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Old Feb 2, 2017 | 11:45 AM
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Default NPP modifications

Hello Friends,

I have NPP exhaust with a Mild to Wild device. I have been using it with some wire rope clamps on the shafts so the butterflys can't close - they stay open about a quarter inch or so. Nice V8 sound... not annoying. I'm finding that I rarely like having them wide open - too loud. I'm now wanting to let them close all the way when "on" (minivan quiet) and then open slightly to hear the growl when I hit the "off" button.

Does anyone have an idea about what is the best way to let them open slightly, but have an adjustment as well? I thought of some stainless cable around the moving part anchored to the diaphragm bracket. Some barrel clamps with a hex screw would allow for some adjustment. Any experience with this or ideas?

Thanks, Monte
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Old Feb 3, 2017 | 09:27 AM
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I have not done this myself but why cant you put a small clamp on the back side where the actuator is? Some people call it a bug nut or wire rope clamp.
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Old Feb 3, 2017 | 09:44 AM
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Split shaft collar. Be sure to get stainless or they'll rust.
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Old Feb 3, 2017 | 09:44 AM
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http://www.globalindustrial.com/p/mo...FQqraQodktsO7g
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Old Feb 3, 2017 | 09:45 AM
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By the way, that's not the correct size, but rather just a pic of the type of collar you'll need.
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Old Feb 3, 2017 | 09:47 AM
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http://www.globalindustrial.com/p/mo...Fc62wAodcKgDoA

Actually, this is a better representation of the split collar. I thought the other one was split, but it's not. But the first link does show it in stainless.
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Old Feb 3, 2017 | 09:48 AM
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I found mine at a Sears Hardware Store, but eventually took them off and now leave my NPP open all the time.
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Old Feb 3, 2017 | 10:04 AM
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Originally Posted by airmed2
I found mine at a Sears Hardware Store, but eventually took them off and now leave my NPP open all the time.
Thanks airmed! I'm thinking of making a bracket with a threaded hole that I can run a bolt through. This bolt will make contact with the moving arm and allow me to adjust how much noise I want with a simple turn. Wide open all the time gets on my nerves after a while. Closed is like driving my minivan - great for long trips though. Looking for a way to quickly have the best of both worlds. I will post pics when I get it figured out.

High regards, Monte
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Old Feb 3, 2017 | 11:05 AM
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Yeah, that would probably be easier than the collar. First, the collars are a bear to install unless you have micro fingers. Then you have to get them positioned just right on the shaft in order to limit the opening of the baffle. I actually had mine positioned to limit the amount the baffles closed. Because I didn't get stainless, they actually began rusting to the shaft.

Good luck with your modification, and be sure to follow it up with some pictures.
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