acustic valve position
- Thread starter Foxspeed
- Start date
I think it's to reduce the noise the airbox makes, am sure Foxspeed will correct me if am wrong
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Wouldn't think that would reduce noise. Normally the car has resonator boxes (or just one) to reduce induction noise and not another opening so close to the airbox.
I modified almost all my airboxes from my cars and when I took the std intake pipe away and fitted a bigger one and placed it so that cold air would rush in, the intake sound was always louder than std :blink:
When I open my window (my R27) and accelerate in 2nd, 3nd and 4th with the gas pushed hummm 1/2 at least (it's more of a rpm based experience so doesn't really matter in which gear) I hear a deep intake sound around 2000-2700rpm and then it vanishes - the funny part is that when you don't accelerate enough it doesn't do it. So my thought was that this isn't an acoustic valve but more of a "extra" intake. The idea was that as you drive slower and on lower revs there is not so much air pressure in the primary intake pipe as air isn't pushed throu the grill in the pipe because of the lack of speed and when you pust the throttle to a point the valve opens and the engine gets precious air so it can accelerate better at lower revs. As the revs rise so does the speed and air pressure builds up in the main pipe so the extra pipe can be closed so no hot air gets in.
Just a thought ;/
The intake of the Clio reminds me of the BMC CDA system with the pipe you fit in the front bumper. Been reading some info from users of it and almost everyone complains about a small lack of power at small speed as the air is feed to the engine by only a small pipe and there is not enough speed to force the air in. The intake of the Clio is the same sort. A pipe that draws air from the grill. So maybe with that "extra" intake pipe Renault only wanted to solve this "problem".
Thinking loud again ;/
I modified almost all my airboxes from my cars and when I took the std intake pipe away and fitted a bigger one and placed it so that cold air would rush in, the intake sound was always louder than std :blink:
When I open my window (my R27) and accelerate in 2nd, 3nd and 4th with the gas pushed hummm 1/2 at least (it's more of a rpm based experience so doesn't really matter in which gear) I hear a deep intake sound around 2000-2700rpm and then it vanishes - the funny part is that when you don't accelerate enough it doesn't do it. So my thought was that this isn't an acoustic valve but more of a "extra" intake. The idea was that as you drive slower and on lower revs there is not so much air pressure in the primary intake pipe as air isn't pushed throu the grill in the pipe because of the lack of speed and when you pust the throttle to a point the valve opens and the engine gets precious air so it can accelerate better at lower revs. As the revs rise so does the speed and air pressure builds up in the main pipe so the extra pipe can be closed so no hot air gets in.
Just a thought ;/
The intake of the Clio reminds me of the BMC CDA system with the pipe you fit in the front bumper. Been reading some info from users of it and almost everyone complains about a small lack of power at small speed as the air is feed to the engine by only a small pipe and there is not enough speed to force the air in. The intake of the Clio is the same sort. A pipe that draws air from the grill. So maybe with that "extra" intake pipe Renault only wanted to solve this "problem".
Thinking loud again ;/
not so sure on the valve arrangement
its permanently open and is closed by vacuum off the inlet manifold controlled by a valve which in turn is via the engine ecu
had a vacuum guage on the pipe on mine and it didnt do anything :001_rolleyes:
the engine conforms to euro4 emission regs and i wonder if its something to do with drive-by noise regs
mine is permanently closed now and to be honest there is no "bad" effects so far
its permanently open and is closed by vacuum off the inlet manifold controlled by a valve which in turn is via the engine ecu
had a vacuum guage on the pipe on mine and it didnt do anything :001_rolleyes:
the engine conforms to euro4 emission regs and i wonder if its something to do with drive-by noise regs
mine is permanently closed now and to be honest there is no "bad" effects so far
Have you tried it in such a way that there is load on the engine? Not just revving it up and down while it's standing.
Dunno about the noise regulation hmmm
its the whole bit at the end of the red pipe - two 10mm nuts hold it in place - you can either remove it and leave the vacuum pipe and wiring connected and cable tie out of the way - or just use a self tapper screw to keep the inlet flat permanently shut :thumbup1:
..cool....will try later....I've noticed that the cool weather has made a subtle difference to the induction note....is this because the ECM is shutting the valve till the engine warms up?
My guess would be that the valve is there as a hot air feed from the engine bay.. can close when the engine is warm enough to get maximum power via teh cold feed from the grill? ?
As for the numbers and arrows they look like a manfacturing date stamp... one for month one for yr?
As for the numbers and arrows they look like a manfacturing date stamp... one for month one for yr?
Raptor6767
Gold Member
AFAIK that's the manufacturer code that specifies the series, material that the part is made of and the date.
It won't benifit cause it will draw hot air from inside the engine bay. If you can do a cold air feed it would surely be better but you can't get a pipe to the "second" grill cause you would have to cut a bit of the slam-panel and the coolant tank is in the way etc. think if you have xenons then there is no room on the other side for a feed either :blink:
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