adamS2RST

OK, it does do it, not loudly and prenounced as it is mfi, but ever since my turbo has started to get louder it is chatting, im not running more boost and it is not over boosting, what could it be? Air leak? cant find one, checked all hoses / pipes, car runs fine and this has happend within the last week! It sounds great and doesnt seem as if there is a problem but in the back of my mind I am slightly concerned

M.A.D.RST

What do you mean ever since your turbo has started to get louder?

When i take my dump valve off and really nail it mine chatters, well more like a loud chirp from the actuator(i think)!

KSA-Cossie

iTrader: (4)

I'm running 18psi through a grs cooler and it chatters it's head off

m_nettleship

Im running 15psi woth a new stage 2 hybrid, and it doesent make a noise at all. so what does make the chatter nois????????????????????????????????????????

ballin

iTrader: (1)

did you put a jubilee on the bung mate?
also mine chatters a bit when i take the DV off....only got it on there cos new turbo and wanted a bit off failsafe while the new actuator was set!!

ballin

iTrader: (1)

m_nettleship, the chatter is always there if you have no DV, its basically air being forced the wrong way through the turbine causing it to stall.
the reason you dont hear it on a ERST is because the metering unit muffles the sound.

cone filter will make it slightly more audible and then some are louder than others anyway!

adamS2RST

Rich, yea I did try a jubilee on the d/v take off bung, but it is still the same. I have left it on for good measure anyway.

Think it may be a case of "see how long the turbo lasts" then?

vroooom ptssssh

mine chatters on 7psi with no d/v obv, but my turbo oil seals r fecked........doubt thats anything to do with it tho!

adamS2RST

Dave u telling me ur probs are sorted now with the new tank?!

vroooom ptssssh

not yet

Stoo

Ksao you have a cone filter mate?Or standard airbox?

KSA-Cossie

iTrader: (4)

Hi stoo,i have a quickshift racing cone filter on mine.

vroooom ptssssh

sucking in some nice hot air losing u bhp and raising inlet temps it's proven too.....

Stoo

I changed my K&N back to airbox,but would stick it back on to hear the chatter for a change Quite like the noise actually

AVA are very to the point when it comes to conefilters Open bonnett "First off,your filter's shit"

adamS2RST

LOL

KSA-Cossie

iTrader: (4)

231bhp aint doin' to bad lol

Stoo

Im sure you could spare a couple bhp anyway buddy

KSA-Cossie

iTrader: (4)

Yeah best not be too greedy eh! i have a heat shield covering the filter and a pipe routing fresh cold air to it aswell.

Thrush

iTrader: (1)

The metering unit doesn't muffle the sound as such - it actually stops air exiting back thru it and out the air filter.

If you go and take the air filter or air box off your RST, you will see a big round metal "plate". Push this plate with your finger and it will go down. this is what happens when air is sucked in via the air filter/box. Basically there is an arm attached to this plate, and it pivots. As it pivots fuel is metered equal to the amount of air entering the engine (judged by how far the plate has opened)

Now, this plate can open donwards, and it closes upwards. But it can only go so far up then it stops. When it stops it i fully closed.... You lot following me?

Like a throttle butterfly - when you lift off the throttle to chage gear, slow down etc, the throttle butterfly snaps shut preventing air from entering the plenum. Likewise the plate in the metering unit closes preventing more air from entering the turbo/charge air system, etc.... With a normal dump valve in place, the air trapped between the throttle butterfly and the metering unit plate can escape thru said dump valve.

But with no dumpvalve, the charge air cannot escape. Still follow me?

It can't go in the plenum as the butterfly is shut and it can't exit via the air filter as the metering plate is shut..... or at least it should be Bet your lost now

"Chatter" is the term given to the noise you hear when charge air is "chopped" by the tubine blades as it passes back through the turbochager and out the air filter.

BUT! On an MFi ERST the charge air should not be able to escape through the air filter as the metering flap should now be shut, preventing air from escaping....

So how does your RST get chatter? Logic points to the fact that your metering units are not doing the job they should be doing, and allowing air to escape when they shouldn't be...

The only other explanation is that air is escaping from between the turbo and the metering unit, of which there should only be one section of pipe/tubeing.

Get both your metering units and this piping checked out, as if either are leaking air then your fueling is not going to be right - ie: if your metering unit is allowing air to escape back thru it, then how can it be functioning properly, therefore how do you know it is metering the fuel in ratio to the air flow? Or, if the pipe between turbo and metering unit is allowing air to escape, then how do you know it isn't bleeding it off under boost/throttle, therefore the already metered fuel/air ratio is screwed up again as there is now more fuel than air since some has been bled off......

Worth checking lads, deffo worht checking - all in all could well lead to under or over fuelling both of which usually result in destroyed pistons/heads/rods

adamS2RST

Well, I have all new samco's, unless they are fucked then it is doubtful they are leaking, metering head, well it is a possability. I need to get the car setup, so I will see what they say, but for now I cant say im too worried, car will be coming off the road soon

vroooom ptssssh

yup ava are straight to the point, and rightly so you'd be surprised at how shit cones really are.....

T28 RST

My car chatters quiet loud

Lemon S2

Mine's got a bit of chatter but it got a lot louder when one of the wires going from the starter motor & the alternator fooked and was not putting any charge to the battery & the ECU.

Don't know if this helps at all.

vroooom ptssssh

nope, cant c that helping at all lemons

Lemon S2

oh well, was worth a try

vroooom ptssssh

very true

adamS2RST

LOL my alt did sound louder recently believe it or not! It has quietend down again now tho and I have rigged up my volt meter and it is fine

SassyRS

My frst chatters like a biatch when the dv's not connected and its
bunged off!

i thought all turbos did? is that noise not the wastegate?

adamS2RST

FRST'S chatter because they run the later EFI management and most escorts run the MFI. On the EFI you have a filter directly off the turbo and no metering head, hence the more louder prenounced chatter

But See Thrush's more "detailed" description for the exact reasons for it all!

SassyRS

Thrush

iTrader: (1)

Exactly right Adam FRST's and your Cossie's chatter like good'ns as there is no AFM (air/fuel meter) between the turbo and the air filter. Remove the noise-restrictive air box (or jsut turn up the boost with it on) and you will hear it all the time.....

But your ERST's and also stuff like Vauxhall Cav/Cali turbo's generally don't chatter because of the AFM situated between turbocharger and air filter.....

SassyRS

We also have 2 series 2's and they chatter just as much

oh well maybe i just have talkative cars