James1
Member
Registered: 23rd Feb 04
Location: North Nottinghamshire: Drives Evolution VIII MR
User status: Offline
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Do u lose performence by adding 1 to your car, External Dump Valves im talking about
Premature loss of Pressure in the Turbo or anything?
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Nismo
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Registered: 12th Sep 02
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depends what cars , sum you do sum you dont
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James1
Member
Registered: 23rd Feb 04
Location: North Nottinghamshire: Drives Evolution VIII MR
User status: Offline
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On an Evo VIII?
good or bad move?
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Tom
Member
Registered: 3rd Apr 02
Location: Wirral, Merseyside
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Bad I suspect.
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MatthewR
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Registered: 21st Oct 02
Location: Rickmansworth
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Wud u need one?
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Patrick
Member
Registered: 25th Apr 02
Location: SE London
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I've decided against a dump valve for the moment.
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James1
Member
Registered: 23rd Feb 04
Location: North Nottinghamshire: Drives Evolution VIII MR
User status: Offline
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On what grounds?
+ Side I love the sound, Good for turning heads,
Bad side - Possible damage to Turbo loss in performence
[Edited on 07-05-2004 by James1]
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MatthewR
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Registered: 21st Oct 02
Location: Rickmansworth
User status: Offline
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Evo v111 dont need a dump valve to turn heads it sounds sweet as it is!!!
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James1
Member
Registered: 23rd Feb 04
Location: North Nottinghamshire: Drives Evolution VIII MR
User status: Offline
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nahh m8, Nothing funnier then Driving past some fucks on pavement and dumping off! makes me laugh everytime, Gives old ladies and young kids right shock
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MatthewR
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Registered: 21st Oct 02
Location: Rickmansworth
User status: Offline
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James1
Member
Registered: 23rd Feb 04
Location: North Nottinghamshire: Drives Evolution VIII MR
User status: Offline
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If its fucking the car however its gotta go
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micra_pete
Premium Member
Registered: 23rd Apr 03
Location: West Yorkshire
User status: Offline
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why would you put a dump valve on a evo VIII?
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nik
Member
Registered: 19th Jun 00
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they all have them as standard ffs  just not a gay girly neddy one
[Edited on 07-05-2004 by nik]
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micra_pete
Premium Member
Registered: 23rd Apr 03
Location: West Yorkshire
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i assumed he ment a ned type, which i think he did
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nik
Member
Registered: 19th Jun 00
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standard one on mine with hks superflow induction kit, that sounds a bit like a dumpvalve just not as loud 
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Marc
Member
Registered: 11th Aug 02
Location: York
User status: Offline
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VTAs are for people with small dicks. And yes, you will lose performance.
Ross 
[Edited on 07-05-2004 by 16vmarc]
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vibrio
Banned
Registered: 28th Feb 01
Location: POAH
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quote:
Originally posted by 16vmarc
Recircs are for people with small dicks. And yes, you will lose performance.
no atmospheric ones are for people with small dicks
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Marc
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Registered: 11th Aug 02
Location: York
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shit thats what i meant!!
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tiga77
Member
Registered: 6th May 04
Location: Ilkeston, Derbyshire. MR2 Turbo GT T-Bar
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If your car has got an 'air flow meter' then with an aftermarket dump valve (BOV) you are essentially blowing out 'metered' air through the D/Valve.
When this happens there will be more fuel in the chamber and less air than needed - this is running rich.
So the engine will then retard the air fuel mixture to account for the lack of air by reducing the fuel - thus running lean. So as this keeps happening the air/fuel mixture is constanly being messed about. This incorrect mixture causes detonation and as a result kills your pistons etc.
Also if you have an air flow meter and a atmospheric dump valve the car will run like crap and stall all the time etc. That is why I cant run one on my mr2 turbo. It is more about looking after your engine than 'losing performance'.
However if you dont have an air flow meter you are fine. 
Impreza's, early MR2 turbos etc all have air flow meter so it is not recommended to put an atmospheric dump valve on. Dont know about evos tho sos.
HTH 
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vibrio
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Registered: 28th Feb 01
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quote:
Originally posted by tiga77
If your car has got an 'air flow meter' then with an aftermarket dump valve (BOV) you are essentially blowing out 'metered' air through the D/Valve.
When this happens there will be more fuel in the chamber and less air than needed - this is running rich.
So the engine will then retard the air fuel mixture to account for the lack of air by reducing the fuel - thus running lean. So as this keeps happening the air/fuel mixture is constanly being messed about. This incorrect mixture causes detonation and as a result kills your pistons etc.
Also if you have an air flow meter and a atmospheric dump valve the car will run like crap and stall all the time etc. That is why I cant run one on my mr2 turbo. It is more about looking after your engine than 'losing performance'.
However if you dont have an air flow meter you are fine.
Impreza's, early MR2 turbos etc all have air flow meter so it is not recommended to put an atmospheric dump valve on. Dont know about evos tho sos.
HTH
as for detonation happening. not likely atmos DVs make cars run rich any way not lean
also for cars with air flow meters you need to run twin piston DV's like bailey DV 26 or forge 004
[Edited on 07-05-2004 by vibrio]
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tiga77
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Registered: 6th May 04
Location: Ilkeston, Derbyshire. MR2 Turbo GT T-Bar
User status: Offline
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The twin piston dump valves only solve stalling issues by having 2 flanges. One that remains shut when the car is not using pressure to stop any stalling issues, the other flange opens and closes just like a single piston dump valve.
As for the detonation :- yes the dump valve does make the cars run rich - HOWEVER as the ECU and knock sensor detect the car is running rich, it adjusts the air/fuel mixture accordingly and flips it the other way - so it runs lean. THis is how the detonation causes. The ECU doesnt reaslise that all of the preivously 'metered' air has escaped into the atmosphere and that is how the car runs lean.
It doesnt stay running lean - it will revert back to running rich, but when the ECU and knock sensor detect this again, the same thing happens hence running lean.
Loads of articles on the net if you search for dump valve and air flow meter problems. There was even an investigation by a motorsport expert who clarified the issue - which is basically what I have just said in the last couple of messages.
HTH
[Edited on 07-05-2004 by tiga77]
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vibrio
Banned
Registered: 28th Feb 01
Location: POAH
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quote:
Originally posted by tiga77
The twin piston dump valves only solve stalling issues by having 2 flanges. One that remains shut when the car is not using pressure to stop any stalling issues, the other flange opens and closes just like a single piston dump valve.
As for the detonation :- yes the dump valve does make the cars run rich - HOWEVER as the ECU and knock sensor detect the car is running rich, it adjusts the air/fuel mixture accordingly and flips it the other way - so it runs lean. THis is how the detonation causes. The ECU doesnt reaslise that all of the preivously 'metered' air has escaped into the atmosphere and that is how the car runs lean.
It doesnt stay running lean - it will revert back to running rich, but when the ECU and knock sensor detect this again, the same thing happens hence running lean.
Loads of articles on the net if you search for dump valve and air flow meter problems. There was even an investigation by a motorsport expert who clarified the issue - which is basically what I have just said in the last couple of messages.
HTH
[Edited on 07-05-2004 by tiga77]
well no such problems on my car also I suspect any rich/lean runnign of the car will be so insignificantly small it won't actually affect much of the running
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tiga77
Member
Registered: 6th May 04
Location: Ilkeston, Derbyshire. MR2 Turbo GT T-Bar
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Vibrio,
If you attached an air/fuel gauge you would be surprised !!
Take a look at this photo - as aresult of detonation through a BOV.
http://www.imoc.co.uk/users/upload/detonation.jpg
Need I say any more? Take my advice or dont, just trying to help those that care for their cars. 
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vibrio
Banned
Registered: 28th Feb 01
Location: POAH
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I have to say that is just a picture of an engine (don;t prove anything) I don't believe for one second that a DV did that. I suspect it was due to other causes.
I would take your advice exept there are plenty of cars runngin around with atmos DV's wich run totally fine. I personally run a recirc because it does not produce lag like an atmos one does.
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tiga77
Member
Registered: 6th May 04
Location: Ilkeston, Derbyshire. MR2 Turbo GT T-Bar
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They may run fine - Ive never disputed that! If you stripped them down and looked at the damage being caused, you will see what is in the photo.
Ive worked on cars for years, my mate owns a car garage and a lot of the cars are high perfomance items, so without being rude I know a 'fair deal'. I cant be done with an argument, I know the facts and what Ive pointed out is the truth (proven truth).
I dont care what other people do with their cars, I was merely trying to point out the facts for the guy with the evo. Whether he takes the advice or not, I aint bothered - it aint gonna change my life or bank balance is it?
Glad you run a recirc tho
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