fast_ford_uk

right, ive read through pages and pages on here but not found much, whats the best dv to fit on a s2 that will give you the 'chatter' sound am i right in saying that bailey are shite and forge sound good?
any comments on these?
dan

buggynut

None

chatter sound comes from the turbo fans stalling not the DV

turn the boost up on the turbo if you have a bleed valve or get a hybrid upgrade

Oranoco

The chatter sound is the noise of teh compressed air traveling the wrong way through the turbo when the throttle is closed.

On an Escort you are unlikely to hear much if any of this noise as the metering unit muffles it completely.

Wouldn't bother with any dumpvalve on the car at all though as in my experience they cause problems rather than solve any.

Mr Shannon

Convert to efi and run it without one

Ad4m RST

Yup only way really

vroooom ptssssh

oh, and dont just "turn the boost up"

matt p

WTF the fuck you want a turkey for??

Or for that matter adump valve repent and have neither!!!!

PeterD

Dont worry about adump valve mate, waste of 80 quid, which could get you an hour on the rollers for a decent setup

PeterRST

iTrader: (1)

That might sound chavvy now. But you should be able to get chatter without converting to EFI. What you'd probably need is a dump valve that only blows out a very small amount of air. So that the compressor blades are stalling but the noise of it can escape into environment.

I once had to try something on my car. Didn't come on boost, to find out if the turbo is OK I pulled the hose off the actuator. You actually heard it chattering then. DO NOT TRY THIS AT HOME THOUGH, A BIT TOO MUCH THROTTLE FOR A BIT TOO LONG AND YOU'LL MOST LIKELY BLOW YOUR ENGINE!!!!

TGTURBO

CONVERT IT TO EFI

Turbocabbie

I would'nt run a dump valve even on a MFI as they usually idle shite with them

allbluepete

just heard my ex dumpvalved mfi car chattering for the first time today,it sounds fucking amazing,will probably start pissing me off after a couple of weeks like the dump valve did though

lewis_lisa

how do you remove your dumpvalve as im planning on doing this

SafeChav

Remove it, and you need to securely block off the hole where the DV was and also the small vacuum pipe that was attached to it

Diamonds.

iTrader: (2)

my MFI S2 does chatter quite loud

smitsturbo

why are dump valves bad for rs turbos?

Maxxeh

is the Venturi Dump Valve (Twin Piston) any good?

Is it any loader than the Normal Dump valve?

allbluepete

have you got an external wastegate then ,or running about 20 psi boost?have heard mfi cars chatter a wee bit but they are usually not very loud though

Diamonds.

iTrader: (2)

no mate no external. she's running 14psi at the mo

PeterRST

iTrader: (1)

How have you set up the boost? With a bleed valve? If you're bleeding a lot of air away from the actuator without connecting the third hose to the metering unit/ airbox that air (which comes directly from the compressor housing) could also carry the chatter sound into environment. However that's only a thought, don't know if it works that way.

Escort.Cosworth

I dont see the problem with a dumpvalve on a Rs Turbo I have one and runs spot on dont get any problems what so ever! Also ran the car without one aswell and its just the same

Diamonds.

iTrader: (2)

i found on mine when i had a dump valve on it wasnt as smooth between gear changes if driving normally.....bit of fun in the car quick changes etc...was very fine

steven botes

if you want a dump valve and chatter , get yourself an adjustable dump valve with a bolt on the top. the dump valve is supposed to mimimse chatter , it is actually the compressed air stalling the compressor wheel
adjust this bolt until you get the desired dumping and chatter. this can also be done with a needle bleed valve teed into the air line that goes to the dv
if i recall , this is achieved by turning the bolt in
found that all the dv did was shorten the times between wheelspin at the strip , sounds good though!

PeterRST

iTrader: (1)

That's pretty much what I was thinking about, Steven. But AFAIK the TwinPiston D/V from Baileys is the only one, that's not causing trouble with MFI. Bleed valve in the vacuum hose to the dumper would also cause an air leak, I'm afraid.

SafeChav

They all have the same effect, which is between gear changes and when coming off the throttle to over-run, when the DV opens it allows the metering head flap to briefly return to completely closed, which cuts the fuel supply off briefly, which obviously it should NEVER do as long as the engines running.

The result is an un-smooth response when coming off the throttle from boost which can get quite annoying as it makes the car jolt a little bit

PeterRST

iTrader: (1)

...which isn't too healthy for gearbox, driveshafts, CV joints, etc...

SafeChav

Bingo

Or your back if your an old fart lol