Killing intake drone

VMacKenzie

VMacKenzie

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Joined
Dec 9, 2007
Messages
625
For whatever reason 24-valves have more intake noise than a 12V or common rail. Not sure if it's due to the location of the intake horn, firing characteristics or what. But now that I put in a larger turbo, S&B airbox and have a fairly quiet exhaust system the intake drone is quite annoying now. With the hood up and free revving it there's lots of intake rumble emanating through the air filter, especially around 1800 RPM or so. I'd like to kill it. Maybe I need to do some kind of X-pattern silencer like 3rd Gens have on the turbo inlet hose.

Ideas?
 
Just reset my overhead after getting my head resurfaced and the was no change in intake drone but really nothing to complain about in the first place.
 
This is definitely a new one for the forum. Maybe talk to Levi and see if he can make a blanket to put on it?
 
I did run the valves not long ago, went .008" & .017" though. No plans for a second turbo at least not now, pretty happy with how the current setup is performing.

When I get some time I'm going to do some experimenting and see what happens, will update this if I have any success.
 
what about incorporating part of a factory 3rd gen intake tube? they have a baffle and foam that would act as a resonator
 
swap the battery and air filter, like in the third gen. for a while my bhaf was closer to the battery because i didn't have the piping to put it where i wanted it after my turbo swap. way quieter up there.

remember the scotty intake? that worked like it did because of the space under the cowl, like a big echo chamber.
 
thebullet83 that's not a bad thought. . . maybe that move with the X-baffle turbo inlet tube might do the trick.

WUnderwood I had the same thought as you but the header seems tight and no leaks, the rumble/drone is definitely emanating from the airbox.
 
Back to the top, made progress with this issue! Turns out much of the drone is the acoustics of the S&B intake! For whatever reason its chamber shape and filter orientation turns it all into a sounding board and really amplifies the drone.

I tried doing an X-pattern with pieces of flat metal shoved into the main tube leading to the intake horn, but it had zero effect. I did all kinds of things trying to muffle the S&B intake with foam and so forth but didn't help. I pulled it out and put the BHAF back in and wallah, MUCH better. More turbo whistle and less drone. There is still some there, if I had the fabrication skills of some on here I'd build a short FTE style resonator and stick it in the intake, that would probably do it. And if I did that the resulting tornado effect should help MPG :p
 
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I was thinking that you could try to face the air filter forward. That always quiets things down a lot.
 
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