wastegate flutter
disconnect your dump valve. the noise is the compressed air being forced back trough the turbine blades the wrong way when the throttle shuts and the air has no where to go.
will not do your car much good tho.
will not do your car much good tho.
Originally Posted by jjones
disconnect your dump valve. the noise is the compressed air being forced back trough the turbine blades the wrong way when the throttle shuts and the air has no where to go.
will not do your car much good tho.
will not do your car much good tho.
a) being audible
b)bouncing off its seal
confirmation anyone?
I am assuming the waste gate and the dump valve are seperate components
can anyone link to a schematic?
I think we could all benefit from a little education on these items..
Originally Posted by Watchdog
i heard you can get these for n/a cars.....i want one for my 106.,,,and a flammer kit to give it that rally look and feel....awesome!

And I've just posted on the dump valve thread as to what causes the chatter and how to get it on your scoob. Provided you can afford to buy a new turbo once in a while that is
Originally Posted by GRIFF007
I am assuming the waste gate and the dump valve are seperate components
the wastegate is located within the turbo.
dumb valve released excess pressure when the throttle shuts. hence the vent to atmosphere valves pshhhhttt on gear changes (when you shut the throttle off).
wastgegate allows exhaust gas to bypass the turbine blades to stop the turbo making more boost. this is how a bleed valve (dawe) works. it bleeds off pressure from the actuator so it doesn't open to a higher pressure (boost).
it is commonly called wastegate flutter but in reality is the turbine stalling on back pressure.
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Originally Posted by Graz
You are taking the **** I hope? 
And I've just posted on the dump valve thread as to what causes the chatter and how to get it on your scoob. Provided you can afford to buy a new turbo once in a while that is

And I've just posted on the dump valve thread as to what causes the chatter and how to get it on your scoob. Provided you can afford to buy a new turbo once in a while that is

Originally Posted by jjones
the dump valve - is located on the intercooler.
the wastegate is located within the turbo.
dumb valve released excess pressure when the throttle shuts. hence the vent to atmosphere valves pshhhhttt on gear changes (when you shut the throttle off).
wastgegate allows exhaust gas to bypass the turbine blades to stop the turbo making more boost. this is how a bleed valve (dawe) works. it bleeds off pressure from the actuator so it doesn't open to a higher pressure (boost).
it is commonly called wastegate flutter but in reality is the turbine stalling on back pressure.
the wastegate is located within the turbo.
dumb valve released excess pressure when the throttle shuts. hence the vent to atmosphere valves pshhhhttt on gear changes (when you shut the throttle off).
wastgegate allows exhaust gas to bypass the turbine blades to stop the turbo making more boost. this is how a bleed valve (dawe) works. it bleeds off pressure from the actuator so it doesn't open to a higher pressure (boost).
it is commonly called wastegate flutter but in reality is the turbine stalling on back pressure.
So the 'flutter' I heard on the road Esprit and we all hear on comp cars is due to unsilenced (ie not routed back into main exhaust) wastegates porting direct to atmos? - this would presumably charged with flame though...
Originally Posted by Watchdog
i heard you can get these for n/a cars.....i want one for my 106.,,,and a flammer kit to give it that rally look and feel....awesome!
fake blow off valves and flamer kits indeed,i bet you got a subaru bonnet scoop on your 106 havnt you

mark
Originally Posted by ARM-Scooby
doesnt a waste gate reduce the life of the turbo?
As in any closed loop feedback system you have to have some controlling mechanism as if left alone it will spiral out of all control. This is what the wastegate does. At the desired boost level the wastegate opens to bypass some of the exhaust gasses around the turbo, it then opens and closes to keep the target boost constant. All turbos (AFAIK) have them, either integral (all unmodified scoobies) to the turbo itself or external.
Originally Posted by Watchdog
i heard you can get these for n/a cars.....i want one for my 106.,,,and a flammer kit to give it that rally look and feel....awesome!
Dazza
To get "proper" chatter/compressor surge (which is what we're all talking about) on throttle closures, remove dump valve and blank off hole where it should be (as per rally cars - WILL shorten life of turbo bearings +/- risk catastrophic compressor failure with time).
To get a similar effect with less risk (on MHI and IHI VF3x turbos, NOT VF2x turbos as have a fragile compressor), fit a forge recirc DV with the red spring and a couple of shims. It'll still "dump" on full throttle closures over a certain pressure, but will chatter on partial throttle lifts. Probably will still shorten bearing life, but hey turbos aren't built to last forever
Simon
PS you won't hear anything unless you've got an induction kit fitted as the resonator box removes the sound with the normal induction setup.
To get a similar effect with less risk (on MHI and IHI VF3x turbos, NOT VF2x turbos as have a fragile compressor), fit a forge recirc DV with the red spring and a couple of shims. It'll still "dump" on full throttle closures over a certain pressure, but will chatter on partial throttle lifts. Probably will still shorten bearing life, but hey turbos aren't built to last forever

Simon
PS you won't hear anything unless you've got an induction kit fitted as the resonator box removes the sound with the normal induction setup.
I seem to have read somewhere that the wastgate on the WR1 is different to standard and makes that chattering sound. Apparently it was one of the ways they got the extra power, as it controls max boost more accurately (or something like that but I may be showing my ignorance)!!
Our cossie westfield has the wastegate removed. It makes some impressive chattering noises...
Sounds good when timed to coincide with going under bridges.
Makes the unsuspecting jump a bit tooo......
Didnt think it had a negative effect on turbo life though.
Sounds good when timed to coincide with going under bridges. Makes the unsuspecting jump a bit tooo......
Didnt think it had a negative effect on turbo life though.
Originally Posted by pbee
nah the wr1 suposedly has a 3port boost solenoid which helps control higher levels of boost compared to the standard 2 port.
did anyone confirm this ?
did anyone confirm this ?
Originally Posted by Nikko2
Our cossie westfield has the wastegate removed. It makes some impressive chattering noises...
Sounds good when timed to coincide with going under bridges.
Makes the unsuspecting jump a bit tooo......
Didnt think it had a negative effect on turbo life though.
Sounds good when timed to coincide with going under bridges. Makes the unsuspecting jump a bit tooo......
Didnt think it had a negative effect on turbo life though.
I've got a my97 classic, I had the intercooler off a while back to clean etc.
When I re-fitted the standard dv I fitted it the opposite way round ( so the pressure holds it closed ) when testing after the car now makes the fluttering sound when you come off the throttle!
Anyone else tried this?
Is it likely to cause damage?
When I re-fitted the standard dv I fitted it the opposite way round ( so the pressure holds it closed ) when testing after the car now makes the fluttering sound when you come off the throttle!
Anyone else tried this?
Is it likely to cause damage?
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