400-plus-hp, 6.0-liter V-8 or a 300-plus-hp,3.6-liter V-6
03-17-2008, 09:58 AM
#16
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That may be true.
but when a manual tranny car dynoes 400 at the wheels, that car is making 470 at the crank.
The LS1 and LS2 vette were rated correctly at 350(290RW) and 400hp(340RW). The LS3 vette is underrated by about 40 hp.
And we all know the LS1 Fbods were dynoing about 290 at the wheels, just like the vette, yet were rated at 305.
03-17-2008, 10:10 AM
#17
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Peper also announced that in a matter of weeks Chevy will begin offering its midsize Malibu sedan with a 169-hp, 2.4 liter four-cylinder engine teamed with a six-speed automatic transmission. The sedan will be rated at 22/32 mpg city/highway, which is very close to the Malibu Hybrid’s 24/32 mpg.
The four-cylinder/six-speed Malibu will start at $26,245, which is about $4,000 more than the hybrid, because it willl be offered on the top-of-the-line LTZ trim level, which has the most standard equipment, while the hybrid is offered on the lower LT1 trim level.
The four-cylinder/six-speed Malibu will start at $26,245, which is about $4,000 more than the hybrid, because it willl be offered on the top-of-the-line LTZ trim level, which has the most standard equipment, while the hybrid is offered on the lower LT1 trim level.
I may be trading the Z28 in for a Malibu LTZ.
03-17-2008, 12:38 PM
#18
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That may be true.
but when a manual tranny car dynoes 400 at the wheels, that car is making 470 at the crank.
The LS1 and LS2 vette were rated correctly at 350(290RW) and 400hp(340RW). The LS3 vette is underrated by about 40 hp.
And we all know the LS1 Fbods were dynoing about 290 at the wheels, just like the vette, yet were rated at 305.
but when a manual tranny car dynoes 400 at the wheels, that car is making 470 at the crank.
The LS1 and LS2 vette were rated correctly at 350(290RW) and 400hp(340RW). The LS3 vette is underrated by about 40 hp.
And we all know the LS1 Fbods were dynoing about 290 at the wheels, just like the vette, yet were rated at 305.
And where did you get 400rwhp from? Last I saw it was 370rwhp for an A6 and 385-390 for the M6. That gives them close to the same loss as a Z06, Viper, GT500 or even a GTO.
I've never heard of a good running LS1 putting 290 to the wheels either. My 01 M6 car put down 310 when it was new.
03-17-2008, 01:12 PM
#19
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03-17-2008, 04:06 PM
#20
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The LS3 is underrated by nothing. It was SAE certified at 430 and 436hp depending on exhaust. That means every Corvette LS3 coming off the line is within 1% of that at the crank, regardless of transmission. If it was really making 470 that's what it would've been certified at. The SAE cerification process has put an end to underrating.
And where did you get 400rwhp from? Last I saw it was 370rwhp for an A6 and 385-390 for the M6. That gives them close to the same loss as a Z06, Viper, GT500 or even a GTO.
I've never heard of a good running LS1 putting 290 to the wheels either. My 01 M6 car put down 310 when it was new.
And where did you get 400rwhp from? Last I saw it was 370rwhp for an A6 and 385-390 for the M6. That gives them close to the same loss as a Z06, Viper, GT500 or even a GTO.
I've never heard of a good running LS1 putting 290 to the wheels either. My 01 M6 car put down 310 when it was new.
Man you are freakin dense. You claim YOUR OWN car put down 310 at the wheels stock and then keep arguing the SAE rating of 305hp AT THE CRANK for a '01 LS1 is correct?
I have seen at least 3 posted dynos of bone stock M6 '08s putting down 395-400 at the wheels.
Here's another one.
http://forums.corvetteforum.com/show...ght=stock+dyno
An engine that was making 436(Z06 exhaust option) it would dyno 370 at the wheels. There are no '08 M6s dynoing that low unless they're F'd up. The LS3 is a 460-470hp engine.
And before you claim that the dynos are reading high, the M6 LS2 vettes were all dynoing around 340 at the wheels which matches up with the SAE rating of 400hp.
Why would Chevy underrate the LS3? Because Chevy has to move the Z06. It's pretty hard to sell Chevy's halo car for $80K sitting next to a $50K Vette making only 35hp less.
03-17-2008, 04:50 PM
#21
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Location: Mill Creek, WA
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Man you are freakin dense. You claim YOUR OWN car put down 310 at the wheels stock and then keep arguing the SAE rating of 305hp AT THE CRANK for a '01 LS1 is correct?
I have seen at least 3 posted dynos of bone stock M6 '08s putting down 395-400 at the wheels.
Here's another one.
http://forums.corvetteforum.com/show...ght=stock+dyno
An engine that was making 436(Z06 exhaust option) it would dyno 370 at the wheels. There are no '08 M6s dynoing that low unless they're F'd up. The LS3 is a 460-470hp engine.
And before you claim that the dynos are reading high, the M6 LS2 vettes were all dynoing around 340 at the wheels which matches up with the SAE rating of 400hp.
Why would Chevy underrate the LS3? Because Chevy has to move the Z06. It's pretty hard to sell Chevy's halo car for $80K sitting next to a $50K Vette making only 35hp less.
I have seen at least 3 posted dynos of bone stock M6 '08s putting down 395-400 at the wheels.
Here's another one.
http://forums.corvetteforum.com/show...ght=stock+dyno
An engine that was making 436(Z06 exhaust option) it would dyno 370 at the wheels. There are no '08 M6s dynoing that low unless they're F'd up. The LS3 is a 460-470hp engine.
And before you claim that the dynos are reading high, the M6 LS2 vettes were all dynoing around 340 at the wheels which matches up with the SAE rating of 400hp.
Why would Chevy underrate the LS3? Because Chevy has to move the Z06. It's pretty hard to sell Chevy's halo car for $80K sitting next to a $50K Vette making only 35hp less.
BTW the LS1 HP output was not rated to the same standard that the LS3, and LS7, LS9, LSA, etc...are rated to. This allowed GM to unde rate the 4th gen F-bodies. Frankly I just don't see it happening anymore. To much at stake for GM to lie about power output these days. Here is some light reading regarding everything you want to know about the new SAE ratings: http://forums.corvetteforum.com/show...&highlight=SAE
If anything differences in dyno readings from one stock car to the stock car next is more a result of differences in driveline loss (tranny, diff) than the motor. The 08 Vettes do have a new transmission. Maybe it eats up less power. For example my 08 Z with under 1400 miles put down about 20 more HP than the "Average" See here: http://forums.corvetteforum.com/show....php?t=1957144
03-17-2008, 04:52 PM
#22
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Posts: 619
Man you are freakin dense. You claim YOUR OWN car put down 310 at the wheels stock and then keep arguing the SAE rating of 305hp AT THE CRANK for a '01 LS1 is correct?
I have seen at least 3 posted dynos of bone stock M6 '08s putting down 395-400 at the wheels.
Here's another one.
http://forums.corvetteforum.com/show...ght=stock+dyno
An engine that was making 436(Z06 exhaust option) it would dyno 370 at the wheels. There are no '08 M6s dynoing that low unless they're F'd up. The LS3 is a 460-470hp engine.
And before you claim that the dynos are reading high, the M6 LS2 vettes were all dynoing around 340 at the wheels which matches up with the SAE rating of 400hp.
Why would Chevy underrate the LS3? Because Chevy has to move the Z06. It's pretty hard to sell Chevy's halo car for $80K sitting next to a $50K Vette making only 35hp less.
I have seen at least 3 posted dynos of bone stock M6 '08s putting down 395-400 at the wheels.
Here's another one.
http://forums.corvetteforum.com/show...ght=stock+dyno
An engine that was making 436(Z06 exhaust option) it would dyno 370 at the wheels. There are no '08 M6s dynoing that low unless they're F'd up. The LS3 is a 460-470hp engine.
And before you claim that the dynos are reading high, the M6 LS2 vettes were all dynoing around 340 at the wheels which matches up with the SAE rating of 400hp.
Why would Chevy underrate the LS3? Because Chevy has to move the Z06. It's pretty hard to sell Chevy's halo car for $80K sitting next to a $50K Vette making only 35hp less.
03-17-2008, 08:07 PM
#23
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Join Date: Sep 1999
Location: Houston Tx
Posts: 393
Man you are freakin dense. You claim YOUR OWN car put down 310 at the wheels stock and then keep arguing the SAE rating of 305hp AT THE CRANK for a '01 LS1 is correct?
I have seen at least 3 posted dynos of bone stock M6 '08s putting down 395-400 at the wheels.
Here's another one.
http://forums.corvetteforum.com/show...ght=stock+dyno
An engine that was making 436(Z06 exhaust option) it would dyno 370 at the wheels. There are no '08 M6s dynoing that low unless they're F'd up. The LS3 is a 460-470hp engine.
And before you claim that the dynos are reading high, the M6 LS2 vettes were all dynoing around 340 at the wheels which matches up with the SAE rating of 400hp.
Why would Chevy underrate the LS3? Because Chevy has to move the Z06. It's pretty hard to sell Chevy's halo car for $80K sitting next to a $50K Vette making only 35hp less.
I have seen at least 3 posted dynos of bone stock M6 '08s putting down 395-400 at the wheels.
Here's another one.
http://forums.corvetteforum.com/show...ght=stock+dyno
An engine that was making 436(Z06 exhaust option) it would dyno 370 at the wheels. There are no '08 M6s dynoing that low unless they're F'd up. The LS3 is a 460-470hp engine.
And before you claim that the dynos are reading high, the M6 LS2 vettes were all dynoing around 340 at the wheels which matches up with the SAE rating of 400hp.
Why would Chevy underrate the LS3? Because Chevy has to move the Z06. It's pretty hard to sell Chevy's halo car for $80K sitting next to a $50K Vette making only 35hp less.
03-17-2008, 09:51 PM
#24
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Location: TX Med Ctr
Posts: 4,000
That is true. The new SAE standard does layout the test requirements, but I don't believe it necessarily would disallow underrating of engines. However, to be SAE certified you must report within +/- 1% of the power the SAE observer witnesses on the dyno.
03-17-2008, 10:07 PM
#25
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Join Date: Sep 1998
Location: Atlanta, Ga
Posts: 642
Why would Chevy underrate the LS3? Because Chevy has to move the Z06. It's pretty hard to sell Chevy's halo car for $80K sitting next to a $50K Vette making only 35hp less.
Seems to me 10-11% looks a little more accurate figure for drivetrain loss than the 15% it looks like you're trying to use.
Pretty sure a couple of the dyno shops reporting these just under 400rwhp numbers for the LS3 reported some LS2s up above 355 rwhp stock too. I don't see why the drivetrain loss between the two shouldn't be about the same set number. Add on 40-45 hp or so to their rwhp numbers and you get about dead on their crank ratings for each...
Last edited by Ray86IROC; 03-17-2008 at 10:16 PM.
03-18-2008, 12:40 AM
#26
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Location: SeVa
Posts: 2,977
Y'know this thing about factoring in drivetrain loss using a percentage has always bugged me. I'm sure power absorbtion via percentage is accurate to a point, but it just doesn't hold up when power numbers get bigger using a standard correction factor like 15% (or whatever people like to use). I'm sure a powertrain will absorb a total number of horsepower, but given an identical drivetrain behind a more powerful motor it just starts to defy logic. If a 150hp engine took 23hp (15% as an example) or rather 23 horspower was absorbed by the drivetrain and I quadrupled the power why would it all of a sudden take 92hp to turn the same drivetrain, or the inverse, if a drivetrain with a 150hp motor absorbs 23hp to run it and I installed a 75hp motor, why all of a sudden would it only take 11 horspower to turn the same drivetrain? The truth is it doesn't, a particular drivetrain will only absorb a certain amount of power and increasing or decreasing the input doesn't change that total number significantly either way.
03-18-2008, 01:33 AM
#27
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Join Date: Apr 2007
Posts: 619
Y'know this thing about factoring in drivetrain loss using a percentage has always bugged me. I'm sure power absorbtion via percentage is accurate to a point, but it just doesn't hold up when power numbers get bigger using a standard correction factor like 15% (or whatever people like to use). I'm sure a powertrain will absorb a total number of horsepower, but given an identical drivetrain behind a more powerful motor it just starts to defy logic. If a 150hp engine took 23hp (15% as an example) or rather 23 horspower was absorbed by the drivetrain and I quadrupled the power why would it all of a sudden take 92hp to turn the same drivetrain, or the inverse, if a drivetrain with a 150hp motor absorbs 23hp to run it and I installed a 75hp motor, why all of a sudden would it only take 11 horspower to turn the same drivetrain? The truth is it doesn't, a particular drivetrain will only absorb a certain amount of power and increasing or decreasing the input doesn't change that total number significantly either way.
03-18-2008, 05:00 AM
#28
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Location: Knoxville, TN
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Nope, I don't buy the percentage either. IMHO, a typical V8 will lose ~50 HP through a street-style manual transmission drivetrain -whether it is a stock 205 HP 5.0, or a stock 400 HP LS2. Perhaps a bit more with the higher HP, and a bit less with the lower HP, but not double/half.
03-18-2008, 12:31 PM
#29
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Happened only one time with one engine, the '98-02 LS1, and even then, early LS1s didn't have the output of Corvettes.
LT1s had different heads (iron, and more restrictive), more restrictive intake and exhaust (log-type manifolds single exhaust). 3rd gens basically had Corvette style inductions on smaller 5 liter V8s.
What's really silly is when we look at 400 horsepower and blow it off. 400 horses is nothing to shake a stick at. To top it off, we're talking about a mere 25 horsepower difference from the LS2 and what's expected to show up on the Camaro.
Unless you're the type of person who it's a matter of life and death to go 173.05 mph instead of 173.00 mph, that difference is something you aren't even going to notice in a 3700-3800 pound car.
Last edited by guionM; 03-18-2008 at 12:36 PM.
03-18-2008, 01:29 PM
#30
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Yet another 4th gen inspired myth.
Happened only one time with one engine, the '98-02 LS1, and even then, early LS1s didn't have the output of Corvettes.
LT1s had different heads (iron, and more restrictive), more restrictive intake and exhaust (log-type manifolds single exhaust). 3rd gens basically had Corvette style inductions on smaller 5 liter V8s.
Happened only one time with one engine, the '98-02 LS1, and even then, early LS1s didn't have the output of Corvettes.
LT1s had different heads (iron, and more restrictive), more restrictive intake and exhaust (log-type manifolds single exhaust). 3rd gens basically had Corvette style inductions on smaller 5 liter V8s.
Actually you're wrong about the heads on 4th gen Fbod's. The Corvette got 4 bolt mains and Aluminum heads. The F-body cars got 2 bolt mains and aluminum heads.
The '94 - '96 Buick Roadmaster, Cadillac Fleetwood, Chevrolet Caprice, police cars and the Impala SS got the 5.7L with 2 bolt mains and cast iron heads.
