Hi all,,, just wondering if any one can help ,which dump valve is it that gives off the chattering sound when u lift off gas or change gear,,

Ain't quite sure if it is the dump valve heard it on a few now ,first heard on rally cars,

 

Rally cars dont use dump valves, they use anti lag systems and trust me you wont want to use one of those on the road! (well not unless you want to keep buying turbo's )

Tony

 

Hi mate

The chatter noise is normally associated with the turbo blades stalling the chatter noise is audible through the induction system.

Some DV do mimick this sound a little, not sure on the type though

 

Mine does it, forge dump valve, connected to front mount intercooler piping.

 

I think you will find that the chattering is coming from the wastegate on WRC cars

 

Noise is not from the wastegate......... this has been done to death on here and if you search the answer will become clear..... its due to air being returned to the turbo and beng chopped by the compressor blades and audible through the inlet as previously stated,my forge vta with red spring does it on minimal boost before the spring can be overcome and the air vented out,its only slight and no where near the level the wrc cars do because o the anti lag systems they run,this severly limits turbo life,on a rally car where the engine is rebuilt regulary thats ok,on a road car not so

 

I bow to your superior knowledge chap

 

only know because someone else posted it up before

 

If you want a twittering noise all you need to do is put an open induction kit on. That then allows out the sound of the compressor stall. Hence why you often don't get it on a full dump with an aftermarket valve, because they have a pretty good 'dumping rate' for want of a better term. If you do a lot of jiggling the throttle in and out of boost you'll head compressor stall more noticeably because your dump valve will not fully open, therefore allowing some pressurised charge to back up against the compressor wheel.

 

It will do the same with the standad airbox still fitted too if the wing resonator is removed...... noise is more audible since i removed mine

 

On previous cars that i've had a VTA DV fitted, the baileys piston one on the GTi-R gave like a double whistle, (sshhhh, ssshhh), rather than others that done one Pittussshh.

Maybe it was because it was a piston one, but that is the closest i've experienced to the noise you're after.

 

I have a GFB Stealth dumpvalve from Scoobyclinic, when thats turned one way or another, it chatters just like the wrc car.