zvhrst

IS IT POSSIBLE GET MFI TO CHATTER????

Rs1

iTrader: (1)

Chatter?
I think i no what you mean.Basically chatter is the turbo stalling,so no turbo no chatter im affraid.
Has names such as chatter,turbo stall,wastegate flutter.Am i on the right track?

Moonie

Chatter is caused by air returning through the turbine blades when the throttle is closed. This air is going backwards so will stall/slow down the turbo as it passes through creating a chattering noise. The MFI system dampens this noise as the air flow sensor plate in the metering unit closes because the throttle is closed and the ammount air the engine requires is reduced.

A EFI system has no sensor plate so the chattering can be heard directly through the air filter.

I am running MFI and i get some ammount of chatter, if you are using a dump valve this will reduce the ammount of chatter as its designed to bleed off the excess air so it doesnt return through the turbo.

Rs1

iTrader: (1)

Yep exactly,ive had both rst's(efi and mfi)chattering.

rst230bhp

iTrader: (1)

i get chatter running 17psi on mfi with a cone filter

sounds cool much better than a dump valve.

zvhrst

so if a just take my dump v off then a shud get a chatter, am runnin 21psi

Moonie

Wont do any harm to try

AKRS1

i was running 18psi with no chatter at all

DmcL

umm isnt chatter a bad thing for turbo life

AKRS1

it probably is a bad thing for the turbo but driving with a dump valve is crap. I use my car on a everyday basis and when doing around 70mph and lifting of the throttle the whole car jerks to 1 side with the dump valve taken off it drives perfect.

Rs1

iTrader: (1)

Aye turbo stalling is bad,not so much to worry about on low boost applications but it can result in the impeller breaking up and/or the turbo shaft snapping. If you have a decent turbo you wouldnt off thought you'd want that to happen. Not to mention any small metal parts be swallowed by the engine.

zvhrst

so why do all big power cars chatter??? if its bad, surley they wunt want it to happen wen u gone and spent loads of money on engine

DmcL

in some big power cases chatter cant be stopped completely but it can always be reduced by fitting a dumpvalve, blow off valve/pipe or wastegate. it doesnt cure the problem but any pressure lost from the dv/bov/wastegate is that much less pressure on the turbine.

and i havent even had a turbo car yet

rs shawn

do a search mate. There's loads of threads on whether chatter is harmful on the turbo or not.

MFI chatter: I've got it on the S1, but not on the S2. Both running same boost. They say if the MFI chatters, then the air sensor plate spring is weak: hence why it chatters. I think that the plate doesn't shut quick enough to stop the air escaping, but only stays open for a short time & this is why you get a bit of chatter, but not as much as with the EFI cars.