Spec me a Dump Valve

andi said:
Don't Saabs run without any DV? But a DV on a car that chatters and I will hunt you down.
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Your more than welcome to drive for 4 hours to find an 8 year old car that dumps :p
 
Saabs used a closed air recirc system if you fit a dump valve it will run rich everytime the valve releases air.
 
agw_01 said:
AFAIK, that's what the twin piston DV's are for.
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The only thing that twin piston dump valves do is prevent air leakage at idle, which is only half of the problem. Dumping metered air to atmosphere cause the engine to breifly run very rich, giving hesitation when changing gear and giving puffs of black smoke out out of the exhausts.

The 9-3 I *think* does have a Mass Air Flow sensor (sometimes called Air Mass Meter). If this is the case then unless you value silly noises over performance and life of your engine then stick with the standard one, or if you can't bear keeping any money in your pocket get an aftermarket recirculating valve.
 
panthro said:
Explain how a properly installed, good quality dump valve can do more harm than good?
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overfuelling
Bore wash
Poor throttle response
Jerky gear-changes

And mine was a £250 HKS SSQV. Even a re-map doesn't solve the problems they cause.

Don't get me wrong, up to a month ago I wouldn't have taken any notice to those that poo poo'd an atmos DV. Now I won't be getting another.

However, convincing those that have atmos DVs that they aren't that good an idea is like Chris Columbus trying to convince everyone that the world isn't flat.

Read that on SNet and just had to quote it somewhere :)
 
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Good thing about the SSQV is that you can recirc it but at the price you should hope so.
 
agw_01 said:
Band give off a typical pppppttttttttscccccccchhhhhhhh sound. Very loud and very cool.
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You are aware that those are mutually exclusive, right? DVs rate just below blue underbody neons in the mod stakes as far as I'm concerned. If you have a car which isn't normally normally available in turbo form and you've fitted a DV to let every know that yours is a turbo, then aside from the fact it's slowly wrecking your engine, just maybe. But to get a car everyone knows is turbo charged and to then fit a DV just so you can remind the slower-thinking members of the public who might actually care that it's turbo-charged seems kinda pointless to me. Unless you get one of those novelty ones that makes silly noises...


M
 
Meridian said:
You are aware that those are mutually exclusive, right? DVs rate just below blue underbody neons in the mod stakes as far as I'm concerned. If you have a car which isn't normally normally available in turbo form and you've fitted a DV to let every know that yours is a turbo, then aside from the fact it's slowly wrecking your engine, just maybe. But to get a car everyone knows is turbo charged and to then fit a DV just so you can remind the slower-thinking members of the public who might actually care that it's turbo-charged seems kinda pointless to me. Unless you get one of those novelty ones that makes silly noises...


M
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I'm with him... It might make a *whoosh* sound, but as my simple 2.0 N/A MR2 pulls past you with a proper engine roar then you'll soon know your place. O, and don't forget to mention it to the insurance companies. I'm sure they'll love you...
 
Kicking up a fuss about why people like dump valves... okayyyyyy, that's a new one for me.

Why bother saying anything at all? Yeah sure, some people might have them down as a chavvy mod (how many chavs own cars with dump valves???) but just because I like the sound and get a big grin everytime I hear a car with one, why the need to say anything?
 
ci_newman said:
I'm with him... It might make a *whoosh* sound, but as my simple 2.0 N/A MR2 pulls past you with a proper engine roar then you'll soon know your place. O, and don't forget to mention it to the insurance companies. I'm sure they'll love you...
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I hope there is 3 lanes on this road so I can get past both of you :p
 
There are only two types of cars where DVs are acceptable IMO.


Very, very highly modified Japanese cars.


Very old, modified sleepers with a turbo engine. Such as a Ford Anglia 105E with a Nissan 1.8 turbo lump and ~230bhp. So it squats down, ****s off, and goes vrrrrrrmmmm*tish* to give people an idea of what's under the bonnet.


I'm going for the 2nd one ;)
 
Hate said:
I hope there is 3 lanes on this road so I can get past both of you :p
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There's plenty of motorways down south :D

I know my car isn't the fastest on the road, but likewise I don't spend a quarter of the cars value on fairly pointless Mods. A £200 DV on a £1000 car (ok not 25%) which will only serve to shorten the engines life and decrease MPG for a fancy *whoosh* sound. Sticking the MP3 on a CD and playing it loud will have the same effect.
 
Well, I have a twin piston DV36 on mine. I love it and wont be going back to recirc. Makes a great sounds which I really think suits the car.

This one has been discussed at length on FccUK. How can you be overfuelling when you're not pressing the accelerator? Plus the amount of air thats actually dumpted is tiny compared to the volume of air the engine intakes.
 
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