they were in the turbo intake tubes. they seem to me like restricters but I don’t know.

 

Silencer for the airpump. Without it and with an aftermarket intake it sounds like a dying goose.

 

yeah I remember one of our Australian members once referred the noise as a drunk kangaroo who was on their last leg.

 

Thats pretty funny.

 

Is that a stock part or add-on / hack?

 

It's from Knight Sports, I think a few other Japanese tuners did something like that. It's similar to the chair cap mod I figured out a zillion years ago, that's actually where I got the idea.

If you can restrict the airflow out of the waste air pump air that comes from the air control valve you can shut up the "moo". Those just get pushed in the hose. They want good money for what is just some aluminum bar stock cut to length with 3 holes drilled in it.

Dale

 

Similar restrictors come with the Autoexe carbon intakes as well.

 

I would think restricting blow off isn't a great idea. Better to plumb back into the intake (e.g. stock) if you don't like the whooshing sound

Edit. Nevermind.. Thought they were in the blow off, not the air pump. Same concept though. Restricting airflow????

 

Yep, it's just to muffle the air pump "moo". You only need it on the outlet/dump side of the air pump system.

I ran a setup like that for a long time, no ill effects. It's the best way to quiet it down with something relatively small, you don't need a big muffler or something. The stock air box has kind of a muffler built in to it for that hose FYI.

Dale