NPP install issue
Thread Starter
Instructor
Joined: Jun 2007
Posts: 224
Likes: 0
From: port st. lucie Florida
NPP install issue
Installed NPP mufflers on my 11 GS this weekend. Fairly simple until I tried to access the "T" fitting on the back of the intake manifold to access vacuum to operate the muffler valves. Located it OK but even after removing the passenger side coil packs for access , the twisting motion on the fitting is a bit difficult. I am concerned I will break the fitting and since that is part of the brake booster vacuum fitting will cause more problems than I need .
Any thoughts on how to break or twist the fitting
Any thoughts on how to break or twist the fitting
Team Owner
Joined: Sep 2005
Posts: 20,352
Likes: 568
From: Ventura County, Calif
Common problem. I haven't done it but there are some ideas in here that might help. Good luck. 
http://forums.corvetteforum.com/c6-c...-box-kind.html
http://forums.corvetteforum.com/c6-c...-box-kind.html
Team Owner
Joined: Sep 2005
Posts: 20,352
Likes: 568
From: Ventura County, Calif
Hmmm.....works for me. Oh well here are some excerpts:
Hope those help.
I used an exact knife duct taped to a nutdriver. That gave me the length to get back there. I used the little plastic bar for leverage. Remember it is supposed to look like a barb fitting when you get done. Some have cut too close to the manifold taking the barb off..
Here is the Tee cut off, but held on by duct tape for illustration..
Here is the Tee cut off, but held on by duct tape for illustration..
I installed mine yesterday, what a pain!
I removed my coil pack assy., then I couldn't twist the 'T' cap off with my large paw.
So I took an spare 1/4" drive-3/8" Craftsman socket and ground a notch about 1/2 way down into the socket, 3/16" wide (same thickness of the 4 1/2" cutting wheel.
This makes the perfect tool to go over the plastic 'T', I then attached a 1/4" drive wheel to the socket and twisted that plastic "T" cap off.
Thinking I had the hard part done, I checked with a mirror and flash light to see that the hole was visible, it was!
So I next tried to install the vacuum hose after I blew it clear with conpressed air, My fat hand again cramped up, so I removed the valve cover too! I added a small amount of lube to help it slide on.
Finnaly after making my left wrist look like hamburger I was done, this was the hardest part of the job for me.
But the pain is worth it, as my car didn't come with NPP mufflers, and I knew I had to have this option after renting a Hertz Corvette with NPP exhaust last October in Vegas!!
Good luck and get a inspection mirror with an extension handle and plenty of light, and keep reminding yourself it's worth the pain.
I removed my coil pack assy., then I couldn't twist the 'T' cap off with my large paw.
So I took an spare 1/4" drive-3/8" Craftsman socket and ground a notch about 1/2 way down into the socket, 3/16" wide (same thickness of the 4 1/2" cutting wheel.
This makes the perfect tool to go over the plastic 'T', I then attached a 1/4" drive wheel to the socket and twisted that plastic "T" cap off.
Thinking I had the hard part done, I checked with a mirror and flash light to see that the hole was visible, it was!
So I next tried to install the vacuum hose after I blew it clear with conpressed air, My fat hand again cramped up, so I removed the valve cover too! I added a small amount of lube to help it slide on.
Finnaly after making my left wrist look like hamburger I was done, this was the hardest part of the job for me.
But the pain is worth it, as my car didn't come with NPP mufflers, and I knew I had to have this option after renting a Hertz Corvette with NPP exhaust last October in Vegas!!
Good luck and get a inspection mirror with an extension handle and plenty of light, and keep reminding yourself it's worth the pain.
I found that using a 12 mm socked will do the trick really well. A 1/4" drive ratchet and a short 12 mm socked will fit between the firewall and the motor. Then all you have to do is pull the ratchet toward you and it should snap right off. I have small hands and I beat then up pretty bad until I tried the socket. Once I did it, I wondered why I had made such a big deal out of it. My car is an 08, I am guessing all c6's are alike. Good luck.
Yes the vacuum cap is a PITA, no bs about that. Instructions now say try and twist and then cut if needed.
I have been able to twist some off, and some others I had to cut off, it all depends on the car.
I am glad you got it, and you should know that you have used the CORRECT GM vacuum tap area for bi-mode exhaust.
Here are a couple of pix of the offending vacuum cap:
Glad you have your bi-mode exhaust up and running.
Ben
I have been able to twist some off, and some others I had to cut off, it all depends on the car.
I am glad you got it, and you should know that you have used the CORRECT GM vacuum tap area for bi-mode exhaust.
Here are a couple of pix of the offending vacuum cap:
Glad you have your bi-mode exhaust up and running.
BenHope those help.
Racer
Joined: Mar 2009
Posts: 447
Likes: 0
From: Adkins Texas
The new NPP in a box kits should contain the EZ tap.
http://forums.corvetteforum.com/c6-t...-in-a-box.html
http://forums.corvetteforum.com/c6-t...-in-a-box.html
