dump valves.
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I'm Finding My Feet Here Now
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From: south wales
dump valves.
im about to buy a FRS and the first thing i wanna do is fit a dump valve. what is the bet make to choose? i was also wondering wot the difference is between dump valves that do a normal choof lie a bailey dump valve and the other type that flutters??? been baffling me for ages wot the difference is? can any one help me??? lol thanks.
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From: The Dark Side of the Moon...
Yes, the flutter (or "chatter" as it is known) is when you DON'T have a dumpvalve 
For info please refer to my earlier post in someone elses thread
For info please refer to my earlier post in someone elses thread
Originally Posted by Thrush
Chatter occurs when escess, built up charge gases get stuck between the inlet butterfly and the turbo when you snap the throttle shut when changing gear of lifting off for example.
If you have a dump valve (either to atmosphere or a recirc type that vents backinto the airbox) these gases are dispelled either to atmosphere or re-circulated back to the airbox.
If you have neither, the gases are stuck, If there is enough force and enough gas, they hit the now blocked off throttle butterfy, turn round and go the opposite way down the charge carrier. They exit through the turbocharger and the noise you hear, the "chatter" is the sound of the excess charge air being "chopped" by the turbine blades.
So, you will get more chatter if you have no dumpvalve at all. There is an argument as to at what point you NEED a dumpvalve due to the mass airflow going backwards through the turbine blades causing turbo-stall and possibly damaging the bearings and shaft.
If you have a dump valve (either to atmosphere or a recirc type that vents backinto the airbox) these gases are dispelled either to atmosphere or re-circulated back to the airbox.
If you have neither, the gases are stuck, If there is enough force and enough gas, they hit the now blocked off throttle butterfy, turn round and go the opposite way down the charge carrier. They exit through the turbocharger and the noise you hear, the "chatter" is the sound of the excess charge air being "chopped" by the turbine blades.
So, you will get more chatter if you have no dumpvalve at all. There is an argument as to at what point you NEED a dumpvalve due to the mass airflow going backwards through the turbine blades causing turbo-stall and possibly damaging the bearings and shaft.
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I'm Finding My Feet Here Now
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From: south wales
im surprised at the replies there? why not get a dump valve? i think it sounds absolutely awesome!! and with regard to the chatter im sure im on about summin else. my friend had a recirc valve onhis seat cupra and that made a noise like a pigeon rather than a choof. im sure that werent gases hitting the blades fo the turbo??? it seems the focus is pretty poor wen cold on tickover ne way. my fathers and my bros often cut out wen cold.
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From: Mongsville, wiping Jimbo.'s spastic arse.
Originally Posted by Robert_Cox
im surprised at the replies there? why not get a dump valve? i think it sounds absolutely awesome!! and with regard to the chatter im sure im on about summin else. my friend had a recirc valve onhis seat cupra and that made a noise like a pigeon rather than a choof. im sure that werent gases hitting the blades fo the turbo??? it seems the focus is pretty poor wen cold on tickover ne way. my fathers and my bros often cut out wen cold.
good for you pal!
get a dump valve
they rule!
PassionFord Post Whore!!
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dont bother getting a dump valve the FRs has a re ciculating valve anyways get the K&Ng2 and it makes the standard re circ valve chuff like a atmospheric dump vavle and has the added bonus of not stalling your car 
DEYTUKURJERBS
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From: North Korea
the chattering/fluttering noise is air coming back out the turbo inlet when coming off throttle.
a dumpvalve will reduce if not remove that noise.
only reason some people think that a DV does it is when they fit aftermarket dumpers that have an overly strong spring in it, and that means not enough air comes out the dumper, so lots more come out the turbo inlet than before, and hence the chattering noise.
trust me, been there, done this, 6-7 years ago up until today, as have countless others here.
a dumpvalve will reduce if not remove that noise.
only reason some people think that a DV does it is when they fit aftermarket dumpers that have an overly strong spring in it, and that means not enough air comes out the dumper, so lots more come out the turbo inlet than before, and hence the chattering noise.
trust me, been there, done this, 6-7 years ago up until today, as have countless others here.
PassionFord Post Whore!!
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Originally Posted by RichardPON
Originally Posted by Kev.H
has the added bonus of not stalling your car
so for the hassle it could cause... just either keep the re circ unit or uprate to another aftermarket re circ unit fit a G2 K&N and it dumps anyways 
PassionFord Post Whore!!
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Originally Posted by RichardPON
Really?
I thought they only stalled when you fitted the wrong dump valve
I thought they only stalled when you fitted the wrong dump valve
read lots of peeps having problems that all just TRYING to help the guy
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Don't get mardy you miserable bastard.
Just don't remember any dump valves causing FRS to stall when we used to fit them.
Would hardly be acceptable to fit a product on a customer's car that did that now would it?
Just don't remember any dump valves causing FRS to stall when we used to fit them.
Would hardly be acceptable to fit a product on a customer's car that did that now would it?
PassionFord Post Whore!!
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Originally Posted by RichardPON
Don't get mardy you miserable bastard.
Just don't remember any dump valves causing FRS to stall when we used to fit them.
Would hardly be acceptable to fit a product on a customer's car that did that now would it?
Just don't remember any dump valves causing FRS to stall when we used to fit them.
Would hardly be acceptable to fit a product on a customer's car that did that now would it?
maybe you should spend more time on FRS forums just saying what ive seen I havent fitted a DV but I assume you remove the factory item near the airbox if you do
maybe peeps are running two 
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Originally Posted by Kev.H
Originally Posted by RichardPON
Don't get mardy you miserable bastard.
Just don't remember any dump valves causing FRS to stall when we used to fit them.
Would hardly be acceptable to fit a product on a customer's car that did that now would it?
Just don't remember any dump valves causing FRS to stall when we used to fit them.
Would hardly be acceptable to fit a product on a customer's car that did that now would it?
Ooops
True about the Jap cars though - people always harp on about VTAs on MR2 turbos with AFM, but mine has caused no stalling.............
PassionFord Post Whore!!
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Originally Posted by RichardPON
Originally Posted by Kev.H
Originally Posted by RichardPON
Don't get mardy you miserable bastard.
Just don't remember any dump valves causing FRS to stall when we used to fit them.
Would hardly be acceptable to fit a product on a customer's car that did that now would it?
Just don't remember any dump valves causing FRS to stall when we used to fit them.
Would hardly be acceptable to fit a product on a customer's car that did that now would it?
Ooops
True about the Jap cars though - people always harp on about VTAs on MR2 turbos with AFM, but mine has caused no stalling.............
never assume only post if you have facts blah blah 
I was just offering the guy another route which I KNOW works
PassionFord Post Whore!!
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Originally Posted by Robert_Cox
wots the difference between a gen 2 k&N and a normal 57i kit#? price? power? and wen we say it choofs with it, how loud r we talkng???
difference er power didnt really notice noise defo louder price double
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