Pics LT2 Engine
Racer
Joined: Aug 2011
Posts: 494
Likes: 138
From: Chesapeake, VA
That was indeed my point. It seems highly unlikely that GM would spend 100's of thousands of dollars to develop "Z51 only" tubular headers for exactly zero hp gain.
Given the stated HP numbers are the same for Z51 and non-Z51 w/NPP, I think it is far more likely that GM developed both the cast and the tubular headers, and then decided to use the tubular ones on *all* production C8 -- Z51 or not.
Less likely is the possibility that adding the NPP on the base car also adds the tubular headers. However the fact that the combo of headers and free flow exhaust still only gains 5hp -- seems weak. And since GM adopted SAE standards for HP measurement some years ago, that precludes the purposeful underrating of the HP numbers for insurance or any other reason.
Given the stated HP numbers are the same for Z51 and non-Z51 w/NPP, I think it is far more likely that GM developed both the cast and the tubular headers, and then decided to use the tubular ones on *all* production C8 -- Z51 or not.
Less likely is the possibility that adding the NPP on the base car also adds the tubular headers. However the fact that the combo of headers and free flow exhaust still only gains 5hp -- seems weak. And since GM adopted SAE standards for HP measurement some years ago, that precludes the purposeful underrating of the HP numbers for insurance or any other reason.
Melting Slicks
Joined: Aug 2004
Posts: 2,149
Likes: 1,349
From: Big D Dallas TEXAS
So, since the “Z51” and the “base non-Z51 with NPP” BOTH have exactly the same HP, that means the “Z51 only” tubular exhaust manifolds add exactly ZERO hp over cast manifolds?
That’s totally awesome and happens all the time.
Or, could it be that the info regarding “Z51-only” tubular exhaust is in error, and they actually exist on ALL C8?
Which scenario is more plausible?
That’s totally awesome and happens all the time.
Or, could it be that the info regarding “Z51-only” tubular exhaust is in error, and they actually exist on ALL C8?
Which scenario is more plausible?
PLEASE EVERYONE READ I am exhausted trying to help spread the truth on the forum. Exhausted lol funny.
From this engine article in ENGINELABS.Quote: The optional Z51 performance package delivers (among other desirable items) the four-into-one stainless steel equal length headers that no C8 should be ordered without. The standard iron manifolds will be of the 4-2-1 arrangement.
ARTICLE:
https://www.enginelabs.com/engine-te...but-different/
I know some on this forum have said this article is not correct about the C8 having two manifolds but I feel confident Jeffi is correct. His background is extensive and have followed him for a while.
From: Jeff Smith, a 35-year veteran of automotive journalism, comes to Power Automedia after serving as the senior technical editor at Car Craft magazine. An Iowa native, Smith served a variety of roles at Car Craft before moving to the senior editor role at Hot Rod and Chevy High Performance, and ultimately returning to Car Craft. An accomplished engine builder and technical expert, he will focus on the tech-heavy content that is the foundation of EngineLabs.
Last edited by fasttoys; Aug 9, 2019 at 12:13 AM.
Instructor
Joined: Feb 2013
Posts: 235
Likes: 37
From: Monterey CA
PLEASE EVERYONE READ I am exhausted trying to help spread the truth on the forum. Exhausted lol funny.
From this engine article in ENGINELABS.Quote: The optional Z51 performance package delivers (among other desirable items) the four-into-one stainless steel equal length headers that no C8 should be ordered without. The standard iron manifolds will be of the 4-2-1 arrangement.
ARTICLE:
https://www.enginelabs.com/engine-te...but-different/
From this engine article in ENGINELABS.Quote: The optional Z51 performance package delivers (among other desirable items) the four-into-one stainless steel equal length headers that no C8 should be ordered without. The standard iron manifolds will be of the 4-2-1 arrangement.
ARTICLE:
https://www.enginelabs.com/engine-te...but-different/
Race Director
Joined: Jun 2001
Posts: 10,084
Likes: 3,055
From: CA
PLEASE EVERYONE READ I am exhausted trying to help spread the truth on the forum. Exhausted lol funny.
From this engine article in ENGINELABS.Quote: The optional Z51 performance package delivers (among other desirable items) the four-into-one stainless steel equal length headers that no C8 should be ordered without. The standard iron manifolds will be of the 4-2-1 arrangement.
ARTICLE:
https://www.enginelabs.com/engine-te...but-different/
From this engine article in ENGINELABS.Quote: The optional Z51 performance package delivers (among other desirable items) the four-into-one stainless steel equal length headers that no C8 should be ordered without. The standard iron manifolds will be of the 4-2-1 arrangement.
ARTICLE:
https://www.enginelabs.com/engine-te...but-different/
Motor Trend said the Z51 came with six piston front calipers, too.
You can't always trust everything you read. At least, we now know at least one source of this ridiculous rumor.
Last edited by Michael A; Aug 9, 2019 at 12:11 AM.
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Melting Slicks
Joined: Aug 2004
Posts: 2,149
Likes: 1,349
From: Big D Dallas TEXAS
Maybe Engine Labs can show us a picture of these phantom cast iron manifolds, the ones no one has seen.
Motor Trend said the Z51 came with six piston front calipers, too.
You can't always trust everything you read. At least, we now know at least one source of this ridiculous rumor.
Motor Trend said the Z51 came with six piston front calipers, too.
You can't always trust everything you read. At least, we now know at least one source of this ridiculous rumor.
Ridiculous Rumors you mean many on the forums, FB, YT and other places, lol. Car & Driver has miss prints all the time, I stopped counting years ago.
I been telling people since 2016 the car was going to be below 70k and I was blasted multiple times. I try to get facts before I post anything on all the car forums I belong too, if I am wrong I change it or delete it. So I added the below comments and if I am wrong which I feel I am not based off other internal conversation about this motor it will be deleted or corrected ASAP. I been on a list for this car since 1/2016 and been a member of the forum since 04.
I know some on this forum have said this article is not correct about the C8 having two different manifolds but I feel confident Jeff is correct. His background is extensive and i have followed him for a long time.
From: Jeff Smith, a 35-year veteran of automotive journalism, comes to Power Automedia after serving as the senior technical editor at Car Craft magazine. An Iowa native, Smith served a variety of roles at Car Craft before moving to the senior editor role at Hot Rod and Chevy High Performance, and ultimately returning to Car Craft. An accomplished engine builder and technical expert, he will focus on the tech-heavy content that is the foundation of EngineLabs.
Last edited by fasttoys; Aug 9, 2019 at 12:37 AM.
Le Mans Master
Joined: Aug 2000
Posts: 6,486
Likes: 1,658
From: Las Vegas NV
PLEASE EVERYONE READ I am exhausted trying to help spread the truth on the forum. Exhausted lol funny.
From this engine article in ENGINELABS.Quote: The optional Z51 performance package delivers (among other desirable items) the four-into-one stainless steel equal length headers that no C8 should be ordered without. The standard iron manifolds will be of the 4-2-1 arrangement.
ARTICLE:
https://www.enginelabs.com/engine-te...but-different/
I know some on this forum have said this article is not correct about the C8 having two manifolds but I feel confident Jeffi is correct. His background is extensive and have followed him for a while.
From: Jeff Smith, a 35-year veteran of automotive journalism, comes to Power Automedia after serving as the senior technical editor at Car Craft magazine. An Iowa native, Smith served a variety of roles at Car Craft before moving to the senior editor role at Hot Rod and Chevy High Performance, and ultimately returning to Car Craft. An accomplished engine builder and technical expert, he will focus on the tech-heavy content that is the foundation of EngineLabs.
From this engine article in ENGINELABS.Quote: The optional Z51 performance package delivers (among other desirable items) the four-into-one stainless steel equal length headers that no C8 should be ordered without. The standard iron manifolds will be of the 4-2-1 arrangement.
ARTICLE:
https://www.enginelabs.com/engine-te...but-different/
I know some on this forum have said this article is not correct about the C8 having two manifolds but I feel confident Jeffi is correct. His background is extensive and have followed him for a while.
From: Jeff Smith, a 35-year veteran of automotive journalism, comes to Power Automedia after serving as the senior technical editor at Car Craft magazine. An Iowa native, Smith served a variety of roles at Car Craft before moving to the senior editor role at Hot Rod and Chevy High Performance, and ultimately returning to Car Craft. An accomplished engine builder and technical expert, he will focus on the tech-heavy content that is the foundation of EngineLabs.
I'll just mark you down as in the camp of those who think "GM spent a hundred thousand dollars to develop a Z51-ONLY set of headers that produce exactly zero HP gains over the cast manifolds that the non-Z51 will get, because...reasons"
Melting Slicks
Joined: Aug 2004
Posts: 2,149
Likes: 1,349
From: Big D Dallas TEXAS
Ok, so because you "feel" the article is correct, you are now 'exhausted' that not everyone agrees with your feeling?
I'll just mark you down as in the camp of those who think "GM spent a hundred thousand dollars to develop a Z51-ONLY set of headers that produce exactly zero HP gains over the cast manifolds that the non-Z51 will get, because...reasons"
I'll just mark you down as in the camp of those who think "GM spent a hundred thousand dollars to develop a Z51-ONLY set of headers that produce exactly zero HP gains over the cast manifolds that the non-Z51 will get, because...reasons"
Last edited by fasttoys; Aug 9, 2019 at 07:33 AM.
Race Director
Joined: Jun 2001
Posts: 10,084
Likes: 3,055
From: CA
I don't have a horse in the race.
Ridiculous Rumors you mean many on the forums, FB, YT and other places, lol. Car & Driver has miss prints all the time, I stopped counting years ago.
I been telling people since 2016 the car was going to be below 70k and I was blasted multiple times. I try to get facts before I post anything on all the car forums I belong too, if I am wrong I change it or delete it. So I added the below comments and if I am wrong which I feel I am not based off other internal conversation about this motor it will be deleted or corrected ASAP. I been on a list for this car since 1/2016 and been a member of the forum since 04.
I know some on this forum have said this article is not correct about the C8 having two different manifolds but I feel confident Jeff is correct. His background is extensive and i have followed him for a long time.
From: Jeff Smith, a 35-year veteran of automotive journalism, comes to Power Automedia after serving as the senior technical editor at Car Craft magazine. An Iowa native, Smith served a variety of roles at Car Craft before moving to the senior editor role at Hot Rod and Chevy High Performance, and ultimately returning to Car Craft. An accomplished engine builder and technical expert, he will focus on the tech-heavy content that is the foundation of EngineLabs.
Ridiculous Rumors you mean many on the forums, FB, YT and other places, lol. Car & Driver has miss prints all the time, I stopped counting years ago.
I been telling people since 2016 the car was going to be below 70k and I was blasted multiple times. I try to get facts before I post anything on all the car forums I belong too, if I am wrong I change it or delete it. So I added the below comments and if I am wrong which I feel I am not based off other internal conversation about this motor it will be deleted or corrected ASAP. I been on a list for this car since 1/2016 and been a member of the forum since 04.
I know some on this forum have said this article is not correct about the C8 having two different manifolds but I feel confident Jeff is correct. His background is extensive and i have followed him for a long time.
From: Jeff Smith, a 35-year veteran of automotive journalism, comes to Power Automedia after serving as the senior technical editor at Car Craft magazine. An Iowa native, Smith served a variety of roles at Car Craft before moving to the senior editor role at Hot Rod and Chevy High Performance, and ultimately returning to Car Craft. An accomplished engine builder and technical expert, he will focus on the tech-heavy content that is the foundation of EngineLabs.
Melting Slicks
Joined: Aug 2004
Posts: 2,149
Likes: 1,349
From: Big D Dallas TEXAS
Even good people make mistakes. Putting cast iron manifolds on would require doing a complete emissions and durability certification that would cost millions. It would add weight, and the weight would be up high, right where you wouldn't want it. Add to this, there is ZERO horsepower gain.
This is a questions I don't know could this new LT2 with a cast iron manifold be used in other vehicles in the GM line up IE like trucks? All about reducing cost and scale which is how GM keeps cost down compared to it's smaller competitors.
Last edited by fasttoys; Aug 9, 2019 at 07:36 AM.
Drifting
Joined: Oct 2006
Posts: 1,372
Likes: 311
From: Bristol, VT
After the article was originally posted, I made a post in ask Tadge requesting clarification, but it hasn't gotten much traction. I suppose we'll find out eventually.
Previously NPP has always been the bimode mufflers, so many assumed that would be the case for C8 as well until the engine labs article suggested otherwise.
It's important to note that it's about the optional exhaust, not Z51. The Z51 just happens to come with the performance exhaust, but the base car can still add it as an option.
Previously NPP has always been the bimode mufflers, so many assumed that would be the case for C8 as well until the engine labs article suggested otherwise.
It's important to note that it's about the optional exhaust, not Z51. The Z51 just happens to come with the performance exhaust, but the base car can still add it as an option.
Race Director
Joined: Aug 2019
Posts: 12,351
Likes: 14,180
From: Central Illinois
Safety Car
Joined: Jul 2019
Posts: 4,079
Likes: 2,413
From: Florida
Mike
Team Owner
Joined: Feb 2013
Posts: 22,598
Likes: 14,555
Every car seen to date has tubular mid-length headers. The production headers clearly have heat shield mount bosses in the same exact places as the heat shields pictured that some people are claiming as proof there are cast manifolds.
1. There are no cast manifolds on production cars.
2. All will have heat shields... why some thing they wouldn't shows extreme ignorance of radiant heat.
1. There are no cast manifolds on production cars.
2. All will have heat shields... why some thing they wouldn't shows extreme ignorance of radiant heat.
