highonline

Got your e-mail gramma, sorry for not replying sooner, been busy these days!!

The reason you might get a whisle is if your fan sucks more air volume than what the pipe can permit, you will get a hum. just like when you put your hand on the end of a vaccum cleaner pipe, the motor whines and you get a higher pitch ( or more noise ) because the motor encounters some resistance making it work harder.

This is not an exact analogy but your get the idea!

You could have a 2 inch fan on a 4 inch pipe with no problem but try running a 2 inch pipe on a 4 inch fan and you'll understand. If you fan is mounted directly on the inlet/outlet and you do not have any piping involved then you are fine unless you have like a million cfm ( cubic foot per minute ) fan!

To answer you question, yes, you can run a fan on your exhause withour having one on the intake, no prob!

highonline.