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Air Intake

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I have a 1993 subaru Impreza and im lookin at the air cleaner and intake and I am wondering what are all the hoses for im pretty sure those lil growths are probably some sound muffling things but what about the others can somone show me a picture and have like arrows pointing to what the things are for :D

There are three hoses of similar diameter that feed the Positive Crankcase Ventilation system. One runs to a mixing stud and up to the PCV valve in the intake manifold plenum, on top of the engine.

This system draws fresh air through the engine to purge blowby gases from the crankcase. Blowby is the stuff that slips past the pistons. Minimal amounts.

 

The should be one hose of a larger diameter than those three, and this feeds the Idle Air Control valve. When you are not pressing the throttle pedal, the throttle valve is shut almost completely and the engine would stall if it weren't for the air the IAC valve lets in during idle.

 

The PCV hoses may be connected at one of the "lumps" in the intake, since they function best with slow moving air. The lumps are also there to keep things quiet - boring!

  • Author

thank you set right :D so would it be safe to cut off those "lumps" and seal them up?

You would have to replace the piping. Cutting and sealing will never give a smooth inner surface, and roughness will cause turbulence in the intake.

 

Your air filter box is resting behind the headlamp right?? This "old" design is much easier and better to modify. My 1992 Legacy was similar, and all I did was remove the "intake silencer" that lives inside the fender cavity and run a 60mm pipe from the air filter box into the fender. Mounted a velocity stack on the end of course, to reduce turbulence. This gave a wonderful growl on hard acceleration, and zero noise increase at cruise. I put a K&N drop-in element in the standard filter box.

 

This a shot from below, inside the fender:

 

http://www.geocities.com/vik2r/Sube/intake2.jpg

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