Webinar - Air intake restrictions explained

Hi there

I asked this on the latest webinar but probably wasn't clear enough... A bit hard to explain without pics and a diagram :).

Thanks for trying to understand it LOL

Hopefully these pics and diagram (Air-Cleaner.jpg)help (obviously some of the example pics of air cleaners "out in the wind" are carburated, but hopefully they get the point across)

Just wondering how airflow THROUGH the side of a filter, or front to back of a filter at Medium or high speed can affect the intake tract. (Largely NA question)

Obviously at over 100mph a hood scoop or similar can build some positive pressure in the intact tract, but below this speed can air passing right through the filter and not into the engine, still have a detrimental or siphon effect ?

We still see lots of air cleaners open to elements in all forms of racing with no shrouding to the rear or sealed scoop base.

In a (apologies up front) Carburated engine, it could make a big difference to booster signal etc with air flowing through the filter across the top of the carb or throttle body, and out the back of the filter, but in a TB equipped injected engine with either MAF or MAp, is it as critical, or with say ITB, exposed to open air also.

ie I guess in general terms, how much of an effect can the "condition"of the air going though a filter have on performance ?

Thanks in advance :)

From what I've read, the filters may aid power as it will slow down the air across the venturi openings and so reducing the suction affect. Depending on the air dememands of the engine, even at the back of the filter there may be airflow into the filter.

Back in the day, there was a fair bit of 'discussion' with the open stacks on some of the old CAN-AM cars and the dynamic airflow across them - I don't recall what the final call was, though.

As I'm paranoid about foreign objects getting into the engine, I'd be inclined to run some sort of filter regardless - at the very minimum, a mesh screen.