I need some help.
Team Owner
Joined: Sep 1999
Posts: 41,732
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From: Springfield MO
Running the valves open at lower RPMs might be hurting your low end torque(but I doubt if you can feel it, just as I doubt you can feel the additional 6 HP increase when the valves are open at higer RPMs).
There is an aftermarket kit that allows you to have a fulling functioning NPP exhaust.
Thread Starter
Instructor
Joined: Mar 2012
Posts: 188
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From: DFW Texas
If you leave the valves in the open position .......... The engine has always produced those numbers. The base, non NPP axle back muffler system, chokes things down. That's why the Corvette w/ NPP can advertise higher numbers. Simply said, when the valves open, the system is more free flowing, thus the higher hp/torque rating. You'd need a dynamometer to really see the difference. What you need to do is buy the M2W accuator kit from one of the forum vendors that will make the NPP functional.
Team Owner
Joined: Sep 2005
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From: Big Bend Country, TX
St. Jude Donor '06-'07-'08-'09-'10-'11-'12-'13-'14-'15- '16-'17-‘18-‘19-'20-'21
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Thread Starter
Instructor
Joined: Mar 2012
Posts: 188
Likes: 4
From: DFW Texas
Team Owner
Joined: Sep 2005
Posts: 29,113
Likes: 2,194
From: Big Bend Country, TX
St. Jude Donor '06-'07-'08-'09-'10-'11-'12-'13-'14-'15- '16-'17-‘18-‘19-'20-'21
NCM Lifetime Member
This is gonna be easy then. Get hold of Anthony or Bobby at LG Motorsports or, Matt at 21st Century and explain what you want to do. Either shop can do the job and get the vacuum assy you need to make the NPP functional.
Safety Car
Joined: Oct 2003
Posts: 4,024
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From: Loveland CO to Central Coast CA
Team Owner
Joined: Sep 1999
Posts: 41,732
Likes: 1,718
From: Springfield MO
Or, if you want to save money, buy a hand vacuum pump at harbor frieght and some vacuum hose. Drill a small hole in the floor of your rear hatch, run the tubing under the carpet up to the front, and hook up the hand operated vacuum pump. When you want to close the exhaust valves, give the hand pump a couple of squeezes and when you want them open, release the vacuum.
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Team Owner
Joined: Sep 2005
Posts: 29,113
Likes: 2,194
From: Big Bend Country, TX
St. Jude Donor '06-'07-'08-'09-'10-'11-'12-'13-'14-'15- '16-'17-‘18-‘19-'20-'21
NCM Lifetime Member
Or, if you want to save money, buy a hand vacuum pump at harbor frieght and some vacuum hose. Drill a small hole in the floor of your rear hatch, run the tubing under the carpet up to the front, and hook up the hand operated vacuum pump. When you want to close the exhaust valves, give the hand pump a couple of squeezes and when you want them open, release the vacuum.
Team Owner
Joined: Sep 2005
Posts: 29,113
Likes: 2,194
From: Big Bend Country, TX
St. Jude Donor '06-'07-'08-'09-'10-'11-'12-'13-'14-'15- '16-'17-‘18-‘19-'20-'21
NCM Lifetime Member
Thread Starter
Instructor
Joined: Mar 2012
Posts: 188
Likes: 4
From: DFW Texas
Team Owner
Joined: Sep 2005
Posts: 29,113
Likes: 2,194
From: Big Bend Country, TX
St. Jude Donor '06-'07-'08-'09-'10-'11-'12-'13-'14-'15- '16-'17-‘18-‘19-'20-'21
NCM Lifetime Member
That kit lets you open or close at will. Your car doesn't have the computer module that controls the factory NPP.
Team Owner
Joined: Sep 1999
Posts: 41,732
Likes: 1,718
From: Springfield MO
I was originally going to offer that as another source of a vacuum, but decided to stick strictly with the hand pump. Some things are better left up to the imagination and not spelled out.
Team Owner
Joined: Sep 2005
Posts: 29,113
Likes: 2,194
From: Big Bend Country, TX
St. Jude Donor '06-'07-'08-'09-'10-'11-'12-'13-'14-'15- '16-'17-‘18-‘19-'20-'21
NCM Lifetime Member
Safety Car
Joined: Oct 2003
Posts: 4,024
Likes: 13
From: Loveland CO to Central Coast CA
