dump valve causing rich mixture
06 March 2002, 09:46 AM
#1
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OK, let's understand - this - it up to an individual to choose, there are always people who hate VTAs.
Let's ask the serious question....
....who can explain to me the advantage of a VTA - from a technical perspective?
Why does it make your car run better - not worse?
Trout
PS I have heard that those underbody neon strip lights can really improve a standing quarter time - any comments anyone whilst we are here?
[Edited by Trout - 6/3/2002 9:53:30 AM]
Let's ask the serious question....
....who can explain to me the advantage of a VTA - from a technical perspective?
Why does it make your car run better - not worse?
Trout
PS I have heard that those underbody neon strip lights can really improve a standing quarter time - any comments anyone whilst we are here?
[Edited by Trout - 6/3/2002 9:53:30 AM]
31 May 2002, 11:44 PM
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I have a 94 wrx which i have just fitted a collins atmos dump valve to but the tail pipe of my exhaust is now really sooted up since i fitted the dump valve , will the dump valve cause any engine damage
01 June 2002, 06:01 AM
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The Subaru ECU is designed to run with a recirc valve and fuels to compensate for the extra air returning through the induction system.
A dump to atmos does not provide this air and so the car WILL run rich.
DTA valves offer no advantage over a good recirc IMHO. All style and no substance.
Trout
A dump to atmos does not provide this air and so the car WILL run rich.
DTA valves offer no advantage over a good recirc IMHO. All style and no substance.
Trout
01 June 2002, 08:04 PM
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What sort of proof are you after? As the good man Trout points out the airflow meter has already metered this air and it is now intermittently leaking so it will use more fuel.
01 June 2002, 11:50 PM
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I didnt ask for proof,i know there is NO difference to my fuel consumption on my scooby(1yr on rec/8months on atmo)but there always somebody who hates atmos and preferes recs.
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02 June 2002, 08:03 AM
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Planky,
I wasn't 'hating' VTAs - I was merely commenting that they are a complete waste of time and money - to be frank.
And if it is pretty noise you want - my chirruping recirc is probably louder than most VTAs I have heard on Scoob!
And from the technical perpective - yes it will make the car run rich sporadically as you release boost. Damage - nothing serious.
Trout
I wasn't 'hating' VTAs - I was merely commenting that they are a complete waste of time and money - to be frank.
And if it is pretty noise you want - my chirruping recirc is probably louder than most VTAs I have heard on Scoob!
And from the technical perpective - yes it will make the car run rich sporadically as you release boost. Damage - nothing serious.
Trout
02 June 2002, 11:43 AM
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As well as being rich, it will use more fuel absolute as the air that has leaked instead of being recirculated results in more vacuum in the inlet tract = more airflow across MAF = wider injector pulse widths.
03 June 2002, 12:00 AM
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RT im NOT mistaken my cars doesnt use anymore more fuel and most of my mates havent seen any change in fuel consumption.
anyway its up to the individual to choose.
anyway its up to the individual to choose.
03 June 2002, 01:28 AM
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MarkF,
But as standard, they run stupidly rich anyway so it's even more stupidly rich with a VTA DV.
There is no chance of it running anywhere near lean if everything is working correctly.....
Matt
Don't worry about it! I'd rather my car was running slightly rich than slightly lean
There is no chance of it running anywhere near lean if everything is working correctly.....
Matt
03 June 2002, 02:08 AM
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Quote:
"RT im NOT mistaken my cars doesnt use anymore more fuel and most of my mates havent seen any change in fuel consumption.
anyway its up to the individual to choose. "
I never questioned your right to choose.
I am simply telling you that you (and your mates) are wrong. It is not a question of using more fuel, but having less air to mix the fuel with, as all of it has escaped while making the pssst!
Anyway, it's up to you. Go ask any person worth their salt, and they'll tell you that the only way to run an atmospheric BOV is to use MAP instead of MAF for ECU load.
Its a fact.
"RT im NOT mistaken my cars doesnt use anymore more fuel and most of my mates havent seen any change in fuel consumption.
anyway its up to the individual to choose. "
I never questioned your right to choose.
I am simply telling you that you (and your mates) are wrong. It is not a question of using more fuel, but having less air to mix the fuel with, as all of it has escaped while making the pssst!
Anyway, it's up to you. Go ask any person worth their salt, and they'll tell you that the only way to run an atmospheric BOV is to use MAP instead of MAF for ECU load.
Its a fact.
03 June 2002, 02:48 PM
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trout....
You have not heard an HKS SSQ dump valve on a scoob then..... i can defo say they are alot louder than a recirculating one..... one of the main reasons for the recirculating DV is so it is quiter....!
Dan
You have not heard an HKS SSQ dump valve on a scoob then..... i can defo say they are alot louder than a recirculating one..... one of the main reasons for the recirculating DV is so it is quiter....!
Dan
03 June 2002, 05:30 PM
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RT,
it was standard - but then I changed intercooler to a Phase 1 IC so I needed to buy an aftermarket one - got a Forge that has been shimmed to leak more slowly - holds the boost a shade longer for gearchanging on track and makes a WRC chirping noise (I know the latter is unnecessary!)
Trout
it was standard - but then I changed intercooler to a Phase 1 IC so I needed to buy an aftermarket one - got a Forge that has been shimmed to leak more slowly - holds the boost a shade longer for gearchanging on track and makes a WRC chirping noise (I know the latter is unnecessary!)
Trout
04 June 2002, 07:33 PM
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WEBSTER STOP WINDING THESE PEOPLE UP AND TELL THEM YOU ARE A FULLY TRAINED MOTOR MECHANIC. MINE RUNS RICH AS WELL BUT F£$K IT, IT'S FAST. THANKS FOR THE HELP TODAY I KNOW THE COLOUR LOOKS RUBBISH & IWILL DO SOMETHING ABOUT IT IN 6 WEEKS TIME.
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