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Isn't this a repost?
 

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Still playin wit the fan site...got a make-shift forum up and running!

Wow, it's late...guess it's time for bed!!!

All the "other" dealers went to bed.... Go figure!
 

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I thought modern factory numbers were net, so wouldn't that mean they measure it at the drive shaft or something like that? I thought it was gross ratings from '71 and before or somethin like that that were from the flywheel or crank or somethin? :confused:
 

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So factory horsepower rating is supposed to be around 426, but the only dyno i have seen the SS camaro dynoed at 364 is there really a 64 horsepower loss just through the drivetrain thats a pretty big leap between numbers. I know factory numbers vary from actual dynometers but really?? Check out the link and let me know some input. I know that is still quite a few horsies but I may just be bein greedy.

http://www.youtube.com/watch?v=PN2GGzlX0QE

Also, this was an awesome all around, to the point, consise and pretty informative video going over the three new pony cars. Check it out too!

http://www.youtube.com/watch?v=r-uTjaQ6E7g

Thanks!!:thumbsup:
Yep, those have been posted here once or twice, that HP loss seems pretty standard. GM seems to be not underrating their motors like they once have :D
 

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:werd:

Oooh.......OUCH! Didnt think the manual made that much of a diff. Shoot I woulda had knee surgery if I knew that lol!
^^^ It's not the transmission, it's then engine itself (I suspect you knew this but just for clarity...)

The manual comes with the 430 HP LS3 and the automatic comes with the 400 HP L99 (w/ variable valve timing and automatic fuel management.) I think you'll be very happy with it (and I suspect the only 400 HP L99s are gonna catch a lot of LS3s off-guard at the lights...)
 

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I thought modern factory numbers were net, so wouldn't that mean they measure it at the drive shaft or something like that? I thought it was gross ratings from '71 and before or somethin like that that were from the flywheel or crank or somethin? :confused:
"Net" meant "with all the accessories" -- stuff like water pumps, alternators, fans, etc. that cause drag and that that weren't required under the older "gross" rules. Even so, however, there were no hard-&-fast proscriptions about the actual testing regimen, which meant fudging the numbers was the norm. A few years ago (someone will chime in with when), the SAE published very specific guidelines for measuring engine output and most manufacturers complied, providing the first "accurate" power numbers for new cars and also providing, for the first time, a meaningful comparison between different cars, whether from the same or different manufacturers.

FWIW...
 

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If I owned a speed shop I might be tempted to fudge the numbers so that they appear lower in stock form, then when the car is modded it would appear as if my mods made even more additional power than they normally would have.

There are many ways to alter chassis dyno #'s.

I'm not saying this is what happened with this particular car, but the numbers do seem a little low compared to stock LS3 Vette dyno numbers imo.
 

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If I owned a speed shop I might be tempted to fudge the numbers so that they appear lower in stock form, then when the car is modded it would appear as if my mods made even more additional power than they normally would have.

There are many ways to alter chassis dyno #'s.

I'm not saying this is what happened with this particular car, but the numbers do seem a little low compared to stock LS3 Vette dyno numbers imo.
It's because it is a Camaro and not a Corvette :D
 

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Soo...the Vette with 4 more flywheel hp makes 30+ more rwhp just because it's not a Camaro? Redline Motorsports has dynoed several 09 Vettes with over 400 rwhp stock.
 

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I just realized Livernois uses a Mustang chassis dyno. That explains the lower #'s. Mustang dyno's typically read 20-25rwhp lower than a Dynojet. In other words that same car would probably make 385-390rwhp on a more commonly used Dynojet.
 

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^^^ It's not the transmission, it's then engine itself (I suspect you knew this but just for clarity...)

The manual comes with the 430 HP LS3 and the automatic comes with the 400 HP L99 (w/ variable valve timing and automatic fuel management.) I think you'll be very happy with it (and I suspect the only 400 HP L99s are gonna catch a lot of LS3s off-guard at the lights...)
OK, here I go again with my dumb questions... why does the L99 get 26 less horsepower at the crank than the LS3? I thought they were essentially the same engine.
 

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Soo...the Vette with 4 more flywheel hp makes 30+ more rwhp just because it's not a Camaro? Redline Motorsports has dynoed several 09 Vettes with over 400 rwhp stock.
Obviously not, there was a bit of humor in my reply ;) They may be tuned slightly different from the factory etc. GM does not have a long history of having other vehicles produce more HP than the flagship Corvette :D
 

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OK, here I go again with my dumb questions... why does the L99 get 26 less horsepower at the crank than the LS3? I thought they were essentially the same engine.
The focus of the L99's VVT appears to be increased charge efficiency (that is, attempting to maximize extraction of potential energy from the fuel-air "charge", not the battery-related efficiency I just posted about in a different thread!) across the operating RPM range rather than (and, to an extent, at the expense of) the peak-power RPM range at which VE (volumetric efficiency) is naturally high. In essence, the are trading a little HP for a broader torque curve but get remarkably similar "areas under the curve" or total power delivery capability. This is a very intelligent approach, too, IMHO.

The L99 has a slightly lower mechanical RPM limit, I'd assume due to harmonic issues, but appears to be "cammed" to have run out of steam by then anyhow. It will be very interesting to see what the more technologically sophisticated aftermarket folks will do here (and I do NOT mean the troglodytes who will advocate ripping VVT out...)


NOTE: The attentive reader will observe that I sneakily tied in the topics of two technical threads I have started elswhere on the forum. :)
 

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The L99 has a slightly lower mechanical RPM limit, I'd assume due to harmonic issues, but appears to be "cammed" to have run out of steam by then anyhow. It will be very interesting to see what the more technologically sophisticated aftermarket folks will do here (and I do NOT mean the troglodytes who will advocate ripping VVT out...)
...
Did someone say, "cam-swap"? :popcorn:
 
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