Base Non-NPP Mufflers & FI
08-27-2014, 01:59 PM
#1
Drifting
Thread Starter
Base Non-NPP Mufflers & FI
Are they bad for an LS3 with ECS kit, cam, headers and o/r x pipe? I currently have '11 ZR1 NPPs and those things scream at wot!
I don't have the blower installed yet, but I'm concerned that the loudness and attention might be too much. At the same time I am also thinking if the non npp will hurt me bad power wise. I've seen people make over 600rwhp with them.
What do you think? Any suggestions? I heard the regular npps aren't near as loud since they have the perforated tube on the high side.
Thanks.
I don't have the blower installed yet, but I'm concerned that the loudness and attention might be too much. At the same time I am also thinking if the non npp will hurt me bad power wise. I've seen people make over 600rwhp with them.
What do you think? Any suggestions? I heard the regular npps aren't near as loud since they have the perforated tube on the high side.
Thanks.
08-27-2014, 02:25 PM
#2
Melting Slicks
Hmmm....I was thinking of swapping to the ZR1 NPP's. I have the base NPP on a ECS blower car...614 to the wheels through the base NPPs here.
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Want to trade!?!
08-27-2014, 02:53 PM
#3
Drifting
Thread Starter
08-27-2014, 03:32 PM
#4
Melting Slicks
08-27-2014, 03:41 PM
#5
Drifting
Thread Starter
I know you are at 1300+rwhp now, so I'm sure that you aren't using the base npp right now, correct?
08-27-2014, 03:52 PM
#6
Melting Slicks
im not a fan of the base mufflers.. i would keep base NPP and just leave it closed when cruising. from what i have seen the base exhaust is very restrictive
08-27-2014, 04:15 PM
#7
Drifting
Thread Starter
i moved to the Z06 npp.. just because my base NPP mufflers were literealy beat to death with a hammer before to make my LG sway bars fit lol...
im not a fan of the base mufflers.. i would keep base NPP and just leave it closed when cruising. from what i have seen the base exhaust is very restrictive
im not a fan of the base mufflers.. i would keep base NPP and just leave it closed when cruising. from what i have seen the base exhaust is very restrictive
08-27-2014, 07:15 PM
#8
Le Mans Master
Just to clarifly, folks do the "muffler mod" to Z06 mufflers to make them as loud as NPP mufflers. NPP is the option code for the optional bi mode mufflers available on Non Z06 and ZR1 Vettes. Z06 and ZR1's come stock with their own version of bi mode mufflers. They don't come with NPP's.
08-27-2014, 11:45 PM
#9
Melting Slicks
Member Since: Mar 2007
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Yep to ^ that.
Just to go a little more in depth, I've had all three styles of bi-mode C6 exhaust. Loudness wise, the ZR1 and regular C6 NPP mufflers are about the same. Both have the "solid" loud side piping. The real difference is that Zr1 mufflers are 3" where they connect to the x-pipe and they won't fit an x-pipe designed for 2.5" mufflers. The ZR1 and Z06 mufflers both neck down to 2.5" before entering the muffler.
The early Z06 cans are the quiet ones. They'd be what I'd look into if yuk want something quieter than the ZR1 style. That and they're cheap used.
For what it's worth, I thought my ZR1 mufflers sounded the best of the three. Just the best tone, in my opinion.
Just to go a little more in depth, I've had all three styles of bi-mode C6 exhaust. Loudness wise, the ZR1 and regular C6 NPP mufflers are about the same. Both have the "solid" loud side piping. The real difference is that Zr1 mufflers are 3" where they connect to the x-pipe and they won't fit an x-pipe designed for 2.5" mufflers. The ZR1 and Z06 mufflers both neck down to 2.5" before entering the muffler.
The early Z06 cans are the quiet ones. They'd be what I'd look into if yuk want something quieter than the ZR1 style. That and they're cheap used.
For what it's worth, I thought my ZR1 mufflers sounded the best of the three. Just the best tone, in my opinion.
08-28-2014, 05:32 AM
#10
Drifting
Thread Starter
Just to clarifly, folks do the "muffler mod" to Z06 mufflers to make them as loud as NPP mufflers. NPP is the option code for the optional bi mode mufflers available on Non Z06 and ZR1 Vettes. Z06 and ZR1's come stock with their own version of bi mode mufflers. They don't come with NPP's.
Yep to ^ that.
Just to go a little more in depth, I've had all three styles of bi-mode C6 exhaust. Loudness wise, the ZR1 and regular C6 NPP mufflers are about the same. Both have the "solid" loud side piping. The real difference is that Zr1 mufflers are 3" where they connect to the x-pipe and they won't fit an x-pipe designed for 2.5" mufflers. The ZR1 and Z06 mufflers both neck down to 2.5" before entering the muffler.
The early Z06 cans are the quiet ones. They'd be what I'd look into if yuk want something quieter than the ZR1 style. That and they're cheap used.
For what it's worth, I thought my ZR1 mufflers sounded the best of the three. Just the best tone, in my opinion.
Just to go a little more in depth, I've had all three styles of bi-mode C6 exhaust. Loudness wise, the ZR1 and regular C6 NPP mufflers are about the same. Both have the "solid" loud side piping. The real difference is that Zr1 mufflers are 3" where they connect to the x-pipe and they won't fit an x-pipe designed for 2.5" mufflers. The ZR1 and Z06 mufflers both neck down to 2.5" before entering the muffler.
The early Z06 cans are the quiet ones. They'd be what I'd look into if yuk want something quieter than the ZR1 style. That and they're cheap used.
For what it's worth, I thought my ZR1 mufflers sounded the best of the three. Just the best tone, in my opinion.
I would still like to know if there are others that have any personal experience using the non-npp with forced induction.
08-28-2014, 10:40 AM
#11
Melting Slicks
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Thank you very much for the clarification. I thought I had it right, but I'm obviously wrong. I'm either going to have to forget about the power loss with the base non-npp mufflers or move to the early z06 or get something different.
I would still like to know if there are others that have any personal experience using the non-npp with forced induction.
I would still like to know if there are others that have any personal experience using the non-npp with forced induction.
I'd personally think the base C6 mufflers would be a restriction. That's something I wouldn't even try running.
If you want to swap to pre-2011 Z06 mufflers, you're going to have to change the X-pipe, or at least the rear connecting pipes if they're replaceable on their own. But otherwise, they're a cheap option and support good power from what I've seen. I actually have a set of "muffler modded" Z06 cans sitting behind me as I type this. I have no need for them.
For what it's worth, you can do a bi-mode exhaust and keep it closed all the time if you really want. It sounds like you don't have a factory NPP car, so you'd have to retrofit a system, but those are easy to find. My '08 didn't come with NPP, so I used B&B's retrofit kit. It came with a vacuum reservoir and mild 2 wild remote control kit. Then I added a one-way check valve right at the intake manifold connection. That thing would hold vacuum for weeks at a time. I could have made a full mile WOT pull with the flaps shut if I'd wanted -- not that I ever wanted to do that.
With the ZR1 mufflers, it really was the best of both worlds. It was so quiet with the flaps closed that I rarely closed them, but it was nice to have the option.
08-28-2014, 12:57 PM
#12
Drifting
Thread Starter
I'd personally think the base C6 mufflers would be a restriction. That's something I wouldn't even try running.
If you want to swap to pre-2011 Z06 mufflers, you're going to have to change the X-pipe, or at least the rear connecting pipes if they're replaceable on their own. But otherwise, they're a cheap option and support good power from what I've seen. I actually have a set of "muffler modded" Z06 cans sitting behind me as I type this. I have no need for them.
For what it's worth, you can do a bi-mode exhaust and keep it closed all the time if you really want. It sounds like you don't have a factory NPP car, so you'd have to retrofit a system, but those are easy to find. My '08 didn't come with NPP, so I used B&B's retrofit kit. It came with a vacuum reservoir and mild 2 wild remote control kit. Then I added a one-way check valve right at the intake manifold connection. That thing would hold vacuum for weeks at a time. I could have made a full mile WOT pull with the flaps shut if I'd wanted -- not that I ever wanted to do that.
With the ZR1 mufflers, it really was the best of both worlds. It was so quiet with the flaps closed that I rarely closed them, but it was nice to have the option.
If you want to swap to pre-2011 Z06 mufflers, you're going to have to change the X-pipe, or at least the rear connecting pipes if they're replaceable on their own. But otherwise, they're a cheap option and support good power from what I've seen. I actually have a set of "muffler modded" Z06 cans sitting behind me as I type this. I have no need for them.
For what it's worth, you can do a bi-mode exhaust and keep it closed all the time if you really want. It sounds like you don't have a factory NPP car, so you'd have to retrofit a system, but those are easy to find. My '08 didn't come with NPP, so I used B&B's retrofit kit. It came with a vacuum reservoir and mild 2 wild remote control kit. Then I added a one-way check valve right at the intake manifold connection. That thing would hold vacuum for weeks at a time. I could have made a full mile WOT pull with the flaps shut if I'd wanted -- not that I ever wanted to do that.
With the ZR1 mufflers, it really was the best of both worlds. It was so quiet with the flaps closed that I rarely closed them, but it was nice to have the option.
08-28-2014, 10:22 PM
#13
Melting Slicks
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You are correct. My 08 didnt come with npp, so I ran a vacuum line from behind the intake and the flaps are normally closed during cruising and idle. I just consider the zr1s a little too loud for my taste and it does concerns me what is going to happen when boost come into the equation.
But I guess my point was that if you install a check-valve and a vacuum reservoir, you can keep the flaps closed at all times if you want. Not sure how good that would be for the mufflers at high rpm, but it's an option.
I love that I can control my exhaust with the DashLogic in the GS. I'm assuming the factory vacuum control system has a vacuum accumulator of some sort, because I can nail it and get into boost while the flaps stay shut. Most aftermarket "mild to wild" setups don't include a vacuum reservoir. B&B makes a nice setup that does.
08-29-2014, 10:59 AM
#15
Drifting
Thread Starter
08-29-2014, 11:09 AM
#16
Le Mans Master
I saw a 20 hp difference, flaps closed vs flaps open, on a 475hp cam only LS3. I do think the non NPP stockers would be better than the NPP's with the flaps closed. As per GM, the difference between stock mufflers and NPP's with the flaps open is a whoppin' 6 hp on a stock LS3.
08-29-2014, 02:43 PM
#17
Drifting
Thread Starter
I saw a 20 hp difference, flaps closed vs flaps open, on a 475hp cam only LS3. I do think the non NPP stockers would be better than the NPP's with the flaps closed. As per GM, the difference between stock mufflers and NPP's with the flaps open is a whoppin' 6 hp on a stock LS3.