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-   -   npp exhaust (https://www.corvetteforum.com/forums/c6-corvette-general-discussion/1761784-npp-exhaust.html)

Bryanwithy 07-19-2007 01:35 AM

npp exhaust
 
since i have heard such wonderful things about the npp, i was wondering, and this may be a completely stupid question from a newbie.

can the npp exhaust be installed on the LS2. i ordered my car before finding this wonderful resource and although i KNOW i will be happy with my little "old" LS2 i had this question.

:confused:

SunsetOrangeCreations 07-19-2007 01:57 AM

Here is link to the post about adding the z06 bi mode exhaust to a ls2.

http://forums.corvetteforum.com/show....php?t=1726443

I am in the process of doing it.

I didnt want to buy an 08 for the exhaust so I'm putting in 3" Z06 exhaust instead! Ha.

BTW the zo6 mufflers are 2.5" inlet. The Zo6 pipes neck down to 2.5 into the mufflers.
Gm just reused the same mufflers and used 2.5" pipe from the cats to the mufflers on the 08 ls3 npp system.

I am using a corsa 2.5" to 3" x-pipe to mate the ls2 cats to the z06 mufflers. I am using all gm vacuum tubing so no fab work is needed.
The valves will need a manual switch or a NPP / Z06 Exhaust Commander switch to operate like a stock z06 or NPP but that is not too difficult.

Good Luck on the install! :cheers:

NORTY 07-19-2007 02:01 AM


Originally Posted by Bryanwithy (Post 1561136257)
since i have heard such wonderful things about the npp, i was wondering, and this may be a completely stupid question from a newbie.

No such thing as a "stupid question" only an unanswered one.


can the npp exhaust be installed on the LS2. i ordered my car before finding this wonderful resource and although i KNOW i will be happy with my little "old" LS2 i had this question.

:confused:
You would need to retrofit the LS3 electronics also. It would be a project for sure. Problematic probably also.
Now, if you acquired the NPP plumbing and installed a "mild to wild" switch, eliminating the electronics...

Be sure you hear the new system before to jump ahead with this. You may find better sound in the aftermarket. Since you're in Cali, don't forget about future smog testing.:eek:

talon90 07-19-2007 06:08 AM

Mechanically the NPP will bolt right on, no problem. The problem comes down to the operation of the butterfly valves. The exhaust takes its cue from the throttle position sensor and rpm gage. The NPP also operates on vacuum pressure to actuate the butterfly valve and you won't have the requisite vacuum storage or pressure lines to cause it to operate. At the end of the day, it will be an "always open system" until someone comes out with an aftermarket control strategy.

Paul :cheers:

hawkeyefan 07-19-2007 06:38 AM

I would suspect that it would be a very difficult task given one thread I recently read. It is a thread where a forum user just received their 2008 car but it was missing the NPP exhaust. It appeared that the dealership felt it was way too complicated adding NPP to a non-NPP car so they ordered them a new car instead.

robl45 07-19-2007 07:04 AM

I think that was more of an issue of they got a brand new car and didn't want it being manhandled by the dealership although I haven't read the whole thread. But seriously, some dolt will come along and point out that the npp wasn't original on the car and who wants to buy a new car and deal wtih that?


Originally Posted by hawkeyefan (Post 1561136963)
I would suspect that it would be a very difficult task given one thread I recently read. It is a thread where a forum user just received their 2008 car but it was missing the NPP exhaust. It appeared that the dealership felt it was way too complicated adding NPP to a non-NPP car so they ordered them a new car instead.


Pipedreams 07-19-2007 07:09 AM


Originally Posted by talon90 (Post 1561136878)
The NPP also operates on vacuum pressure to actuate the butterfly valve and you won't have the requisite vacuum storage or pressure lines to cause it to operate. At the end of the day, it will be an "always open system" until someone comes out with an aftermarket control strategy.

Paul :cheers:

I am working on something to make this happen :thumbs:

ben dover 07-19-2007 07:34 AM


Originally Posted by Pipedreams (Post 1561137102)
I am working on something to make this happen :thumbs:

There you go - Ed's the man.

talon90 07-19-2007 08:22 AM


Originally Posted by Pipedreams (Post 1561137102)
I am working on something to make this happen :thumbs:

:yesnod: :thumbs: I didn't want to give away the secret. ;)

talon90 07-19-2007 08:22 AM


Originally Posted by ben dover (Post 1561137240)
There you go - Ed's the man.

:iagree: :thumbs: :thumbs: :cheers:

jschindler 07-19-2007 09:44 AM

It can be installed on an older car if you don't mind operating it manually. I have a friend who has done it, and I watched him open and close it - so I know it can be done.

Wayne O 07-19-2007 09:46 AM

Anything's an improvement over the weak, stock C6 exhaust but IMO you can do better than the NPP exhaust. IMO unless you just like the sound of the NPP exhaust (compared to other systems) I'd find an after-market exhaust you like and go with that....have your Corvette sound 'good' all the time...not part time. I'd hardly worry about an after-market exhaust negatively affecting resale value.

ohmy 07-19-2007 09:58 AM


Originally Posted by Wayne O (Post 1561138597)
Anything's an improvement over the weak, stock C6 exhaust but IMO you can do better than the NPP exhaust. IMO unless you just like the sound of the NPP exhaust (compared to other systems) I'd find an after-market exhaust you like and go with that....have your Corvette sound 'good' all the time...not part time. I'd hardly worry about an after-market exhaust negatively affecting resale value.

:iagree:

Ken Erickson 07-19-2007 10:11 AM

For those of us that like to stay on the good side of our neighbors the NPP (or any A/M bimodal exhaust systems) makes sense when it comes to changing the Corvette sound. I just don’t want to hear my neighbor pounding on my door complaining about my waking them up at O dark thirty every morning while leaving for work.

jschindler 07-19-2007 10:29 AM


Originally Posted by Wayne O (Post 1561138597)
Anything's an improvement over the weak, stock C6 exhaust but IMO you can do better than the NPP exhaust. IMO unless you just like the sound of the NPP exhaust (compared to other systems) I'd find an after-market exhaust you like and go with that....have your Corvette sound 'good' all the time...not part time. I'd hardly worry about an after-market exhaust negatively affecting resale value.

Wayne, have you spent any time driving an 08 with the NPP? I have. And I've had three Corvettes with B&B Bullets (and one with B&B PRTs). I've heard most of the other aftermarket exhausts as well. The NPP sounds as good as any of them, in my opinion. And you CAN have the sound all the time. For about $18, I put a switch in my circuit. I have have the good sound all the time, and turn it to quiet for those times I don't want it louder.

GM hit a grand slam with this option. From the posts I've seen, most of the people voting against it have never driven one. I've now got about 1200 miles on my car - about 900 with the exhausts open all the time. To me, there are absolutely no negatives to this system - only positives.

ohmy 07-19-2007 10:52 AM


Originally Posted by jschindler (Post 1561139153)
Wayne, have you spent any time driving an 08 with the NPP? I have. And I've had three Corvettes with B&B Bullets (and one with B&B PRTs). I've heard most of the other aftermarket exhausts as well. The NPP sounds as good as any of them, in my opinion. And you CAN have the sound all the time. For about $18, I put a switch in my circuit. I have have the good sound all the time, and turn it to quiet for those times I don't want it louder.

GM hit a grand slam with this option. From the posts I've seen, most of the people voting against it have never driven one. I've now got about 1200 miles on my car - about 900 with the exhausts open all the time. To me, there are absolutely no negatives to this system - only positives.

I can't say that I have had the fortune to own as many Vettes as you have, but I did my fair share of research by listening to other owners Vettes at car shows and gatherings, I also got a chance to listen to an NPP exhaust at a semi-local dealership last week (for those of you in the central Jersey location, Oasis chevrolet).

With that said, I can say without any doubt or reservations, that the NPP sound doesnt even come close to the Borlas!!! The NPP sounds like a sick Corsa with thin walls. I can't believe anyone would like them. Grand Slam for GM - HA!!! Its more like a foul ball that went over the wall and hit an old lady in the head!!!

Anyway, in the end it's just personal opinion, yours is as good as mine, but I can tell you that NPP will never be found on my Vette...

BTW, for those folks that are concerned about your neighbors - stick with the base exhaust for your Vette - I found that the NPP is very loud at start up, just as loud as aftermarket exhaust. Also, when pulling into your driveway, aftermarket exhaust is no louder...

jschindler 07-19-2007 10:57 AM


Originally Posted by ohmy (Post 1561139457)
I can't say that I have had the fortune to own as many Vettes as you have, but I did my fair share of research by listening to other owners Vettes at car shows and gatherings, I also got a chance to listen to an NPP exhaust at a semi-local dealership last week (for those of you in the central Jersey location, Oasis chevrolet).

With that said, I can say without any doubt or reservations, that the NPP sound doesnt even come close to the Borlas!!! The NPP sounds like a sick Corsa with thin walls. I can't believe anyone would like them. Grand Slam for GM - HA!!! Its more like a foul ball that went over the wall and hit an old lady in the head!!!

Anyway, in the end it's just personal opinion, yours is as good as mine, but I can tell you that NPP will never be found on my Vette...

Did you ride in the cars, or just listen to them standing still? While I agree that it is all subjective, I've ridden in two different C6's with Corsa Sports. One of them I rode in for about three hours -much of it very spirited driving. I can assure you that the NPP sounds much deeper than they do. These are very close to the Bullets I had just. I also suspect you did not listen to the NPP's with the fuse pulled.

If you feel you have heard them enough to make a fair comparison, I will say that yes, it's subjective and I would not tell you or anyone else is wrong. Just be sure to give them a fair chance before ruling them out. I can tell you that based on my rides in cars with Corsas that I have always considered them a total waste of money - I hope that gives you an idea of where I'm coming from.

ohmy 07-19-2007 02:53 PM


Originally Posted by jschindler (Post 1561139503)
Did you ride in the cars, or just listen to them standing still? While I agree that it is all subjective, I've ridden in two different C6's with Corsa Sports. One of them I rode in for about three hours -much of it very spirited driving. I can assure you that the NPP sounds much deeper than they do. These are very close to the Bullets I had just. I also suspect you did not listen to the NPP's with the fuse pulled.

If you feel you have heard them enough to make a fair comparison, I will say that yes, it's subjective and I would not tell you or anyone else is wrong. Just be sure to give them a fair chance before ruling them out. I can tell you that based on my rides in cars with Corsas that I have always considered them a total waste of money - I hope that gives you an idea of where I'm coming from.

I heard Borlas inside and outside the car, Corsas and NPP outside only. The Borlas to me are like the definition of what a car like this should sound like. I did not care for the Corsas and NPP - too raspy/tinny, not deep/mellow enough. But, I don't disagree with you that I should drive in the car to finalize my opinion, and I probably will do that. But with that said, and knowing that Borlas are a bit cheaper than NPP, very easy to install, look great, and sound absolutely incredible, I think my money is on the Borlas.

BTW, I hate the NPP split personality thing. I know that its a plus for many people, but I just see it as a gimmick that has no place on a sports car. And honestly, as far as the neighbors are concerned, NPP is NOT that quiet, like I said in my previous post, the start up is LOUD, so if people think that this will make their neighbors happy - think again...

talon90 07-19-2007 03:31 PM


Originally Posted by SunsetOrangeDream (Post 1561143611)
Its very easy to get the vacuum to work. I bought all the gm vacuum piping, electric vacuum solenoid and storage canister from a z06. Its all plug and play no fab needed, except to run a wire from the vac solenoid to the fuse panel in the passenger footwell.

Its just the rpm actuating of the valves that is harder to do. But not really that hard, I'm just using a MSD RPM Switch to open the circuit to the vac solenoid at a specifed RPM. So it opens at say 3000 rpm and the valves open, or hit the mild to wild switch and they are open all the time. There you go.... :thumbs:

In the end it works 90% the same as the z06 or NPP. Just not using the BCM signals for the valve operation so no comp mode and regular mode.

Nice job. Not something I would have attempted.

MThomas 07-19-2007 04:24 PM


Originally Posted by jschindler (Post 1561139153)
Wayne, have you spent any time driving an 08 with the NPP? I have. And I've had three Corvettes with B&B Bullets (and one with B&B PRTs). I've heard most of the other aftermarket exhausts as well. The NPP sounds as good as any of them, in my opinion. And you CAN have the sound all the time. For about $18, I put a switch in my circuit. I have have the good sound all the time, and turn it to quiet for those times I don't want it louder.

GM hit a grand slam with this option. From the posts I've seen, most of the people voting against it have never driven one. I've now got about 1200 miles on my car - about 900 with the exhausts open all the time. To me, there are absolutely no negatives to this system - only positives.

Jim......:iagree:


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