holdup

have a noise when boosting that sounds like uneven air its seems to flutter through the turbo rather than a smooth whoosh . only slight . is this normal and is it the resonator box that causes this noise .

MarkFitz

have you modded the intake and exhaust?

holdup

yes full de cat and green panal filter ?

holdup

can no one answer this question , thought it was fairly simple

prana

if you mean the resonator at the intake, it shouldnt be the source of the noise.

harvey

iTrader: (48)

It might be a simple question but identifying a noise by e-mail description is actually not easy as we all hear/read different things.
Has the noise started since you replaced the pannel filter?
Ensure the air box cover is on properly.
Has the noise just appeared or always been there.?

nickyrhodes

Sounds like mine does i think, it started after the full decat, been running it for 4 years

Northern Nick

iTrader: (1)

Sorry to bring this old post back up but mine does it to.

If you read the "Engine Stage 2" thread on this site, he describes it as having your lips just slightly open then sucking in, now wave your tongue up and down past the opening.

Thats the sound

Its because the turbo is producing more air than the engine requires, dont ask me how this happens, its just what I've read. The noise you hear is air being forced back towards the turbo from the inlet against more air going from the turbo to the inlet, kinda struggling to pass each other in oposite directions.

Does that make sence? I think it does

It is possible to map out on curtain ecu's

Its to do with to much of a free flowing thing

Casey

Isn't that why you have blow off valves to release the air pressure and not having it backflowing after the throttle body closes?

Northern Nick

iTrader: (1)

Its not when you back off, its while your still on boost.

Thats what I cant understand either , but I read it here

Northern Nick

iTrader: (1)

I've found it

The surge appeared between approximately 3000-4000 rpm and from 4000 rpm onwards it disappeared. This was both extremely audiable from both inside and outside the car, which sounded very similar to you trying to breath in through your mouth nearly closed and then quickly moving your tongue backwards and forwards from the opening (sounds weird, but gives the same audio effect). While looking at the boost gauge as the car was being run on the rolling road, it showed the boost very rapidly fluctuating around the boost target through this same rev range and then settling from approximately 4000 rpm onwards.

It was stage 1

Link: https://www.scoobynet.com/scoobynet-...ge-1-a-17.html