zedimpreza

I have a 2001 bug eye wrx.

Today i fitted a bailey dump valve and when i rev the car standing still it works.

However when i drive under full load it makes no noise at all.

But if i press the clutch while driving and let the car coast and then rev it, it works!

Any ideas what it might be?

joz8968

iTrader: (13)

By 'works' I assume you mean the 'whoosh' noise of a vent-to-air dv that you've fitted?

It will only make this noise when you come off the throttle. Hence why it makes the noise when revving at at rest (makes the noise on the release of the throttle pedal).

When you're accelerating the valve remains shut, but as soon as you come off the throttle the valve opens, venting the positive pressure still present in the intake system to atmosphere, hence the distinctive noise.

zedimpreza

The problem is that when im accelerating in gear and let of the throttle there is no noise at all.

But if im in neutral or letting the car coast and i rev it and release the throttle, it works!

Any more thoughts?

joz8968

iTrader: (13)

Ah sorry. Stumped I'm afraid.

IainMilford

iTrader: (15)

are you accelerating hard?? some dump valves are adjustable and may only dump at very high revs and vice versa

zedimpreza

Accelerating very hard.

There is no loss of boost or performance and it goes very well in every gear.

The baileys one isnt adjustable.

sponners

iTrader: (4)

bit of a strange one

your car is also producing a lot more boost when driving as apposed to reving it in neutral.......so should be a lot louder when driving.

have you got a really loud exhaust?

wrighty338

iTrader: (33)

you installed it correct? pics?

zedimpreza

Definitely installed correctly.

The car is not standard.

It has a downpipe, decat and prodrive backbox.

Also has been remapped by TSL.

So the dump valve works under light load, but under heavy load no sound?

Any further thoughts?

wrighty338

iTrader: (33)

No, not if its deffinatly installed correctly

zedimpreza

Problem solved!

It was full of and dirt from the previous car it was on.

Under hard acceleration it was getting stuck.

I opened it up, cleaned it all out and sprayed some wd40 in.

Works a treat now!

joz8968

iTrader: (13)

Good for you, mate .

Thanks for the heads-up, helps add to the ol' 'knowledge is power' database an' all that...

I can see the logic behind that diagnosis... The sustained force from the boost when accelerating causing the dirty valve to stick closed after coming off the boost, compared to the relatively small periods of force on it when revving at idle.

IainMilford

iTrader: (15)

amazing what a clean up can do