A quick comparison between the LS2 and the LS6 shows much more than 400 HP
03-19-2005, 08:57 PM
#3
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Interesting to reread the speculation, though, and see that 400hp seems to be about right on for the dynos we have seen so far. I was one of the ones who thought it would be underrated, so I get a little reality check...
Todd
Todd
03-20-2005, 01:21 AM
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Originally Posted by WhiteDiamond
Interesting to reread the speculation, though, and see that 400hp seems to be about right on for the dynos we have seen so far. I was one of the ones who thought it would be underrated, so I get a little reality check...
Todd
Todd
Right you are - also - there have been numerous C5 Z06 vs. C6 races both on the track and the street, and it seems that the Z06 has the small edge every time. Given similar gearing etc, you would thing that the greater area under the curve LS2 would win, but it doesn't seem to pan out that way. Very interesting indeed. Given identical rev limiters, and only 5 hp difference, I would think the two would be running even - was it the other way around? Were the LS6 engines the ones that were underrated? What is the average rwhp that the typical LS6 owners see?
03-20-2005, 01:52 AM
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Originally Posted by 415LT5-badZR-1
Right you are - also - there have been numerous C5 Z06 vs. C6 races both on the track and the street, and it seems that the Z06 has the small edge every time. Given similar gearing etc, you would thing that the greater area under the curve LS2 would win, but it doesn't seem to pan out that way. Very interesting indeed. Given identical rev limiters, and only 5 hp difference, I would think the two would be running even - was it the other way around? Were the LS6 engines the ones that were underrated? What is the average rwhp that the typical LS6 owners see?
And the LS2 cam is leaving a lot on the table. I'm anxious to see what just a cam change (and headers) will do for an otherwise stock LS2.
03-20-2005, 02:01 AM
#6
Drifting
Originally Posted by 415LT5-badZR-1
Right you are - also - there have been numerous C5 Z06 vs. C6 races both on the track and the street, and it seems that the Z06 has the small edge every time. Given similar gearing etc, you would thing that the greater area under the curve LS2 would win, but it doesn't seem to pan out that way. Very interesting indeed. Given identical rev limiters, and only 5 hp difference, I would think the two would be running even - was it the other way around? Were the LS6 engines the ones that were underrated? What is the average rwhp that the typical LS6 owners see?
03-20-2005, 02:04 AM
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Originally Posted by THEDVS1
The typical LS6 ('02 and later) will see anywhere from 345 to 365 RWHP. Most people seem confident that the LS6 was UNDERrated by 10-20 hp. No doubt the LS2 is also underrated, but I believe the LS6 still has the edge. And don't forget, the LS6 also has less weight to lug around. Can't forget about that!
365 rwhp is around 425 at the crank - which would explain a lot. Less weight is a big one off the line, but once at speed, aero is more important, and the C6 whops *** on the Z06 there - yet the Z06 still walks away!
03-20-2005, 09:28 AM
#8
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Originally Posted by 415LT5-badZR-1
Were the LS6 engines the ones that were underrated? What is the average rwhp that the typical LS6 owners see?
But I did find this post funny looking back at what was predicted for the LS2. Seems it is rated at 400HP based on the reports of real world owners.
Tom
03-23-2005, 10:21 AM
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Originally Posted by Jim Hall
The C6 is actually 420+ HP.
Why do I suggest that? Three years ago, I posted a thread on the corvetteforum, with a poll asking how many folks would purchase a C5 Coupe with a LS6 option. There were many interested members.
Some quoted Dave Hill as stating that he would never put the Z06 motor in the Coupe or Convertible.
The C6 is just that and more.
400 HP is ridiculous for the amount of internal changes found in the LS2. It is actually a hot rod Z06 motor in sheeps clothing.
A quick comparison: 2004 Z06 has a smaller throttle body-76mm vs. 90 mm for the 2005 C6. The Z06 has a 5.7 liter motor vs. the 6.0 liter LS2. The intake manifold has been redesigned to accomodate the better flow characteristics of the throttle body, and the heads are also improved from a port configuration standpoint. i.e. a ported LS6 head. The compression ratio was automatically increased with the new swept volume from the additional displacement and Z06 combusion chambers to 10.9:1 vs. 10.5:1. Iridium plugs, and hotter coils mean better combustion.
Bigger fuel injectors than the 2004 Z06 with four hole injectors are rated at 4.1 g/s vs the older 3.67 g/s (both at 400 kilopascal or 58 psi rail pressure)
The Z06 heads being utilized flow 15% more air on the intake side, and 21% more on the exhaust port side. 2.00"/1.55" valves are the same steel valves as the LS1. but the springs are Z06.
The exhaust manifolds flow 4% better than the Z06 exhaust manifold (our dyno testing in 2001 suggested that shorty headers vs. the LS6 headers, showed zero improvement in horsepower or torque, so GM has done some homework here) with the straight through mufflers reducing backpressure 10%, and now no pup cats! Finally. No A.I.R. pump! Bay to bay breathing as in the Gen III Z06, has been a part of the LS1 and LS6 for a few years now.
The cam used is the 2001 Z06 cam, with a .525"/.525" lift (2004 Z06 cam is .555"/.551" and similar duration, so here you can subtract 10 RWHP, for the C6 with the same head port design, but with the increase port flow, the actual loss from a lower lift may be insignificant. We have the present Z06 cams, ready to install as soon as our C6 comes in.
They have also gone back to the lower tension rings found in the 2001 Z06, but without the oil consumption problems, which means less frictional losses. Anodized ring lands, may help strengthen the lands, but not from forced induction senarios. I am very disappointed that forged pistons were not used.
GM would have you compare the LS2 to the LS1 to keep the Z06 hot rodders happy, but the truth is out there. The real comparison should be the LS2 vs. the LS6. The LS2 is the new KING of horsepower, no matter how GM spins it.
With all of the above changes to the basic Z06 platform, do they expect anyone to believe that there is only 5 HP LESS than the Z06...???
From a marketing standpoint, it would kill the remaining 2004 Z06 sales, if the new C6 became available with 420 advertised HP.
One more thing. When the Z06 (LS7) motor hits the scene, the 3 valve head design, dry sump, and 427 cid will bump the horsepower to 535. GM will claim much less on paper.
Jim Hall
[Modified by Jim Hall, 7:53 PM 4/29/2004]
Why do I suggest that? Three years ago, I posted a thread on the corvetteforum, with a poll asking how many folks would purchase a C5 Coupe with a LS6 option. There were many interested members.
Some quoted Dave Hill as stating that he would never put the Z06 motor in the Coupe or Convertible.
The C6 is just that and more.
400 HP is ridiculous for the amount of internal changes found in the LS2. It is actually a hot rod Z06 motor in sheeps clothing.
A quick comparison: 2004 Z06 has a smaller throttle body-76mm vs. 90 mm for the 2005 C6. The Z06 has a 5.7 liter motor vs. the 6.0 liter LS2. The intake manifold has been redesigned to accomodate the better flow characteristics of the throttle body, and the heads are also improved from a port configuration standpoint. i.e. a ported LS6 head. The compression ratio was automatically increased with the new swept volume from the additional displacement and Z06 combusion chambers to 10.9:1 vs. 10.5:1. Iridium plugs, and hotter coils mean better combustion.
Bigger fuel injectors than the 2004 Z06 with four hole injectors are rated at 4.1 g/s vs the older 3.67 g/s (both at 400 kilopascal or 58 psi rail pressure)
The Z06 heads being utilized flow 15% more air on the intake side, and 21% more on the exhaust port side. 2.00"/1.55" valves are the same steel valves as the LS1. but the springs are Z06.
The exhaust manifolds flow 4% better than the Z06 exhaust manifold (our dyno testing in 2001 suggested that shorty headers vs. the LS6 headers, showed zero improvement in horsepower or torque, so GM has done some homework here) with the straight through mufflers reducing backpressure 10%, and now no pup cats! Finally. No A.I.R. pump! Bay to bay breathing as in the Gen III Z06, has been a part of the LS1 and LS6 for a few years now.
The cam used is the 2001 Z06 cam, with a .525"/.525" lift (2004 Z06 cam is .555"/.551" and similar duration, so here you can subtract 10 RWHP, for the C6 with the same head port design, but with the increase port flow, the actual loss from a lower lift may be insignificant. We have the present Z06 cams, ready to install as soon as our C6 comes in.
They have also gone back to the lower tension rings found in the 2001 Z06, but without the oil consumption problems, which means less frictional losses. Anodized ring lands, may help strengthen the lands, but not from forced induction senarios. I am very disappointed that forged pistons were not used.
GM would have you compare the LS2 to the LS1 to keep the Z06 hot rodders happy, but the truth is out there. The real comparison should be the LS2 vs. the LS6. The LS2 is the new KING of horsepower, no matter how GM spins it.
With all of the above changes to the basic Z06 platform, do they expect anyone to believe that there is only 5 HP LESS than the Z06...???
From a marketing standpoint, it would kill the remaining 2004 Z06 sales, if the new C6 became available with 420 advertised HP.
One more thing. When the Z06 (LS7) motor hits the scene, the 3 valve head design, dry sump, and 427 cid will bump the horsepower to 535. GM will claim much less on paper.
Jim Hall
[Modified by Jim Hall, 7:53 PM 4/29/2004]
OF COURSE THE GM MARKETING FOLKS UNDERESTIMATE THE HP ON THE C6. THEY WOULD MUCH RATHER MARKET A CAR WITH 400HP THAN 420HP.
03-23-2005, 12:26 PM
#10
Team Owner
Originally Posted by z06monster
OF COURSE THE GM MARKETING FOLKS UNDERESTIMATE THE HP ON THE C6. THEY WOULD MUCH RATHER MARKET A CAR WITH 400HP THAN 420HP.
