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NPP Volume Control
Thread Starter
Tech Contributor
Joined: Oct 2008
Posts: 1,378
Likes: 11
From: St Louis MO
NPP Volume Control
For grins and giggles I hooked up my hand operated vacuum pump tester directly to the NPP plumbing to play with different settings of the butterflies and adjust the sound.
It actually works pretty well to set different vacuum levels and the tone goes from quiet to full blast and any place in between.
It actually works pretty well to set different vacuum levels and the tone goes from quiet to full blast and any place in between.
Last edited by StKnoWhere; Apr 29, 2011 at 10:42 PM.
Thread Starter
Tech Contributor
Joined: Oct 2008
Posts: 1,378
Likes: 11
From: St Louis MO
Around 5" vacuum it there's less low frequency, under full throttle the tone is a little more a scream like an exotic (Ferrari).
Around 8" vacuum the drone driving uphill on the highway drops out but it still sounds nice overall. You can still hear rev matching on down shifts with the A6.
They close around 10-12" vacuum.
Press the relief lever and your back to wide open thunder.
I may not bother installing the NPP controller I bought.
Last edited by StKnoWhere; Apr 29, 2011 at 10:45 PM.
Instructor
Joined: Mar 2011
Posts: 152
Likes: 0
From: Iowa
Anyway to scale this setup down, you think? It would require some form of small electrical vacuum pump, I suppose?
It'd be pretty sweet to have a dial built into the center console to control the valves!
It'd be pretty sweet to have a dial built into the center console to control the valves!
Pro
Joined: Sep 2010
Posts: 606
Likes: 0
From: Riverlea OH-IO
I haven't played a lot yet but it's actually more like a bass/treble control than volume so you can get several distinct sounds.
Around 5" vacuum it there's less low frequency, under full throttle the tone is a little more a scream like an exotic (Ferrari).
Around 8" vacuum the drone driving uphill on the highway drops out but it still sounds nice overall. You can still hear rev matching on down shifts with the A6.
They close around 10-12" vacuum.
Press the relief lever and your back to wide open thunder.
I may not bother installing the NPP controller I bought.
Around 5" vacuum it there's less low frequency, under full throttle the tone is a little more a scream like an exotic (Ferrari).
Around 8" vacuum the drone driving uphill on the highway drops out but it still sounds nice overall. You can still hear rev matching on down shifts with the A6.
They close around 10-12" vacuum.
Press the relief lever and your back to wide open thunder.
I may not bother installing the NPP controller I bought.
You'll have to keep us posted on your findings.
coop
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Thread Starter
Tech Contributor
Joined: Oct 2008
Posts: 1,378
Likes: 11
From: St Louis MO