Acoustic Valve?

[Daz Clio Cup]

All i wanna know is is it worth removing?
I've read that it restricts the airflow between idle and 4500rpm to increase torque,is this right?
Will i gain anything by taking it out?

 

[BenR]

by itself, no.

 

[Lagerlout]

I also to reduce noise iirc. although this man ^^ will know far more about than most.

I noticed a loss of torque when I fitted my Maxogen at about 4-5 kpm. Pulls stronger above that though.

 

[Daz Clio Cup]

by itself, no.

I'm upgrading to a performance panel filter, and cold air feeds, should i keep it or not?
I have already a full s/s decat custom system fitted, so induction noise is nothing i will notice!
Just trying to gauge if removing it will affect performance or not

 

[Neil G]

I'm running a similar setup at the moment (Green panel, sports cat and Stealth exhaust) but have left the valve in place.

TBH the design is pretty good....if you look at the grill there is an air deflector which flows cool air in to the top intake whilst the bottom one with the valve on is always cool.

I have contemplated removing the valve but have come to the conclusion that it really won't make much difference in the performance.

If you do remove it and it's much better let me know

 

[Fred@BTM]

remove and place in the bin

 

[Ali]

I also to reduce noise iirc. although this man ^^ will know far more about than most.

I noticed a loss of torque when I fitted my Maxogen at about 4-5 kpm. Pulls stronger above that though.

You shouldn't have lost diddlysquat!!! In terms of torque or Bhp.

 

[Neil G]

Can't be that bad can it?

I'm not fussed about sound but surely by removing this the car isn't going to gain any bhp/torque

 

[Daz Clio Cup]

remove and place in the bin

Why?

What exactly is it doing badly/ not doing?

Saying remove and bin doesn't help me in answering the question, what will i gain/lose from removing it?

Thanks

 

[Fred@BTM]

it just gets in the way and is crap IMO

IMO i think its a restriction

 

[Mr Melon]

I fitted my Viper and didnt know how to remove the valve so i sort of had the CAF resting on top of it (77mm CAF from the viper resting over top of the valve which has to be 65mm approx so it will be a bottle neck). I then was told how to remove the valve and the car feels alot better now and sounds a bit louder. Not sure if it will affect the normal airbox setup though, personally i wouldnt remove unless i was changing the CAF to a bigger 1.

 

[Lagerlout]

You shouldn't have lost diddlysquat!!! In terms of torque or Bhp.

Seems to be a bit of a flat spot more than anything else. Think she's running a little lean.

 

[Neil G]

it just gets in the way and is crap IMO

IMO i think its a restriction

Surely if this valve opens fully there shouldn't be any real restriction apart from the bends in the intake pipes/elbows?

 

[Fred@BTM]

its still a restriction

 

[BenR]

if you using the std airbox, leave it.

It remains open except for certain part throttle areas where you wont notice it as your not needing the flow.

Its not a restriction, the engine doesn't 'see' it.

 

[Daz Clio Cup]

if you using the std airbox, leave it.

It remains open except for certain part throttle areas where you wont notice it as your not needing the flow.

Its not a restriction, the engine doesn't 'see' it.

Would you say then the best thing for me to do would be cold air feeds to the airbox/valve and a performance filter?

 

[Neil G]

if you using the std airbox, leave it.

It remains open except for certain part throttle areas where you wont notice it as your not needing the flow.

Its not a restriction, the engine doesn't 'see' it.

Thanks for that....I was beginning to think I'd need to remove it so that's saved me some time.

The OE airbox has a pretty good supply of cold air from around the headlight for the top and down in the area fed with cold air from the vent under the bumper.....I don;t think using a 'positive pressure' airfeed like the Viper would make much difference.

 

[Ali]

Seems to be a bit of a flat spot more than anything else. Think she's running a little lean.

Possible...

 

[Fred@BTM]

Bin It!

 

[Neil G]

Why though.....is there any proof that this valve restricts airflow?

 

[BenR]

no

 

[ant]

think i prefer mine


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shoo! pesky OE feed and assorted valve thingum!

 

[Fred@BTM]

all the "quick clios" i've driven have removed it

 

[Lagerlout]

Ignore them Fred, it's the Panel Filter Evangelists again.

The standard airbox is the best.

 

[Neil G]

lol....of course the OE box is the best!

 

[George k]

I accept that it can probably be dispensed with when the car is modified and particularly when re-mapped, but as Renault are not charity, they must have a good reason for fitting it - does anyone actually know why?

 

[BenR]

Ignore them Fred, it's the Panel Filter Evangelists again.

The standard airbox is the best.

i dont think thats the arguement at all, i think its about whether running the valve on the std box makes a difference at all, in which case i say...no.


I dont see a point removing it as it is open when your at low manifold vacuum, and it takes a significant amount of vacuum to close it, which means it must be closed only at very very low throttle angles.

And in my flow testing i have since discovered that in any applications except massively high frequency use (10,000rpm +) there is no benefit of a straight bore over a butterfly, the engine just does not 'see' it.