That is the question, folks.

Just interested in knowing people's thoughts on these atmospheric dump valves. I've still got the original in the car which recycles the air quietly? I am currently looking at upgrading and replacing her original parts as an improvements package.

I just remember walking back home years ago and seeing a renault 5 GT turbo howling and I immediately thought "Chavs". Problem is now, years later and none the wiser, I want the same sound effects.

Before I take this any further,I just wanted to find out the following :
- does it sound noisy inside the car?
-does it enhance the performance of the car in any way?
-do you get disapproving looks from pedestrians and other motorists?

I think they sound utterly ridiculous......

... You did ask.

I run a HKS atmospheric. It's noisy and makes a sound every time I change gear. I love it.

Ah, the age old debate

Well there's always a lot of debate about this, basically it's down to personal preference, however...

...the 20vt is designed to work with a recirculating dump value (the quiet type) so if you use an atmospheric dump valve it will (technically) adversely affect the fueling of the car...but having said that lots of people run atmospheric dump valves without any noticeable adverse effects.

There's certainly no performance improvement, although there is a lot of extra noise both in and out of the car

Gareth

The twin piston atmos DV's are the ones that cause no problems and if you go down the 'my car sounds like it's really mean' or 'watch out, I'm turbo charged' route (like I merrily do) then get one of these.

I love the whoooosh sound, not too loud in the cabin, effects my performance as I keep up shifting, downshifting for no apparent reason

My old coop had the Whoosh, and I enjoyed it! I'm going for a recirc this time. The car is designed for it, after all. You still hear it dumping the air back into the inlet if you run an aftermarket air filter.

Oh, you've got to laugh. If you don't you'd SSsssccccrrrreeeeaaaaaammmmmmmm!!!!!! :-)

I prefer the sound the Forge DV006 recirc one makes when you have a staight induction pipe, I think atmospheric dump valves sound like the car is sneezing.

vrooom ACHOO!, vrooooooooom ACHOO!

Mine sounds fantastic. K&N 57i kit with a Forge DV006. Subtle but you know you've got a turbo!

I've got a very subtle one that flutters. It sounds good though. You cant hear it inside the car. I dont know what make/model it is as it was on the car when I bought it.

Does anyone know what this type is?

A broken one?

LOL I was thinking that Matt, there shouldn't be any flutter!

i'm with Phil - just come back from flea and loved every whooooosh for the whole 280 miles round trip

I've heard similar on other cars and if it's broken then it certainly sounds consistant.

Anything to add to your LOL then? As I'm no expert what should I be doing about this possibly broken item?

Is the flutter not due to the lack of airbox I've got a k&n and a twin piston baileys and I get a do do do ptuuusssshhhh obv the do do do bit is the air rushing back past the blades if the turbine and the ptuuussshh is the dump valve although on hot days can sound like a little tiny sneeze lol

That coupled with my tub noise an my straight through system makes for a very noisy drive and I love it specially coming through towns obv you get all the old people lookin in disapproval but certainly turns heads of all ages

Well, a flutter (or pigeon) sound is sometimes associated with a non working dump valve (or having no dump valve fitted) because a dump valve is designed to divert the air from the turbo out of the system, and if the air isn't diverted then it goes back into the turbo and the fluttering sound is the air hitting the turbo blades - you get the same effect/sound if you blow into a handheld fan.

Different dump valves / air box combos make different sounds so it doesn't mean there's definitely something wrong with yours, but that's why when you mentioned flutter people started talking about broken bits

Gareth

The missus has gotta astra turbo obviously
It's a different car so the setup is probably different but as soon as she put an induction kit on she gained the flutter

As far as I'm aware if the intake goes straight to the turbo and not through a metering unit your get the flutter I had a few years back a series 2 rs turbo and one of my mates had a fiesta rs turbo now his inlet went straight to the inlet on the the turbo and mine went through a metering unit both had k&n and his would flutter and mine wouldn't which was a bit annoying as they were virtually the same engine yurbo powered cvh

If you get flutter then the dump valve isnt doing it's job. If it's not broken then maybe it's too stiff so it's opening as it was designed to do but the pressure is still going back through the turbo as well. You can get different strength springs in some of them designed for different boost levels.

I've never heard a dump valve that makes a noise anything like compressor surge, so as far as I'm aware that kind of noise always comes from the turbo.

With my standard dumpvalve I get loud flutter

That's what I was saying the flutters from the turbo due to k&n and te ptuuusssshhhh is from me dump valve I see what your saying though as the dump valves supposta dump the excess air when changing gear or when you let off so obv it's not working properly tbh I like the mixture of the two so aren't I the lucky one lol

The K&N has nothing to do with it though, just makes it a bit more audible. The flutter is due to the dump valve.

Exactly that's what I said, if I had a standard airbox on then you wouldn't hear it obv the dump valve isn't dumping as should which is allowing the air to rush back past the blades thats not being dumped, think it's just stiff as recently it's stopped fluttering

As said the wifes coupe made no sound until I put a pipercross induction on it then hey presto flutter

I have a Bailey DV26 and I get flutter at lower revs.

Happy days that makes two of us lol

At low revs you will - I do.

I took my DV26 apart to clean, didnt put it back together properly and ended up with flutter all through the rev range - reason being the rubber seal around the valve had become trapped, jamming it shut. Fixed this and its fine now

Also had a copy HKS SSQV; never did get it to dump properly despite fiddling with it ALOT. Just fluttered nearly all the time amd affected performance no end; felt like you were going to launch yourself through the windscreen when changing up....

The flutter IS QUALITY, had quite a few people saying how it sounded awesome as I steamed past!!

Some say it damages your turbo, some say it doesn'tI get paranoid so I replaced my old bosch with forge. I swiftly got rid of my K&Ni because the lady like sigh made me want to strip naked and roll on burning broken glass whilst beating myself.

QUALITY

I've got a Turbo XS dump valve on mine.

Ergh!