Functioning NPP for $50

[idealer]

Great right up Deke736. Will be doing this soon. My NPP mufflers are being shipped on monday, meanwhile I am getting parts together. I think I will use high performance silicone vacuum hose. The name speaks for itself- I hope.

[idealer]

Originally Posted by Shawno72

Great write up. I am purchasing a zl1 exhaust in a few days fr my Lfx. Can't wait to hear it

Me too. Seams we drive almost the same car except that my is a vert.

[Shawno72]

Originally Posted by idealer

Great right up Deke736. Will be doing this soon. My NPP mufflers are being shipped on monday, meanwhile I am getting parts together. I think I will use high performance silicone vacuum hose. The name speaks for itself- I hope.

Hey did you ever get this installed? If so how well does it work for you?

[idealer]

The guy on the forum after wasting my time for over a month disappointed me on the most important part which is the metal pipe. No problem though I am getting it all now brand new from the dealer and online. But it will have to wait till summer. It is too cold now and I have other commitments plus I have gotten used to it just the way it is. Infact the only reason I am going ahead with it is just to say I did it.

[Shawno72]

Originally Posted by idealer

The guy on the forum after wasting my time for over a month disappointed me on the most important part which is the metal pipe. No problem though I am getting it all now brand new from the dealer and online. But it will have to wait till summer. It is too cold now and I have other commitments plus I have gotten used to it just the way it is. Infact the only reason I am going ahead with it is just to say I did it.

Haha that's kinda why I asked. I got all the factory pieces for the piping except for the under the hood line. I just ordered that this morning. I also have gotten used to it and kinda like it now. I'm more wanting to do it for my neighbors

[idealer]

Well NPP will not save your neighbors because it will still be loud on startup. I thought there was some kind of drone at between 50MPH especially if you hold it steady at 50. That was why I was persistent on getting the complete system. However I am used to it now so it does not bother me much but I will still do the whole thing just because I said I will.

[Shawno72]

Originally Posted by idealer

Well NPP will not save your neighbors because it will still be loud on startup. I thought there was some kind of drone at between 50MPH especially if you hold it steady at 50. That was why I was persistent on getting the complete system. However I am used to it now so it does not bother me much but I will still do the whole thing just because I said I will.

Ok I thought that I read that it stayed open at startup. May as well just leave it, but like you said I have now gathered all the necessary parts to do it either the factory way or by this method

[4RSS FED]

Just wanted to throw out this tidbit. My car has gotten a few "evap" codes over the past few months. I believe it was the P0442 code. Everything looked normal, so the first time it happened, I replaced the gas cap thinking that was the problem. Then it showed up again a month later. Cleared the code. Then it showed up again a couple of weeks ago. Then I had a light bulb moment. I believe it is coming from my manual exhaust valve switch. I usually don't move it and run open all the time, but I had moved it a few times for demonstrations before the code showed. I believe there is a vacuum leak at the switch (or from the switch to the exhaust) that the computer can detect. So I need to look at it but wanted to share the info in case anyone else has had the same issue.

[forzasteve]

Originally Posted by 4RSS FED

Just wanted to throw out this tidbit. My car has gotten a few "evap" codes over the past few months. I believe it was the P0442 code. Everything looked normal, so the first time it happened, I replaced the gas cap thinking that was the problem. Then it showed up again a month later. Cleared the code. Then it showed up again a couple of weeks ago. Then I had a light bulb moment. I believe it is coming from my manual exhaust valve switch. I usually don't move it and run open all the time, but I had moved it a few times for demonstrations before the code showed. I believe there is a vacuum leak at the switch (or from the switch to the exhaust) that the computer can detect. So I need to look at it but wanted to share the info in case anyone else has had the same issue.

What kind of switch do you have that would contribute to a vacuum leak? Are you using a vacuum valve as the switch? If you are using an electric switch, then it merely is opening and closing the circuit that controls the vacuum solenoid valve. If you have the stock NPP exhaust, this should not contribute to a vacuum leak. But, if you do have a vacuum leak, check the vacuum line from the engine to the vacuum accumulator tank. Then check the vacuum accumulator tank itself. Lastly, the vacuum line from the engine to the accumulator tank should have a one-way check valve in-line with the tubing. This is prevent vacuum leaks downstream of the check valve. You may want to check that as well.

Steve

[4RSS FED]

Thanks Steve. It is a C3 Corvette manual headlight/wiper door vacuum override switch. Yes it is a valve with a plunger used to switch vacuum on or off. Non NPP production car.

From Post #1

[4RSS FED]

Well I think I was wrong about what I posted about the switch. I have been moving it in and out while driving the past two days and cannot duplicate the code. So please disregard my previous post #78. My light bulb is dim. If something changes I will follow up.

[olblue75]

Anyone need a set of dual mode mufflers off a 2012 ZL1 with 12-15k miles???

[Alessio]

Originally Posted by 4RSS FED

Thanks Steve. It is a C3 Corvette manual headlight/wiper door vacuum override switch. Yes it is a valve with a plunger used to switch vacuum on or off. Non NPP production car.

From Post #1

Hello, (Forgive my bad english)

Thank you for this very useful Thread, i'm about to receive my ZL1 used Mufflers, and i got as well a C3 Corvette Vacuum switch.
One question, few posts ago someone was talking about hissing noises probably related to a wrong port hook up on the switch (inverted).
Can you suggest me what port use as vacuum input and what to the mufflers on the switch? (white or blue) Thanks,

Alessio

[derek1387]

Anyone know of a good spot to connect up to the vac system on a V6? Potentially the blocked off port on the rear of the manifold that I blocked off for my clean side separator?