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Hello Fellow C6ers,
I am in the beginning process to convert my 2005 coupe to have the NPP mufflers. I have purchased a pair of used factory NPP mufflers and was going to buy the "NPP in a Box" set up today and asked the fellow on the phone about the EZ Tap for the LS2 and he said something along the lines of he had never heard of that and the kit he supplies only connects to the port on the back of the intake manifold. There are other suppliers that have the option to purchase the EZ Tap set up for the LS2 motors.
So I ask if the 2005 LS2 Corvette motor can use the EZ Tap or do I have to use the port on the back of the manifold?
Any comments or suggestions would be helpful.
Thanks
Last edited by Teamjnz; Dec 2, 2020 at 12:38 AM.
Reason: Spelling
There is an EZ Tap option for LS2 or LS3. You have to specify which you want when you purchase. This website shows the choice. I don't know anything about them; just using it as an example. You specify LS2 or LS3 under "options".
There may not even be a small vacuum port on the back of LS2 manifolds. I believe it was put there specifically for NPP vacuum on LS3 manifolds. With the LS2 never having had an NPP option, it may not be there. You can always tap into the brake booster line. Just have to get a little creative with fittings.
Hello Fellow C6ers,
I am in the beginning process to convert my 2005 coupe to have the NPP mufflers. I have purchased a pair of used factory NPP mufflers and was going to buy the "NPP in a Box" set up today and asked the fellow on the phone about the EZ Tap for the LS2 and he said something along the lines of he had never heard of that and the kit he supplies only connects to the port on the back of the intake manifold. There are other suppliers that have the option to purchase the EZ Tap set up for the LS2 motors.
So I ask if the 2005 LS2 Corvette motor can use the EZ Tap or do I have to use the port on the back of the manifold?
Any comments or suggestions would be helpful.
Thanks
When you say you bought used NPP mufflers, did you buy just the mufflers or did you buy the mufflers with a 2.5" over-the-axle pipe? If the latter, was it from an '08? I ask this, since the '09-'13 is not a simple bolt on swap to an '05, due to the pipe angles being changed on the passenger side. However, you could cut both mufflers off their respective pipes and weld the NPP muffler to your '05 pipe. The driver side should bolt up without issues.
Originally Posted by old motorhead
There may not even be a small vacuum port on the back of LS2 manifolds. I believe it was put there specifically for NPP vacuum on LS3 manifolds. With the LS2 never having had an NPP option, it may not be there. You can always tap into the brake booster line. Just have to get a little creative with fittings.
You are correct about no vacuum nipple on the LS2 manifold. The LS3 was the first and the nipple on cars without the NPP option, had a twist-off cap on the manifold. That was to make it easy for the assembly line worker to remove the cap when the car was ordered with the NPP option.
The NPP in a box, initially had a self-contained vacuum pump vs obtaining vacuum from the engine. That was good to keep the valves closed under engine load, but bad because the pumps failed early. IIRC, the change to a solenoid to control the vacuum happened in mid-'08.
When you say you bought used NPP mufflers, did you buy just the mufflers or did you buy the mufflers with a 2.5" over-the-axle pipe? If the latter, was it from an '08? I ask this, since the '09-'13 is not a simple bolt on swap to an '05, due to the pipe angles being changed on the passenger side. However, you could cut both mufflers off their respective pipes and weld the NPP muffler to your '05 pipe. The driver side should bolt up without issues.
I purchased Z06 NPP mufflers with the 3" pipe so they definitely won't be plug and play. I will be cutting off the 3" at the back of the muffler as well as cutting the 2.5" off and rewelding them the NPP mufflers. 👍
I purchased Z06 NPP mufflers with the 3" pipe so they definitely won't be plug and play. I will be cutting off the 3" at the back of the muffler as well as cutting the 2.5" off and rewelding them the NPP mufflers. 👍
If you measure from the can to about 2" back on your 2.5" pipe and the Z06 pipe and put a mark parallel to the can and another parallel to the seam of the muffler, then when you cut the pipes off, you'll have a reference both radially and lengthwise when you weld things back together. I've done this for my '08 and a few times for friends. Cut the 2.5" pipe real close to the can, but leave about 3/4" remaining on the Z06 muffler. That way you'll have a bit of adjustment.
Pics of mine.
There may not even be a small vacuum port on the back of LS2 manifolds. I believe it was put there specifically for NPP vacuum on LS3 manifolds. With the LS2 never having had an NPP option, it may not be there. You can always tap into the brake booster line. Just have to get a little creative with fittings.
Would be nice if you knew what you were talking about, the tap for NPP is on the back of an LS2 manifold and the 05-07 vetted were delivered with the NPP option
Would be nice if you knew what you were talking about, the tap for NPP is on the back of an LS2 manifold and the 05-07 vetted were delivered with the NPP option
2008 was the first year for NPP exhaust on a non-Z06 C6. Just sayin'...
2008 was the first year for NPP exhaust on a non-Z06 C6. Just sayin'...
That's true, since the Z06 never had a NPP option. The very similar muffler was standard equipment on a Z06 and designated as a bi-mode muffler.
NPP is a RPO code, not the name of a muffler.
Great tip on the how to. The mufflers are the same size as the ones currently in the car. Also the 3" pipe has been squeezed down to fit a 2.5" hole in the Z06 mufflers. Using your tip I maybe able to fit the original pipe into the 3" pipe at the back of the can and weld it up.👍 I was looking around for pipe reducers to mate the 2 pipes but your tip sounds like a viable solution with purchasing the reducers. Thanks
Originally Posted by HOXXOH
If you measure from the can to about 2" back on your 2.5" pipe and the Z06 pipe and put a mark parallel to the can and another parallel to the seam of the muffler, then when you cut the pipes off, you'll have a reference both radially and lengthwise when you weld things back together. I've done this for my '08 and a few times for friends. Cut the 2.5" pipe real close to the can, but leave about 3/4" remaining on the Z06 muffler. That way you'll have a bit of adjustment.
Pics of mine.
That's true, since the Z06 never had a NPP option. The very similar muffler was standard equipment on a Z06 and designated as a bi-mode muffler.
NPP is a RPO code, not the name of a muffler.
Ahh. The silent question is answered. I was wondering what the acronym NPP was for.. It's not a name but a RPO code like Z51. 🙂
Done!!
This past weekend I cut off the OEM muffler and welded on OEM Bi-Mode mufflers and installed a Mild to Wild controller. Now it sounds like a Corvette should.
Love it!
NPP in a box, 2005 LS2
