Z06 muffler question
02-09-2011, 06:53 PM
#41
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St. Jude Donor '11-'12-'13, '16-'17-'18
From what I understand, yes.
Here are the internals of an unmodified Z06 muffler...
NPP mufflers look like this EXCEPT there are no holes in that crossover pipe you see in the picture above. The "Z06 muffler mod" is simply making the pipe with all the holes in it a solid pipe (usually by covering it with clamps or another section of pipe).
Here are the internals of an unmodified Z06 muffler...
NPP mufflers look like this EXCEPT there are no holes in that crossover pipe you see in the picture above. The "Z06 muffler mod" is simply making the pipe with all the holes in it a solid pipe (usually by covering it with clamps or another section of pipe).
02-09-2011, 07:18 PM
#42
Drifting
Spin,
The 3 inch "mating pipes" you refer to, are they the stock Z06 mid pipe and the pipes attached to the mufflers, is that correct?
Questions please:
Do some Z06's have an H-pipe, and others have an X-pipe? ...and if so, does it make a hill of beans difference in power which one, an X-pipe or a H-pipe, is used ???
What are the pro's and con's of installing the complete Z06 exhaust from the front all the way to rear on a completely stock C6 ?? - Meaning does installing Z06 complete exhaust system on a stock C6 have any negative effects of less bottom end, or anything else, etc, etc, on a stock C6?
Lastly, how will the stock Z06 exhaust sound on a stock C6 compared to the NPP that's optional on the C6 now? - I think I understand that the NPP mufflers are louder, plus they sound kind of "burbbly" and raspy when open.
Do the unmodified Z06 mufflers sound as "rough" and raspy? And how much quieter are the stock unmodified Z06 mufflers than the C6 NPP mufflers??? Are the NPP louder than Z06 all the time, or just when wide open?
.
The 3 inch "mating pipes" you refer to, are they the stock Z06 mid pipe and the pipes attached to the mufflers, is that correct?
Questions please:
Do some Z06's have an H-pipe, and others have an X-pipe? ...and if so, does it make a hill of beans difference in power which one, an X-pipe or a H-pipe, is used ???
What are the pro's and con's of installing the complete Z06 exhaust from the front all the way to rear on a completely stock C6 ?? - Meaning does installing Z06 complete exhaust system on a stock C6 have any negative effects of less bottom end, or anything else, etc, etc, on a stock C6?
Lastly, how will the stock Z06 exhaust sound on a stock C6 compared to the NPP that's optional on the C6 now? - I think I understand that the NPP mufflers are louder, plus they sound kind of "burbbly" and raspy when open.
Do the unmodified Z06 mufflers sound as "rough" and raspy? And how much quieter are the stock unmodified Z06 mufflers than the C6 NPP mufflers??? Are the NPP louder than Z06 all the time, or just when wide open?
.
Last edited by Silverado Desperado; 02-09-2011 at 07:22 PM.
02-09-2011, 08:13 PM
#43
Tech Contributor
Thread Starter
You dont use the Z06 midpipes. Nothing other than the axle-back Z06 mufflers are used when you get Z06 headers.
I cant answer your other questions because I dont have nor did I ever have a stock Z06 exhaust system from the exhaust manifolds up to the axle back.
02-09-2011, 08:17 PM
#44
Tech Contributor
Thread Starter
You dont have to cut up the Z06 mufflers to have good sound. I prefer the stock Z06 mufflers to the NPP. I think it hurts potential buyers when someone gives an opinion making others think the Z06 exhaust is inferior when on a high power car it makes more power.
02-09-2011, 08:24 PM
#45
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"Lastly, how will the stock Z06 exhaust sound on a stock C6 compared to the NPP that's optional on the C6 now? - I think I understand that the NPP mufflers are louder, plus they sound kind of "burbbly" and raspy when open.
Do the unmodified Z06 mufflers sound as "rough" and raspy? And how much quieter are the stock unmodified Z06 mufflers than the C6 NPP mufflers??? Are the NPP louder than Z06 all the time, or just when wide open? "
--------------------
I put Z06 mufflers on my 06 not long after I bought it. Some people have said I'm wrong, but I was there and watched the muffler shop install them and after we cut off the old mufflers, the Z06 mufflers were welded into place and the pipe sizes were exactly the same. It was fairly easy and the Z06 mufflers cost $300 at the time.
My friend has an 08 and at idle his NPP mufflers are louder than mine. I haven't heard mine when the car is taking off but I have heard his and there is a kind of raspy, but good, sound. When closed, my mufflers are as quiet as the car was when stock. I'm not sure how quiet his NPP's are when closed but I seem to recall his saying once that mine were quieter when closed than his were.
I hope this gives a little personal perspective.
Do the unmodified Z06 mufflers sound as "rough" and raspy? And how much quieter are the stock unmodified Z06 mufflers than the C6 NPP mufflers??? Are the NPP louder than Z06 all the time, or just when wide open? "
--------------------
I put Z06 mufflers on my 06 not long after I bought it. Some people have said I'm wrong, but I was there and watched the muffler shop install them and after we cut off the old mufflers, the Z06 mufflers were welded into place and the pipe sizes were exactly the same. It was fairly easy and the Z06 mufflers cost $300 at the time.
My friend has an 08 and at idle his NPP mufflers are louder than mine. I haven't heard mine when the car is taking off but I have heard his and there is a kind of raspy, but good, sound. When closed, my mufflers are as quiet as the car was when stock. I'm not sure how quiet his NPP's are when closed but I seem to recall his saying once that mine were quieter when closed than his were.
I hope this gives a little personal perspective.
02-09-2011, 08:29 PM
#46
Drifting
Are the stock unmodified Z06 mufflers somewhat quiter than the NPP mufflers? - I think I understand that the NPP mufflers are louder, plus they sound kind of "burbbly" and raspy when open. Is that correct?
Do the unmodified Z06 mufflers sound not as "rough" and raspy as the NPP mufflers?
Are the unmodified Z06 mufflers deeper sounding and slightly quieter than the C6 NPP mufflers???
.
(Thanks for the perspective. Sorry, I type so slow, I was typing when you posted.)
.
Do the unmodified Z06 mufflers sound not as "rough" and raspy as the NPP mufflers?
Are the unmodified Z06 mufflers deeper sounding and slightly quieter than the C6 NPP mufflers???
.
(Thanks for the perspective. Sorry, I type so slow, I was typing when you posted.)
.
Last edited by Silverado Desperado; 02-09-2011 at 08:33 PM.
02-09-2011, 08:45 PM
#47
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St. Jude Donor '17
I guess I should feel honored that I am keeping this "Rumor" alive. From you original post you made it sound as if it was the same job to install a 3" system verses just adding NPP to which I responded.
Maybe I some how misunderstood your intent that adding headers and a different X pipe to the stock Bi-Mode Z06 mufflers was cheaper and just as easy as NPP. My bad I guess.
Maybe I some how misunderstood your intent that adding headers and a different X pipe to the stock Bi-Mode Z06 mufflers was cheaper and just as easy as NPP. My bad I guess.
Your post is exactly why this myth is around. The Z06 mufflers are 100% bolt-on and go on your car in your garage with no muffler shop. When you buy headers, you buy them for the Z06 with the end pipes being the only difference. They bolt up to the Z06 axle back pipes with no welding and they install exactly the same as a 2.5" system on a header set that comes down to 2.5 inches on those rear pipes.
They are not labor intensive and are on my car now having installed them myself in my garage.
Sound is subjective. Everyone who goes in my car likes the sound including corsa and borla owners.
The ability to close the flaps and have quiet is priceless.
They are not labor intensive and are on my car now having installed them myself in my garage.
Sound is subjective. Everyone who goes in my car likes the sound including corsa and borla owners.
The ability to close the flaps and have quiet is priceless.
02-09-2011, 08:58 PM
#48
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When I bought LG pro headers for my C6 they asked me if I wanted 3" or 2 1/2" connecter pipes. It all depends on which axle back system you've got. Also when you do the muffler mod on a Z-06 bi mode set of mufflers they sound exactly like the NPPs, I've heard both of them.
02-10-2011, 01:27 AM
#49
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If this discussion was purely about sound or cost, like some responses indicate, I wouldn't bother posting, because that's opinion. The part about power is factual information that can be measured.
Looking back to '06, GM designed the Z06 mufflers to match the engine exhaust output. Standard C6 owners then started putting them on their cars primarily for the dual sounds. GM saw an opportunity to make extra money and created the NPP muffler by eliminating the perforated internal pipe and perforating the tips. Of course, they retained the rest of the system at the original 2.5" pipe size, especially over-the-axle to provide clearance for the A6. End of history lesson.
Now about the power vs. pipe size and the muffler mod.
Remembering the reason that the Z06 has the 3" pipe size is important. A nearly 14% increase in displacement over the LS3 and a HP rating 400 RPM higher require larger pipes. That was also a 17% difference on a LS2.
The 3" pipe has an area that is 46% larger than a 2.5" pipe. Considering that the dyno results for header installs on Z06 cars show far less gains than header installs on LS2/3 cars, then it's reasonable to see that the Z06 manifold/pipes are much more closely sized for the LS7 than the 2.5" system is on the LS2/3.
Using the complete Z06 manifolds/pipes/mufflers on the smaller engines is a case of going too big for too much distance. As the gasses cool, they lose velocity if the pipe size remains constant. To retain the initial velocity, the pipe size must be reduced. The Z06 with it's larger displacement and higher RPM creates more volume and therefore retains more heat at a higher velocity and doesn't require a pipe reduction until it reaches the muffler. The smaller and lower RPM LS2/3 needs to reduce pipe size well before the muffler to maintain velocity. The easiest location for the size reduction to be effected is just prior to the over-the-axle pipe.
Now lets talk mufflers. Both the Z06 and NPP mufflers share the same 2.5" inlet, primary (small) 2" and secondary (large) 2.375" outlet. Note that the primary (designed for less than 3500 RPM) is much smaller to help maintain velocity due to additional heat losses in the muffler and lower total volume. The secondary is essentially a muffler bypass to provide higher volume relief. Doing a muffler mod on Z06 mufflers reduces the percentage of exhaust going out the primary outlet, but may increase velocity at WOT.
Looking back to '06, GM designed the Z06 mufflers to match the engine exhaust output. Standard C6 owners then started putting them on their cars primarily for the dual sounds. GM saw an opportunity to make extra money and created the NPP muffler by eliminating the perforated internal pipe and perforating the tips. Of course, they retained the rest of the system at the original 2.5" pipe size, especially over-the-axle to provide clearance for the A6. End of history lesson.
Now about the power vs. pipe size and the muffler mod.
Remembering the reason that the Z06 has the 3" pipe size is important. A nearly 14% increase in displacement over the LS3 and a HP rating 400 RPM higher require larger pipes. That was also a 17% difference on a LS2.
The 3" pipe has an area that is 46% larger than a 2.5" pipe. Considering that the dyno results for header installs on Z06 cars show far less gains than header installs on LS2/3 cars, then it's reasonable to see that the Z06 manifold/pipes are much more closely sized for the LS7 than the 2.5" system is on the LS2/3.
Using the complete Z06 manifolds/pipes/mufflers on the smaller engines is a case of going too big for too much distance. As the gasses cool, they lose velocity if the pipe size remains constant. To retain the initial velocity, the pipe size must be reduced. The Z06 with it's larger displacement and higher RPM creates more volume and therefore retains more heat at a higher velocity and doesn't require a pipe reduction until it reaches the muffler. The smaller and lower RPM LS2/3 needs to reduce pipe size well before the muffler to maintain velocity. The easiest location for the size reduction to be effected is just prior to the over-the-axle pipe.
Now lets talk mufflers. Both the Z06 and NPP mufflers share the same 2.5" inlet, primary (small) 2" and secondary (large) 2.375" outlet. Note that the primary (designed for less than 3500 RPM) is much smaller to help maintain velocity due to additional heat losses in the muffler and lower total volume. The secondary is essentially a muffler bypass to provide higher volume relief. Doing a muffler mod on Z06 mufflers reduces the percentage of exhaust going out the primary outlet, but may increase velocity at WOT.
02-10-2011, 02:12 AM
#50
Drifting
Good clear explanation!
Thanks!
If this discussion was purely about sound or cost, like some responses indicate, I wouldn't bother posting, because that's opinion. The part about power is factual information that can be measured.
Looking back to '06, GM designed the Z06 mufflers to match the engine exhaust output. Standard C6 owners then started putting them on their cars primarily for the dual sounds. GM saw an opportunity to make extra money and created the NPP muffler by eliminating the perforated internal pipe and perforating the tips. Of course, they retained the rest of the system at the original 2.5" pipe size, especially over-the-axle to provide clearance for the A6. End of history lesson.
Now about the power vs. pipe size and the muffler mod.
Remembering the reason that the Z06 has the 3" pipe size is important. A nearly 14% increase in displacement over the LS3 and a HP rating 400 RPM higher require larger pipes. That was also a 17% difference on a LS2.
The 3" pipe has an area that is 46% larger than a 2.5" pipe. Considering that the dyno results for header installs on Z06 cars show far less gains than header installs on LS2/3 cars, then it's reasonable to see that the Z06 manifold/pipes are much more closely sized for the LS7 than the 2.5" system is on the LS2/3.
Using the complete Z06 manifolds/pipes/mufflers on the smaller engines is a case of going too big for too much distance. As the gasses cool, they lose velocity if the pipe size remains constant. To retain the initial velocity, the pipe size must be reduced. The Z06 with it's larger displacement and higher RPM creates more volume and therefore retains more heat at a higher velocity and doesn't require a pipe reduction until it reaches the muffler. The smaller and lower RPM LS2/3 needs to reduce pipe size well before the muffler to maintain velocity. The easiest location for the size reduction to be effected is just prior to the over-the-axle pipe.
Now lets talk mufflers. Both the Z06 and NPP mufflers share the same 2.5" inlet, primary (small) 2" and secondary (large) 2.375" outlet. Note that the primary (designed for less than 3500 RPM) is much smaller to help maintain velocity due to additional heat losses in the muffler and lower total volume. The secondary is essentially a muffler bypass to provide higher volume relief. Doing a muffler mod on Z06 mufflers reduces the percentage of exhaust going out the primary outlet, but may increase velocity at WOT.
Thanks!
If this discussion was purely about sound or cost, like some responses indicate, I wouldn't bother posting, because that's opinion. The part about power is factual information that can be measured.
Looking back to '06, GM designed the Z06 mufflers to match the engine exhaust output. Standard C6 owners then started putting them on their cars primarily for the dual sounds. GM saw an opportunity to make extra money and created the NPP muffler by eliminating the perforated internal pipe and perforating the tips. Of course, they retained the rest of the system at the original 2.5" pipe size, especially over-the-axle to provide clearance for the A6. End of history lesson.
Now about the power vs. pipe size and the muffler mod.
Remembering the reason that the Z06 has the 3" pipe size is important. A nearly 14% increase in displacement over the LS3 and a HP rating 400 RPM higher require larger pipes. That was also a 17% difference on a LS2.
The 3" pipe has an area that is 46% larger than a 2.5" pipe. Considering that the dyno results for header installs on Z06 cars show far less gains than header installs on LS2/3 cars, then it's reasonable to see that the Z06 manifold/pipes are much more closely sized for the LS7 than the 2.5" system is on the LS2/3.
Using the complete Z06 manifolds/pipes/mufflers on the smaller engines is a case of going too big for too much distance. As the gasses cool, they lose velocity if the pipe size remains constant. To retain the initial velocity, the pipe size must be reduced. The Z06 with it's larger displacement and higher RPM creates more volume and therefore retains more heat at a higher velocity and doesn't require a pipe reduction until it reaches the muffler. The smaller and lower RPM LS2/3 needs to reduce pipe size well before the muffler to maintain velocity. The easiest location for the size reduction to be effected is just prior to the over-the-axle pipe.
Now lets talk mufflers. Both the Z06 and NPP mufflers share the same 2.5" inlet, primary (small) 2" and secondary (large) 2.375" outlet. Note that the primary (designed for less than 3500 RPM) is much smaller to help maintain velocity due to additional heat losses in the muffler and lower total volume. The secondary is essentially a muffler bypass to provide higher volume relief. Doing a muffler mod on Z06 mufflers reduces the percentage of exhaust going out the primary outlet, but may increase velocity at WOT.
02-10-2011, 02:16 AM
#51
Drifting
I'm not real crazy about how the NPP mufflers sound when open going slow, or when open going fast. NPP's sound kind of like a truck with the muffler loose, "bloop, bloop, bloop" at idle, and rough and raspy when at higher rpms.
Do the Z06 mufflers sound deeper and not as rough and raspy?
Do the Z06 mufflers sound deeper and not as rough and raspy?
02-10-2011, 04:40 AM
#52
Tech Contributor
Thread Starter
I'm not real crazy about how the NPP mufflers sound when open going slow, or when open going fast. NPP's sound kind of like a truck with the muffler loose, "bloop, bloop, bloop" at idle, and rough and raspy when at higher rpms.
Do the Z06 mufflers sound deeper and not as rough and raspy?
Do the Z06 mufflers sound deeper and not as rough and raspy?
Nick at AR told me to stay with the 3" Z06 system when I was buying the new headers. If I was going to use a 2.5" system it would be a non-Z06 headers system he would send. Sorry but 3" up to the muffler inlet is better than 2.5" from the X-pipe to the muffler inlet. If it wasnt true then a 2.5" x-piep wouldnt be making less power than a 3" x-pipe.
Yes the NPP has a higher pitch like a corsa. I would define my car as raspy. I wouldnt want more. Personally, I associate low rumble with more power than high pitch.
02-10-2011, 09:36 AM
#54
Drifting
HOXXOH or Spin,
Will using the complete Z06 manifolds/pipes/mufflers on a stock LS3/2 be detrimental to the desired effect of better driveability, improved throttle response, and more hp? Will it lose bottom end? Will it need to rev higher to get in the powerband?
What will be the pro's and con's of installing the complete Z06 manifolds/pipes/mufflers on a stock LS3/2 ?
.
Last edited by Silverado Desperado; 02-10-2011 at 09:38 AM.
02-10-2011, 11:59 AM
#55
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What is the end result of the above????
HOXXOH or Spin,
Will using the complete Z06 manifolds/pipes/mufflers on a stock LS3/2 be detrimental to the desired effect of better driveability, improved throttle response, and more hp? Will it lose bottom end? Will it need to rev higher to get in the powerband?
What will be the pro's and con's of installing the complete Z06 manifolds/pipes/mufflers on a stock LS3/2 ?.
HOXXOH or Spin,
Will using the complete Z06 manifolds/pipes/mufflers on a stock LS3/2 be detrimental to the desired effect of better driveability, improved throttle response, and more hp? Will it lose bottom end? Will it need to rev higher to get in the powerband?
What will be the pro's and con's of installing the complete Z06 manifolds/pipes/mufflers on a stock LS3/2 ?.
The complete system (3" all the way) will work to the benefit of nearly all aspects under roughly 4000 RPM. From that point to redline, the full 3" is good, but not quite as efficient as the gradually reduced size piping. The other downside to the 3" is the extremely tight fit over-the-axle on an A6. It can be done, but it's prone to rattle. Reducing the pipe size prior to the axle solves that problem.
If the LS2/3 is highly modded (stroked, cam, FI, etc.) it will also be equipped with headers to accommodate the increased volume and the pipe size will need to adjust to match.
Spin has more than simple bolt-ons, so his needs are different.
02-10-2011, 12:09 PM
#56
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One more item I failed to mention, is the fit on '09 and up cars.
Because of the change in pipe configuration, it's much simpler to use the original 2.5" over-the-axle pipe mated to the Z06 muffler even if the rest of the system remains stock.
Because of the change in pipe configuration, it's much simpler to use the original 2.5" over-the-axle pipe mated to the Z06 muffler even if the rest of the system remains stock.
02-12-2011, 09:09 PM
#58
Melting Slicks
When I did the muffler mod on my Z06 mufflers, I used a 3" pipe and had to split it and cut out quite a bit. They are around 2.5" I.D. all the way through the muffler, O.D. is almost 2.75". (perforated section)
I also agree that the modded mufflers sound just like the NPP, and with the full Z06 exhaust, above 4K they sound even better.
DJ
I also agree that the modded mufflers sound just like the NPP, and with the full Z06 exhaust, above 4K they sound even better.
DJ
02-13-2011, 10:58 AM
#59
Drifting
02-13-2011, 11:25 AM
#60
Team Owner
I recently bought a pair of NPP mufflers that are waiting to be installed. Z06 mufflers would have been less expensive, but they would also require the Z06 Muffler Mod to sound like the NPPs. I don't have a welder and it just seemed like a pain to mess with the Z06 stuff when the NPP is a true bolt-on installation with no other worries.
I only care about the sound and not the extra 3 HP I might pick up by swapping the entire exhuast out.
I will agree that for someone on a budget, you can probably buy a complete front-to-back Z06 exhaust for less than what some guys are asking for a pair of NPPs.
pipe like the Z06 mufflers. I have ARH Z-06 headers and the Z catback fits perfect. Ok if your not running headers. Not for Z-06's!