FMIC and D/V Noise

[oz *sti*]

Hi all,

Just finished fitting my FMIC today and took the car out for a short drive and I noticed that the d/v noise has changed from what was a pssh (normal bailey d/v noise, hope you know what I mean) but after fitting the FMIC it has changed to more of a chatter noise on lift off..... does this sound right???

Cheers,

Alan.

[RS Grant]

Yep, it sounds right... in so many ways. [H]

Cheers,

Grant

[oz *sti*]

Nice one Grant, you have put my mind at ease a little. [Y]

[fai17]

I love the chatter....

It's not usual m8

[ANDYJDMSTI]

Mine just coughs, splutters and f@rts!!!

Might have something to do with needing it re-mapped...............in for a long wait as Mr F is chockers.[]

[fai17]

Mine just coughs, splutters and f@rts!!!

Might have something to do with needing it re-mapped...............in for a long wait as Mr F is chockers.[]

I've heard m8!!!!

[ANDYJDMSTI]

Mine just coughs, splutters and f@rts!!!

Might have something to do with needing it re-mapped...............in for a long wait as Mr F is chockers.[]

I've heard m8!!!!

 

Such a bl00dy pain living up here at times with respect to the car, i may have to take a trip down south or get someone up.  Cannot be doing with a couple of weeks of how it is now.[]

[colin_ross]

The noise you're describing is not wastegate chatter as such and will not disappear when remapped either.

What is now happening is you have a much bigger intercooler and masses of pipework which is all under pressure when on boost. When you lift off the pressure tries to push it's way back out of the turbo as it is no longer cramming air into the system. The noise you describe is the air being forced the wrong way through the turbo and is called comprssor stall.  It's extremely common on cars with fmics and because nearly all fmic cars have induction kits it's nice and easy to hear it too.

[fai17]

The noise you're describing is not wastegate chatter as such and will not disappear when remapped either.

What is now happening is you have a much bigger intercooler and masses of pipework which is all under pressure when on boost. When you lift off the pressure tries to push it's way back out of the turbo as it is no longer cramming air into the system. The noise you describe is the air being forced the wrong way through the turbo and is called comprssor stall.  It's extremely common on cars with fmics and because nearly all fmic cars have induction kits it's nice and easy to hear it too.

Well described Colin[Y]