LS2 - 395 or 400 hp?
08-26-2007, 07:04 PM
#1
Burning Brakes
Thread Starter
LS2 - 395 or 400 hp?
Ever since the April birthday bash, where a slide was presented showing the LS2 rated at 395 horsepower, there have been numerous threads in which people refer to the LS2 as having 395 SAE Certified horsepower. Since that time I had doubts that the 395 figure was correct, so yesterday at Carlisle I talked to both Tadge Juechter, Corvette Chief Engineer and Harlan Charles, Chevrolet Corvette Product Manager about that slide.
The first question I asked was whether the LS2 had ever been rated under the J2723 certification procedure. Both said the engine never received a certified rating. It is a costly procedure and certainly not worth doing for an engine that would never receive other than a 400 horsepower rating and due for replacement by the LS3.
I then asked about the 395 rating given to LS2 during the slide presentation. Both said the figure was incorrect, the slide was wrong, and that the LS2 really did make 400 horsepower. Both Harlan and Tadge told me the 395 figure came from the Trail Blazer SS and that someone in the chain of operations mistakenly used that figure. This was posted, on this forum, by Harlan Charles back in April.
No engines, that I am aware of, produced by GM, Ford or Chrysler and re-rated under the new methods lost 5 horsepower. I find it highly unlikely that the LS2 would lose 5 hp if it had been re-rated (which it wasn't). In fact, the numbers I saw for US manufacturer engines lost no horsepower and in most cases gained horsepower.
So for all of you who are concerned that the LS2 was less than 400 horsepower, relax, it did make a true 400.
The first question I asked was whether the LS2 had ever been rated under the J2723 certification procedure. Both said the engine never received a certified rating. It is a costly procedure and certainly not worth doing for an engine that would never receive other than a 400 horsepower rating and due for replacement by the LS3.
I then asked about the 395 rating given to LS2 during the slide presentation. Both said the figure was incorrect, the slide was wrong, and that the LS2 really did make 400 horsepower. Both Harlan and Tadge told me the 395 figure came from the Trail Blazer SS and that someone in the chain of operations mistakenly used that figure. This was posted, on this forum, by Harlan Charles back in April.
No engines, that I am aware of, produced by GM, Ford or Chrysler and re-rated under the new methods lost 5 horsepower. I find it highly unlikely that the LS2 would lose 5 hp if it had been re-rated (which it wasn't). In fact, the numbers I saw for US manufacturer engines lost no horsepower and in most cases gained horsepower.
So for all of you who are concerned that the LS2 was less than 400 horsepower, relax, it did make a true 400.
Last edited by Marina Blue; 01-21-2008 at 01:50 PM.
08-26-2007, 08:02 PM
#2
Racer
Member Since: Jun 2007
Location: Woodland Hills Utah
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Ever since the April birthday bash, where a slide was presented showing the LS2 rated at 395 horsepower, there have been numerous threads in which people refer to the LS2 as having 395 SAE Certified horsepower. Since that time I had doubts that the 395 figure was correct, so yesterday at Carlisle I talked to both Tadge Juechter, Corvette Chief Engineer and Harlan Charles, Chevrolet Corvette Product Manager about that slide.
The first question I asked was whether the LS2 had ever been rated under the J2723 certification procedure. Both said the engine never received a certified rating. It is a costly procedure and certainly not worth doing for an engine that would never receive other than a 400 horsepower rating and due for replacement by the LS3.
I then asked about the 395 rating given to LS2 during the slide presentation. Both said the figure was incorrect, the slide was wrong, and that the LS2 really did make 400 horsepower. Both Harlan and Tadge told me the 395 figure came from the Trail Blazer SS and that someone in the chain of operations mistakenly used that figure. This was posted, on this forum, by Harlan Charles back in April.
No engines, that I am aware of, produced by GM, Ford or Chrysler and re-rated under the new methods lost 5 horsepower. I find it highly unlikely that the LS2 would lose 5 hp if it had been re-rated (which it wasn't). The numbers I saw, for US manufacturer engines, lost no more than 1 or 2 horsepower and in most cases gained horsepower.
So for all of you who are concerned that the LS2 was less than 400 horsepower, relax, it did make a true 400.
The first question I asked was whether the LS2 had ever been rated under the J2723 certification procedure. Both said the engine never received a certified rating. It is a costly procedure and certainly not worth doing for an engine that would never receive other than a 400 horsepower rating and due for replacement by the LS3.
I then asked about the 395 rating given to LS2 during the slide presentation. Both said the figure was incorrect, the slide was wrong, and that the LS2 really did make 400 horsepower. Both Harlan and Tadge told me the 395 figure came from the Trail Blazer SS and that someone in the chain of operations mistakenly used that figure. This was posted, on this forum, by Harlan Charles back in April.
No engines, that I am aware of, produced by GM, Ford or Chrysler and re-rated under the new methods lost 5 horsepower. I find it highly unlikely that the LS2 would lose 5 hp if it had been re-rated (which it wasn't). The numbers I saw, for US manufacturer engines, lost no more than 1 or 2 horsepower and in most cases gained horsepower.
So for all of you who are concerned that the LS2 was less than 400 horsepower, relax, it did make a true 400.
08-26-2007, 08:38 PM
#4
Melting Slicks
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The intake for the SS is unbelievable restrictive and just plain stupid.
08-26-2007, 11:18 PM
#5
Ever since the April birthday bash, where a slide was presented showing the LS2 rated at 395 horsepower, there have been numerous threads in which people refer to the LS2 as having 395 SAE Certified horsepower. Since that time I had doubts that the 395 figure was correct, so yesterday at Carlisle I talked to both Tadge Juechter, Corvette Chief Engineer and Harlan Charles, Chevrolet Corvette Product Manager about that slide.
The first question I asked was whether the LS2 had ever been rated under the J2723 certification procedure. Both said the engine never received a certified rating. It is a costly procedure and certainly not worth doing for an engine that would never receive other than a 400 horsepower rating and due for replacement by the LS3.
I then asked about the 395 rating given to LS2 during the slide presentation. Both said the figure was incorrect, the slide was wrong, and that the LS2 really did make 400 horsepower. Both Harlan and Tadge told me the 395 figure came from the Trail Blazer SS and that someone in the chain of operations mistakenly used that figure. This was posted, on this forum, by Harlan Charles back in April.
No engines, that I am aware of, produced by GM, Ford or Chrysler and re-rated under the new methods lost 5 horsepower. I find it highly unlikely that the LS2 would lose 5 hp if it had been re-rated (which it wasn't). The numbers I saw, for US manufacturer engines, lost no more than 1 or 2 horsepower and in most cases gained horsepower.
So for all of you who are concerned that the LS2 was less than 400 horsepower, relax, it did make a true 400.
The first question I asked was whether the LS2 had ever been rated under the J2723 certification procedure. Both said the engine never received a certified rating. It is a costly procedure and certainly not worth doing for an engine that would never receive other than a 400 horsepower rating and due for replacement by the LS3.
I then asked about the 395 rating given to LS2 during the slide presentation. Both said the figure was incorrect, the slide was wrong, and that the LS2 really did make 400 horsepower. Both Harlan and Tadge told me the 395 figure came from the Trail Blazer SS and that someone in the chain of operations mistakenly used that figure. This was posted, on this forum, by Harlan Charles back in April.
No engines, that I am aware of, produced by GM, Ford or Chrysler and re-rated under the new methods lost 5 horsepower. I find it highly unlikely that the LS2 would lose 5 hp if it had been re-rated (which it wasn't). The numbers I saw, for US manufacturer engines, lost no more than 1 or 2 horsepower and in most cases gained horsepower.
So for all of you who are concerned that the LS2 was less than 400 horsepower, relax, it did make a true 400.
1. Did they explain that the testing procedure was costly? How is the testing procedure "costly"? Why would it cost GM any more to test the LS2 according to the new guidelines than it was costing to test the other engines they had tested under the new guidelines?
I ask this question because the LS7 was initially tested under the new guidelines in 2005. The LS2 continued for the '06 and '07 model years, yet was never tested even though multiple other GM engines were being tested under the new guidelines while the LS2 was on the market..
Plenty of time to test it, along with, the Northstar V8 which went into the 2006 Cadillac XLR, and the 3.9L V-6, the 2.4-liter Ecotec, and other engines found in the Pontiac G6.
http://www.cars.com/go/news/Story.js...er=&aff=sacbee
"GM has submitted results from 11 engine lines — covering popular vehicles such as the Chevrolet Malibu and Impala, Pontiac G6 and Cadillac DTS — to SAE for certification. The tests bumped up the horsepower ratings for the Malibu, Impala and G6 by 1 for 2006."
They tested the above engines according to the new SAE guidelines but not the LS2, an engine going into one of their flagship products????.....Because the testing was too costly???
I suspect that the reason why it was not tested, was because they knew that they could never advertise it as 400hp under the new SAE guidelines.
http://www.caranddriver.com/columns/...esolution.html
"....Since minute differences in the dimensions of engine components that naturally occur during series production—the compression ratio could be a smidge higher in one engine versus another—can result in two identical-looking engines making slightly different horsepower, the SAE allows a one-percent tolerance between the number that the witness observes and the horsepower rating that a manufacturer chooses to publish. For example, according to DaimlerChrysler’s senior manager of SRT Powertrain, Pete Gladysz, Dodge rates its Viper V-10 at 510 horsepower, even though a randomly selected V-10 that was plucked from the assembly line and broken in according to DC’s usual cycle developed 512 horsepower on the dyno run for the designated witness. Sometimes a bunch of components are at the outer edge of production tolerances, and the combination hurts the engine’s output. Sometimes they help it. The 0.4-percent difference between the V-10’s observed output and its rating lies well within the SAE’s allowable tolerance band. In fact, Dodge could have rated the engine at 517 horsepower and still met the SAE’s one-percent tolerance. “But we’d rather deliver more than we promise,” said Gladysz."
So testing the LS2 according to the new guidelines for the '06 and '07 model Corvette, could very well have resulted in them having to advertise it at something less than 400hp.
Had this happened, what would it have meant for 2005 owners?? It would have been a disaster.
Had the witness observed anything less than about 396 horsepower, Chevy could not have claimed a Certified 400 horsepower for the LS2. If he had observed 395, then Chevy would have to advertise that as a Certified 398HP. A marketing disaster. Thus IMO, a more likely scenario is not that the test was "too expensive" but that rather Chevy was not willing to take that chance that the LS2 would come in at less than 396hp in the presence of a witness.
The ECM tuning would also have to be the same found in the production vehicle, so no shenanigans could be played there either.
Furthermore, had it come in at say 406 HP in the presence of the same witness, Chevy could have advertised it as a Certified 410hp.
So why would they not jump at that chance???? If they were cocksure about at least 400 then why not have it tested and gain a few more horses for essentially free?? As mentioned before, had it put down 406 in front of that witness, Chevy could have called it 410. Why wouldn't they want to do this??? Why pass up such a golden opportunity????
I think they passed on that fight because they knew it was one where they had nothing to gain, and could perhaps lose quite a bit if the numbers had gone against them and they had to call the Corvette something less than 400hp.
I believe that they hid it from that test because they knew it wouldn't make it, or they were not 100% confident that it would make it. Its like a prizefighter ducking an extremely lucrative fight. He and his management have to have a reason for ducking it.
Last edited by '06 Quicksilver Z06; 08-26-2007 at 11:46 PM.
08-27-2007, 12:58 AM
#7
Burning Brakes
Thread Starter
I have a couple of questions and I hope that you can answer them for me.
1. Did they explain that the testing procedure was costly? How is the testing procedure "costly"? Why would it cost GM any more to test the LS2 according to the new guidelines than it was costing to test the other engines they had tested under the new guidelines?
I ask this question because the LS7 was initially tested under the new guidelines in 2005. The LS2 continued for the '06 and '07 model years, yet was never tested even though multiple other GM engines were being tested under the new guidelines while the LS2 was on the market..
Plenty of time to test it, along with, the Northstar V8 which went into the 2006 Cadillac XLR, and the 3.9L V-6, the 2.4-liter Ecotec, and other engines found in the Pontiac G6.
http://www.cars.com/go/news/Story.js...er=&aff=sacbee
"GM has submitted results from 11 engine lines — covering popular vehicles such as the Chevrolet Malibu and Impala, Pontiac G6 and Cadillac DTS — to SAE for certification. The tests bumped up the horsepower ratings for the Malibu, Impala and G6 by 1 for 2006."
They tested the above engines according to the new SAE guidelines but not the LS2, an engine going into one of their flagship products????.....Because the testing was too costly???
I suspect that the reason why it was not tested, was because they knew that they could never advertise it as 400hp under the new SAE guidelines.
http://www.caranddriver.com/columns/...esolution.html
"....Since minute differences in the dimensions of engine components that naturally occur during series production—the compression ratio could be a smidge higher in one engine versus another—can result in two identical-looking engines making slightly different horsepower, the SAE allows a one-percent tolerance between the number that the witness observes and the horsepower rating that a manufacturer chooses to publish. For example, according to DaimlerChrysler’s senior manager of SRT Powertrain, Pete Gladysz, Dodge rates its Viper V-10 at 510 horsepower, even though a randomly selected V-10 that was plucked from the assembly line and broken in according to DC’s usual cycle developed 512 horsepower on the dyno run for the designated witness. Sometimes a bunch of components are at the outer edge of production tolerances, and the combination hurts the engine’s output. Sometimes they help it. The 0.4-percent difference between the V-10’s observed output and its rating lies well within the SAE’s allowable tolerance band. In fact, Dodge could have rated the engine at 517 horsepower and still met the SAE’s one-percent tolerance. “But we’d rather deliver more than we promise,” said Gladysz."
So testing the LS2 according to the new guidelines for the '06 and '07 model Corvette, could very well have resulted in them having to advertise it at something less than 400hp.
Had this happened, what would it have meant for 2005 owners?? It would have been a disaster.
Had the witness observed anything less than about 396 horsepower, Chevy could not have claimed a Certified 400 horsepower for the LS2. If he had observed 395, then Chevy would have to advertise that as a Certified 398HP. A marketing disaster. Thus IMO, a more likely scenario is not that the test was "too expensive" but that rather Chevy was not willing to take that chance that the LS2 would come in at less than 396hp in the presence of a witness.
The ECM tuning would also have to be the same found in the production vehicle, so no shenanigans could be played there either.
Furthermore, had it come in at say 406 HP in the presence of the same witness, Chevy could have advertised it as a Certified 410hp.
So why would they not jump at that chance???? If they were cocksure about at least 400 then why not have it tested and gain a few more horses for essentially free?? As mentioned before, had it put down 406 in front of that witness, Chevy could have called it 410. Why wouldn't they want to do this??? Why pass up such a golden opportunity????
I think they passed on that fight because they knew it was one where they had nothing to gain, and could perhaps lose quite a bit if the numbers had gone against them and they had to call the Corvette something less than 400hp.
I believe that they hid it from that test because they knew it wouldn't make it, or they were not 100% confident that it would make it. Its like a prizefighter ducking an extremely lucrative fight. He and his management have to have a reason for ducking it.
1. Did they explain that the testing procedure was costly? How is the testing procedure "costly"? Why would it cost GM any more to test the LS2 according to the new guidelines than it was costing to test the other engines they had tested under the new guidelines?
I ask this question because the LS7 was initially tested under the new guidelines in 2005. The LS2 continued for the '06 and '07 model years, yet was never tested even though multiple other GM engines were being tested under the new guidelines while the LS2 was on the market..
Plenty of time to test it, along with, the Northstar V8 which went into the 2006 Cadillac XLR, and the 3.9L V-6, the 2.4-liter Ecotec, and other engines found in the Pontiac G6.
http://www.cars.com/go/news/Story.js...er=&aff=sacbee
"GM has submitted results from 11 engine lines — covering popular vehicles such as the Chevrolet Malibu and Impala, Pontiac G6 and Cadillac DTS — to SAE for certification. The tests bumped up the horsepower ratings for the Malibu, Impala and G6 by 1 for 2006."
They tested the above engines according to the new SAE guidelines but not the LS2, an engine going into one of their flagship products????.....Because the testing was too costly???
I suspect that the reason why it was not tested, was because they knew that they could never advertise it as 400hp under the new SAE guidelines.
http://www.caranddriver.com/columns/...esolution.html
"....Since minute differences in the dimensions of engine components that naturally occur during series production—the compression ratio could be a smidge higher in one engine versus another—can result in two identical-looking engines making slightly different horsepower, the SAE allows a one-percent tolerance between the number that the witness observes and the horsepower rating that a manufacturer chooses to publish. For example, according to DaimlerChrysler’s senior manager of SRT Powertrain, Pete Gladysz, Dodge rates its Viper V-10 at 510 horsepower, even though a randomly selected V-10 that was plucked from the assembly line and broken in according to DC’s usual cycle developed 512 horsepower on the dyno run for the designated witness. Sometimes a bunch of components are at the outer edge of production tolerances, and the combination hurts the engine’s output. Sometimes they help it. The 0.4-percent difference between the V-10’s observed output and its rating lies well within the SAE’s allowable tolerance band. In fact, Dodge could have rated the engine at 517 horsepower and still met the SAE’s one-percent tolerance. “But we’d rather deliver more than we promise,” said Gladysz."
So testing the LS2 according to the new guidelines for the '06 and '07 model Corvette, could very well have resulted in them having to advertise it at something less than 400hp.
Had this happened, what would it have meant for 2005 owners?? It would have been a disaster.
Had the witness observed anything less than about 396 horsepower, Chevy could not have claimed a Certified 400 horsepower for the LS2. If he had observed 395, then Chevy would have to advertise that as a Certified 398HP. A marketing disaster. Thus IMO, a more likely scenario is not that the test was "too expensive" but that rather Chevy was not willing to take that chance that the LS2 would come in at less than 396hp in the presence of a witness.
The ECM tuning would also have to be the same found in the production vehicle, so no shenanigans could be played there either.
Furthermore, had it come in at say 406 HP in the presence of the same witness, Chevy could have advertised it as a Certified 410hp.
So why would they not jump at that chance???? If they were cocksure about at least 400 then why not have it tested and gain a few more horses for essentially free?? As mentioned before, had it put down 406 in front of that witness, Chevy could have called it 410. Why wouldn't they want to do this??? Why pass up such a golden opportunity????
I think they passed on that fight because they knew it was one where they had nothing to gain, and could perhaps lose quite a bit if the numbers had gone against them and they had to call the Corvette something less than 400hp.
I believe that they hid it from that test because they knew it wouldn't make it, or they were not 100% confident that it would make it. Its like a prizefighter ducking an extremely lucrative fight. He and his management have to have a reason for ducking it.
I returned to the tent yet another time because of my shortened talk with Tadge Juechter. He was not there, but Harlan Charles was. Harlan not only answered the questions I previously mentioned, but a third question concerning the source of that 407 figure that both you and I plus a few others here discussed in the past. He had no knowledge of it but did mention the normal production variances in manufacturing. As we both know, the 407 figure turned out to be BS.
So, that is what I went through to get a reliable answer concerning that 395 figure on the birthday bash slide. The depth of the conversation went no further than what I mentioned so I have no answer for your remaining thoughts. However, I often had some of the same thoughts as you, thinking there was free advertised horsepower to be had if they went to a certified rating. At this point it is evident why that was never done. It wasn’t possible because the LS2 only rated 400. Remember that Hot Rod article where Katech dyon’d a stock LS2 crate engine that rated exactly 400 on their water-brake dyno.
I know this response is not enough to answer all of your concerns, but this is where and how I got the information that I presented and I can’t say much more than I already have.
08-27-2007, 01:27 AM
#8
Burning Brakes
Thread Starter
I'm sure they had nothing to gain, which is good reason to not bother with certification and re-rating at 400 again. I know your assertion is that it rated less than 400. If it would have, it wouldn't have been by much and from what I am seeing would not have lost 5 hp. And that last statement is where all h--l seems to break loose on this forum. I hate to fall back on this, but don't forget that Katech dyno result: http://www.hotrod.com/techarticles/1...l_block_build/
08-27-2007, 01:48 AM
#9
tough time to hold your head up if the C6 was 395 not 400....
This thread is almost as ridiculous as ones that maintained that the extra 5 hp of the C5 Z06 made it considerably more powerful than the then new C6 which had 'only' 400. Personally, I think it would have been neat if GM had labeled the LS2 as 396hp!
There have been posts that have claimed the 430 or 436 hp of the LS3 would be no big thing over the LS2 and probably not noticeable.....and you guys are having male menopausal hot flashes over the horrible possibility that your car makes a few less than 400 hp? Oh, the humanity!
Here's a news flash: The 08 LS3 C6 NPP has about 70hp less than the Z06. Not 100 or 105, 70 and weighs only about 50 lbs more. It's closer to Z06 performance by a third than the LS2 cars. So does this mean that Z06 owners will now start to claim even louder than their cars make more than 505 hp? What if they made 498? Would they even want to keep their cars?
All this splitting hairs over a few hp seems pointless to me....except that I understand the male dominance angle-the mine is bigger than yours thang....
There have been posts that have claimed the 430 or 436 hp of the LS3 would be no big thing over the LS2 and probably not noticeable.....and you guys are having male menopausal hot flashes over the horrible possibility that your car makes a few less than 400 hp? Oh, the humanity!
Here's a news flash: The 08 LS3 C6 NPP has about 70hp less than the Z06. Not 100 or 105, 70 and weighs only about 50 lbs more. It's closer to Z06 performance by a third than the LS2 cars. So does this mean that Z06 owners will now start to claim even louder than their cars make more than 505 hp? What if they made 498? Would they even want to keep their cars?
All this splitting hairs over a few hp seems pointless to me....except that I understand the male dominance angle-the mine is bigger than yours thang....
08-27-2007, 02:52 AM
#10
I'm sure they had nothing to gain, which is good reason to not bother with certification and re-rating at 400 again. I know your assertion is that it rated less than 400. If it would have, it wouldn't have been by much and from what I am seeing would not have lost 5 hp. And that last statement is where all h--l seems to break loose on this forum. I hate to fall back on this, but don't forget that Katech dyno result: http://www.hotrod.com/techarticles/1...l_block_build/
but if memory serves me, the testing done by Katech used a PCM from a C5 Z06.
Part of the reqirements for the new testing methods stipulate that the ECM parameters, ie the tuning, must be consistent with what the consumer will get in the car he purchases.
Now whether that ECM used in the Katech testing made a difference or not, I do not know. But if my assumption is right and my memory accurate, then the LS2 testing by Katech, which yielded 400hp, was not done using an ECM which would be found in a consumer's C6. And the injectors were changed.
"Katech also swapped the LS2's stock 33-lb/hr injectors for a set of GMPP ASA-series crate-engine 36-lb/hr injectors primarily because the older-style injectors use standard LS1-type injector plugs (the ASA injectors are actually the same as those used on L67 supercharged 3.8L V-6 engines). And since GMPP does not offer the LS2 with a standalone computer controller, an '04 LS6 Corvette ECM calibrated to run the same size injectors took its place."
These alone would not have been suitable for meeting the testing requirements for the new SAE ratings since the consumer version of the engine is not configured in this manner. Different injectors, different computer.
The article on the Viper indicates that testing occurs on a randomly selected production engine intended for installation into one of the production and for sale to the public vehicles.
"...For example, according to DaimlerChrysler’s senior manager of SRT Powertrain, Pete Gladysz, Dodge rates its Viper V-10 at 510 horsepower, even though a randomly selected V-10 that was plucked from the assembly line and broken in according to DC’s usual cycle developed 512 horsepower on the dyno run for the designated witness...."
http://www.caranddriver.com/columns/...esolution.html
The engine tested by Katech would not meet that requirement.
Finally, it is difficult for "some" to imagine that if one paid for 400hp then thats what they want, 400hp. Not 396.
This is why GM stuck with the old ratings system for the LS2. Under that ratings method they could "accurately" claim it at 400 hp. So yes, an LS2 based C6 makes 400hp under the old ratings system used to rate them when they were sold. We won't go into the leeway and loopholes available in that ratings method, which are non existent now.
However had GM switched to the new SAE method or rating horsepower, and used this method for the remaining or upcoming '06 and '07 LS2 Corvettes, there is a chance, .....and I believe a good chance, that they would not have been able to advertise it at 400hp.
I say a "good chance" because the LS3 chassis dyno numbers are so far ahead of the LS2 numbers. That tells me that something is up. Also I go back to the fact that GM was reluctant to "expose" the LS2 used in the C6 to the new SAE testing guidelines.
I believe that they knew this. Why else hide it from the testing? Why duck the test unless they were afraid of, or unsure of, the outcome? A "favorable" result and they get a free horsepower bump. But a "less than favorable result"......or a result that they knew was likely
and there would be a tough row to hoe.
Last edited by '06 Quicksilver Z06; 08-27-2007 at 03:16 AM.
08-27-2007, 03:18 AM
#12
It also means that the SAE Certified ratings, used for the LS3 and LS7, are much more reliable for comparison purposes than attempting to compare an engine's power using one ratings method vs stated power of a second engine using another ratings method.
Simply put, all indication thus far is that the LS3 is at least 30-36 horsepower stronger than the LS2 it replaced and there is strong indication that it is even stronger than 30-36. Possibly or even probably more like 35-41 horsepower stronger.
We aren't talking 436-400. We are talking 436-X. Where X may or may not be 400 and is quite possibly less than 400. So its not necessarily accurate to say that "the C6 got a 30-36hp bump". It may have gotten more than that and indications are that it did.
However in the case of the LS7 and the LS3, we are talking 505-430 or 505-436. All figures being SAE certified horsepower ratings
Last edited by '06 Quicksilver Z06; 08-27-2007 at 03:29 AM.
08-27-2007, 03:28 AM
#13
Burning Brakes
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Holy crap you are suspicious, dude.
Think of it this way, testing is not free. Yes, they could have gained power, or they could have lost rated power. Neither would have changed the actual performance, and they already knew there was a new engine coming in for 08. There was no reason to retest. Period. End of story.
If you want to complain about something, go bitch at the imports that lost 10-15 rated HP and still cant get out of their own way.
Think of it this way, testing is not free. Yes, they could have gained power, or they could have lost rated power. Neither would have changed the actual performance, and they already knew there was a new engine coming in for 08. There was no reason to retest. Period. End of story.
If you want to complain about something, go bitch at the imports that lost 10-15 rated HP and still cant get out of their own way.
08-27-2007, 07:08 AM
#15
Burning Brakes
Thread Starter
I have a couple of questions and I hope that you can answer them for me.
I ask this question because the LS7 was initially tested under the new guidelines in 2005. The LS2 continued for the '06 and '07 model years, yet was never tested even though multiple other GM engines were being tested under the new guidelines while the LS2 was on the market..
Plenty of time to test it, along with, the Northstar V8 which went into the 2006 Cadillac XLR, and the 3.9L V-6, the 2.4-liter Ecotec, and other engines found in the Pontiac G6.
http://www.cars.com/go/news/Story.js...er=&aff=sacbee
"GM has submitted results from 11 engine lines — covering popular vehicles such as the Chevrolet Malibu and Impala, Pontiac G6 and Cadillac DTS — to SAE for certification. The tests bumped up the horsepower ratings for the Malibu, Impala and G6 by 1 for 2006."
They tested the above engines according to the new SAE guidelines but not the LS2, an engine going into one of their flagship products????.....Because the testing was too costly???
I suspect that the reason why it was not tested, was because they knew that they could never advertise it as 400hp under the new SAE guidelines.
I ask this question because the LS7 was initially tested under the new guidelines in 2005. The LS2 continued for the '06 and '07 model years, yet was never tested even though multiple other GM engines were being tested under the new guidelines while the LS2 was on the market..
Plenty of time to test it, along with, the Northstar V8 which went into the 2006 Cadillac XLR, and the 3.9L V-6, the 2.4-liter Ecotec, and other engines found in the Pontiac G6.
http://www.cars.com/go/news/Story.js...er=&aff=sacbee
"GM has submitted results from 11 engine lines — covering popular vehicles such as the Chevrolet Malibu and Impala, Pontiac G6 and Cadillac DTS — to SAE for certification. The tests bumped up the horsepower ratings for the Malibu, Impala and G6 by 1 for 2006."
They tested the above engines according to the new SAE guidelines but not the LS2, an engine going into one of their flagship products????.....Because the testing was too costly???
I suspect that the reason why it was not tested, was because they knew that they could never advertise it as 400hp under the new SAE guidelines.
Go back to 2004. I remember the 6.2 liter engine was being considered as a possibility for the upcoming C6 Z06. At the time we had no idea what engine was going in the Z06, but you can be sure GM did. Their product planning is years ahead of what we know about. We didn't even know about the switch to the 6.2 in the base Vette until a few months ago. Why would they bother going through a certification of an engine like LS2 when they knew it was going to be cancelled?
Last edited by Marina Blue; 08-27-2007 at 07:10 AM.
08-27-2007, 07:17 AM
#16
Burning Brakes
Thread Starter
Ah yes my friend.
but if memory serves me, the testing done by Katech used a PCM from a C5 Z06.
Part of the reqirements for the new testing methods stipulate that the ECM parameters, ie the tuning, must be consistent with what the consumer will get in the car he purchases.
Now whether that ECM used in the Katech testing made a difference or not, I do not know. But if my assumption is right and my memory accurate, then the LS2 testing by Katech, which yielded 400hp, was not done using an ECM which would be found in a consumer's C6. And the injectors were changed.
"Katech also swapped the LS2's stock 33-lb/hr injectors for a set of GMPP ASA-series crate-engine 36-lb/hr injectors primarily because the older-style injectors use standard LS1-type injector plugs (the ASA injectors are actually the same as those used on L67 supercharged 3.8L V-6 engines). And since GMPP does not offer the LS2 with a standalone computer controller, an '04 LS6 Corvette ECM calibrated to run the same size injectors took its place."
These alone would not have been suitable for meeting the testing requirements for the new SAE ratings since the consumer version of the engine is not configured in this manner. Different injectors, different computer.
The article on the Viper indicates that testing occurs on a randomly selected production engine intended for installation into one of the production and for sale to the public vehicles.
"...For example, according to DaimlerChrysler’s senior manager of SRT Powertrain, Pete Gladysz, Dodge rates its Viper V-10 at 510 horsepower, even though a randomly selected V-10 that was plucked from the assembly line and broken in according to DC’s usual cycle developed 512 horsepower on the dyno run for the designated witness...."
http://www.caranddriver.com/columns/...esolution.html
The engine tested by Katech would not meet that requirement.
but if memory serves me, the testing done by Katech used a PCM from a C5 Z06.
Part of the reqirements for the new testing methods stipulate that the ECM parameters, ie the tuning, must be consistent with what the consumer will get in the car he purchases.
Now whether that ECM used in the Katech testing made a difference or not, I do not know. But if my assumption is right and my memory accurate, then the LS2 testing by Katech, which yielded 400hp, was not done using an ECM which would be found in a consumer's C6. And the injectors were changed.
"Katech also swapped the LS2's stock 33-lb/hr injectors for a set of GMPP ASA-series crate-engine 36-lb/hr injectors primarily because the older-style injectors use standard LS1-type injector plugs (the ASA injectors are actually the same as those used on L67 supercharged 3.8L V-6 engines). And since GMPP does not offer the LS2 with a standalone computer controller, an '04 LS6 Corvette ECM calibrated to run the same size injectors took its place."
These alone would not have been suitable for meeting the testing requirements for the new SAE ratings since the consumer version of the engine is not configured in this manner. Different injectors, different computer.
The article on the Viper indicates that testing occurs on a randomly selected production engine intended for installation into one of the production and for sale to the public vehicles.
"...For example, according to DaimlerChrysler’s senior manager of SRT Powertrain, Pete Gladysz, Dodge rates its Viper V-10 at 510 horsepower, even though a randomly selected V-10 that was plucked from the assembly line and broken in according to DC’s usual cycle developed 512 horsepower on the dyno run for the designated witness...."
http://www.caranddriver.com/columns/...esolution.html
The engine tested by Katech would not meet that requirement.
Since we were in Carlisle at the same time we should have gone to the GM tent together. We could have used the tag team approach of questioning to extract more information. On second thought, maybe not--as we probably would have been banished as trouble makers and restricted to the dyno area.
Last edited by Marina Blue; 08-27-2007 at 07:34 AM.
08-27-2007, 08:40 AM
#17
I suspect the LS2 was never tested under the new procedure because GM knew it was destined for cancellation. The other engines you mention here were not.
Go back to 2004. I remember the 6.2 liter engine was being considered as a possibility for the upcoming C6 Z06. At the time we had no idea what engine was going in the Z06, but you can be sure GM did. Their product planning is years ahead of what we know about. We didn't even know about the switch to the 6.2 in the base Vette until a few months ago. Why would they bother going through a certification of an engine like LS2 when they knew it was going to be cancelled?
Go back to 2004. I remember the 6.2 liter engine was being considered as a possibility for the upcoming C6 Z06. At the time we had no idea what engine was going in the Z06, but you can be sure GM did. Their product planning is years ahead of what we know about. We didn't even know about the switch to the 6.2 in the base Vette until a few months ago. Why would they bother going through a certification of an engine like LS2 when they knew it was going to be cancelled?
Holy crap you are suspicious, dude.
Think of it this way, testing is not free. Yes, they could have gained power, or they could have lost rated power. Neither would have changed the actual performance, and they already knew there was a new engine coming in for 08. There was no reason to retest. Period. End of story.
.......
Think of it this way, testing is not free. Yes, they could have gained power, or they could have lost rated power. Neither would have changed the actual performance, and they already knew there was a new engine coming in for 08. There was no reason to retest. Period. End of story.
.......
Very good and touche! I seem to remember those as points I expressed to you when we still thought LS2 was 407.
Since we were in Carlisle at the same time we should have gone to the GM tent together. We could have used the tag team approach of questioning to extract more information. On second thought, maybe not--as we probably would have been banished as trouble makers and restricted to the dyno area.
Since we were in Carlisle at the same time we should have gone to the GM tent together. We could have used the tag team approach of questioning to extract more information. On second thought, maybe not--as we probably would have been banished as trouble makers and restricted to the dyno area.
They would have booted me out anyway, because I would have called 
: to their faces.To both you guys, I enjoy a good debate among respected members of the forum as you two are.
That said, I think your theory has a big hole in it.
http://media.gm.com/us/chevrolet/en/...k%20oview.html
How do you put up a graph comparing LS2 to LS3 at a Corvette gathering, at the museum no less and the engine you have on the graph is not even from out of a Corvette but from out of a truck????
I can't see them making a mistake like that .......but then again, they did have a guy at the plant put out that bogus 407 figure.
Thats why I asked at the beginning about the "expense" of the testing.
I don't see how it costs GM large or significant sums of money to submit an engine, off the shelf which is about to go into a car which they will be selling, for testing.
The only down side I see for them submitting an engine for the new testing was the potential for a lower number.
Of course we are all three speculating as to why GM supposedly ducked the test for the LS2. And we also know that there are no published results for how this engine did under the new SAE guidelines.
Do you think that based upon the amount of improvement they saw when the rerated the Northstar and other engines under the new SAE guidelines, that they had an idea as to where the LS2 engine was going to end up??
Also, I am in a hurry now, and cannot look it up....... but wasn't the LS2 in the Blazer.........rated using the new SAE guidelines???? If so, and the LS2 was a lame duck, why rate it according to the new guidelines in the Blazer, but not in the Vette????
Actually I did look it up http://media.gm.com/us/chevrolet/en/...k%20oview.html
Why rate this outgoing engine under the new system for the trailblazer and not the Vette???
But here is what we have seen so far.
1. Absence of LS2 HP rating under the new SAE guidelines
2. Chassis dyno numbers for the LS3 which are significantly higher than those seen by LS2s and on the same dyno albeit not the same day. The numbers have come from not just LGs dyno but from MTI I believe as well.
3. An '08 example run 12.4 in the 1/4 mile @114.92 during the middle of August, one of the hottest, if not the hottest months of the year, and in the Texas heat.
2 & 3 indicate to me at least a 30-36hp advantage and probably more. The lack/absence of an SAE Certified rating for the LS2, the most reliable form of HP rating available today, makes me wonder even more.
Last edited by '06 Quicksilver Z06; 08-27-2007 at 08:59 AM.
08-27-2007, 09:57 AM
#18
Burning Brakes
Thread Starter
How do you put up a graph comparing LS2 to LS3 at a Corvette gathering, at the museum no less and the engine you have on the graph is not even from out of a Corvette but from out of a truck????
I can't see them making a mistake like that .......but then again, they did have a guy at the plant put out that bogus 407 figure.
I can't see them making a mistake like that .......but then again, they did have a guy at the plant put out that bogus 407 figure.
Mistakes happen and in this case there were at least two. I'm sure there were many people involved in the background work for the birthday bash presentation. I can understand how a person or persons responsible for the slide information made a mistake. Not all people involved in the process are Corvette aficionados like us and therefore not aware of details like we are.
Also, I am in a hurry now, and cannot look it up....... but wasn't the LS2 in the Blazer.........rated using the new SAE guidelines???? If so, and the LS2 was a lame duck, why rate it according to the new guidelines in the Blazer, but not in the Vette????
Actually I did look it up http://media.gm.com/us/chevrolet/en/...k%20oview.html
Why rate this outgoing engine under the new system for the trailblazer and not the Vette???
Actually I did look it up http://media.gm.com/us/chevrolet/en/...k%20oview.html
Why rate this outgoing engine under the new system for the trailblazer and not the Vette???
TrailBlazer – For ’07, the Trailblazer SS becomes a distinct model and is available in two equipment packages: 1SS and 3SS. TrailBlazer SS has unique exterior styling and specific interior appointments, including 20-inch flangeless wheels. Power comes from a Corvette-derived LS2 6.0L V-8, which produces 395 horsepower (295 kW) and 400 lb.-ft. of torque (542 Nm) – enabling the powerful SUV to reach 60 mph in 5.7 seconds. A performance suspension with lowered ride height also is part of the package. The TrailBlazer SS is available in two-wheel drive and all-wheel drive configurations.
Also for 2007, the Uplander is upgraded with the GM 3.9L V-6 with variable valve timing (VVT) as standard on all models. This powerful and refined V-6 delivers 240 horsepower (179 kW) and 240 lb.-ft. (325 Nm) of torque* – a FlexFuel version capable of running on E85 ethanol will be available later in the model year for fleet models.
* Horsepower and torque SAE certified. A new voluntary power and torque certification procedure developed by the SAE Engine Test Code committee was approved March 31, 2005 . This procedure (J2723) ensures fair, accurate ratings for horsepower and torque by allowing manufacturers to certify their engines through third-party witness testing. GM was the first auto manufacturer to begin using the procedure and expects to use it for all newly rated engines in the future.
The above is proof that both Tadge Juechter and Harlan Charles gave me correct information in stating the LS2 was never certified.
But here is what we have seen so far.
2. Chassis dyno numbers for the LS3 which are significantly higher than those seen by LS2s and on the same dyno albeit not the same day. The numbers have come from not just LGs dyno but from MTI I believe as well.
2 & 3 indicate to me at least a 30-36hp advantage and probably more.
2. Chassis dyno numbers for the LS3 which are significantly higher than those seen by LS2s and on the same dyno albeit not the same day. The numbers have come from not just LGs dyno but from MTI I believe as well.
2 & 3 indicate to me at least a 30-36hp advantage and probably more.
375 - 340 = 35
400 - 363 = 37
MTI overlayed figures for both a stock LS3 and LS2. LS3 was 390.5 and LS2 was 353.7. The difference is 36.8.
Those figures seem to fall right in line with engines that make 436 and 400 fwhp. Using those numbers, I see no reason to downgrade LS2 to a 395 horsepower engine under any standard.
All of this is legitimate debate and you make good points, but I feel my arguments are solid enough to back up my original post. I see no reason to use an admitted wrong number on a slide presentation as the basis for assuming LS2 should be rated at less than 400 horsepower.
Last edited by Marina Blue; 08-31-2007 at 08:50 PM.
08-27-2007, 10:15 AM
#20
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I don't think this is a hole in any theory, but a mistake as both Tadge Juechter and Harlan Charles stated. You may not remember this, but there was another mistake in the birthday bash slide presentation. The '04 C5 Z06 did the 7:56 Nurburgring time, not the '08 C6 as represented in the presentation.
The MZ6, NPP equipped LS3 now has chassis dyno numbers that vary from 375 to lets call it an even 400. The manual trans LS2 has numbers that vary from 340 to 363 and I believe I also saw a 365 posted somewhere on this forum.
375 - 340 = 35
400 - 363 = 37
MTI overlayed figures for both a stock LS3 and LS2. LS3 was 390.5 and LS2 was 353.7. The difference is 36.8.
Those figures seem to fall right in line with engines that make 436 and 400 fwhp. Using those numbers, I see no reason to downgrade LS2 to a 395 horsepower engine under any standard.
I cannot answer as to why the Trailblazer LS2 was advertised with a certified rating. All I know is that two key people, including the Chief Engineer, told me LS2 was never tested under the J2723 certification procedure.
All of this is legitimate debate and you make good points but I feel my points are just as valid.
I see no reason to use an admitted wrong number on a slide presentation as the basis for downgrading LS2 to 395.
The MZ6, NPP equipped LS3 now has chassis dyno numbers that vary from 375 to lets call it an even 400. The manual trans LS2 has numbers that vary from 340 to 363 and I believe I also saw a 365 posted somewhere on this forum.
375 - 340 = 35
400 - 363 = 37
MTI overlayed figures for both a stock LS3 and LS2. LS3 was 390.5 and LS2 was 353.7. The difference is 36.8.
Those figures seem to fall right in line with engines that make 436 and 400 fwhp. Using those numbers, I see no reason to downgrade LS2 to a 395 horsepower engine under any standard.
I cannot answer as to why the Trailblazer LS2 was advertised with a certified rating. All I know is that two key people, including the Chief Engineer, told me LS2 was never tested under the J2723 certification procedure.
All of this is legitimate debate and you make good points but I feel my points are just as valid.
I see no reason to use an admitted wrong number on a slide presentation as the basis for downgrading LS2 to 395.
Gees...Please no one dare tell this guy they also made a 390 HP version of the LS2 in the SSR/auto...It may result in a total new thread
Dude 395 or 400 makes no real difference. Just drive the car and love the performance!!!!
