acoustic valve?

[THE SKULL]

what is an acoustic valve and is it worth removing?

 

[gaz44]

http://www.youtube.com/watch?v=w4XWOpLIm3E

 

[T. 12 E E D.]

what is an acoustic valve and is it worth removing?

I've got no idea myself fella but last time i was at 182kev's he mentioned he'd removed his send him a pm

 

[Henry]

it's bolted to the horn bracket, behind the n/s headlamp and is an inlet vacuum operated butterfly valve designed to reduce induction noise. and, 'no'.

 

[THE SKULL]

cheers men!!....just looking for cost free mods!!
one of the tuning firms on here include it in there stage one tuning package,just a load of pony then?

 

[Wests Renault]

i was looking at doing this mod what the pros and cons?

 

[Henry]

it just makes more noise really; if you disconnect the pipe from the airbox infront of the battery, that'll give you an idea

 

[joep87]

Do you need to remove the valve completely to get the sound or can you just remove the wires and block the pipe?

 

[Jonny1*2]

it doesn't make much difference to the sound mate. I removed mine to get more access for a caf into the arch.

 

[ben81]

cheers men!!....just looking for cost free mods!!
one of the tuning firms on here include it in there stage one tuning package,just a load of pony then?

It's not worth doing alone unless you just want a bit of intake noise. Does go well with a remap and de-cat though!

 

[0-100mphin15sec]

Made a noticeable difference when removed mine.

 

[skiptontweed]

I took the butterfly out of mine and left everything else connected. The valve body acts as a nice mount for the air feed up to the the airbox.

I can't say Ive noticed much of a difference, maybe a bit more noise.

Id remove it completely if I needed the room inside the wheelarch.

 

[clio carl]

where is the valve located? any pics please

 

[mattjk]

nearside front arch

 

[Tucker]

it will make a noticable difference if you fit an itg panel filter, remove the valve and uprate the CAF

 

[DrewBear11]

I've never understood this valve, is it closed when the engine is cold, when openwhen the engine is warm or something ? All i can see it does is restrict an air feed into the airbox ???:S

 

[skiptontweed]

I've never understood this valve, is it closed when the engine is cold, when openwhen the engine is warm or something ? All i can see it does is restrict an air feed into the airbox ???:S

The acoustic valve body houses an oval butterfly valve - a bit like a throttle valve.

The valve appears to close using intake vacuum, a spring holds the valve shut and engine vacuum opens the valve against this spring. However, the vacuum line from the intake manifold to the valve appears to have a little green valve in it conected to a couple of wires. This may mean that the ecu can decide when to 'allow' the vacuum to close the valve.

As for why the acoustic valve is there, Im really not sure. Whats clear is that it has cost a few quid to design/manufacture so there must be a good reason. Maybe its there for noise attenuation or something.