ross_wrx

Hi guys and gals!

Just a question about something that has been bugging me for a while...

I have a 2001 Turbo 2000 with the following engine mods:-
Full Decat Exhaust
Forge VTA Dump Valve

When changing gear at low revs < 3000rpm I seem to get some turbo stall or chatter as it is sometimes known.

Is this normal with the above mods? Or should I get it checked out? It is due a minor service in 3500 miles.

Thanks

The rookie

iTrader: (1)

Compressor surge, sometimes called wastegate chatter or compressor stall (its actually cyclical stalling and unstalling that makes the 'ch ch ch ch' noise).

Sounds like the dump valve isn't opening, as that is what it is there specifically to prevent! Check the vac pipe and that the piston isn't seized as a starter.

Its not good for the turbo, although the MHI TD's seem to cope fairly well.

Simon

Coc-ker

iTrader: (1)

If you're only getting maybe 0.1 bar of boost by the time you lift off, the valve might not open fully and you still get a little chatter.

I get this on mine aswell.

ross_wrx

Not getting a lot of boost when I lift off so sounds the same as you. The valve opens fine when the revs are above 3000rpm or the boost is high.

eggy790

iTrader: (20)

is there a bov you can get that makes this sound all the time? sounds so much better

New_scooby_04

iTrader: (4)

Block the dump valve off to get the noise all the time!

TD series turbos are tough as old boots and will take it. Early VFs are fragile and won't, post VF30 should be ok though. My car runs a VF35 with no dump valve and is fine.

Ns04

eggy790

iTrader: (20)

cool, any affects on performance mate?

ross_wrx

The Forge Dump Valves are "serviceable" aren't they?

Is there a kit you can buy to do this?

zedy

ive got the same problem,,

since fitting a front mount, K&N Induction, and hks blow off valve at low revs say 2.5k wen u lift off the accelerator it goes ch ch ch ch, fluttery sound,, like a rally car???

is it supposed to do this??