, and expensive part in your intake tract, you should strongly take the advice that the air filter is a critical piece of protection that should not be left out.
In case I was too long-winded (as usual), I'll sum it up: put the air filter back in as soon as possible!
" In the vast majority of cases increased airflow will increase engine performance measured by horsepower and throttle response (torque). The performance benefits of maximum airflow are clear, compelling and well documented. That is why so many professional racers are willing to run expensive vehicles with no air filter, as opposed to installing a disposable air filter. They are seeking the additional horsepower and throttle response needed to win the race."
i got this from K&N website. i was wondering how did those race cars run without one. do they just replace a new engine after each race?
I know and race w/ lots of guys that remove their filters to race, not w/ bimmers though. No real damage yet. And before anyone gets butt hurt and flames, I'm not talking about streetracing, I mean autox and track days.
When I dynoed my 330 the car actually lost whp/tq (about 7hp/tq to the wheels) by removing the air box.
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