Lt1 camaro is 275 horses, ls1 camaro is 315 horses, Z06 corvette is 405 horses. My question is, is that hp rated at the wheels or at the flywheel?

 

Flywheel.

 

Do all car manufacturers rate there horsepower like this? If you consider a 15% power loss from flywheel to Rear wheel hp, a Z06 corvette makes only 344 horses? and my car got dynoed today for 340 horses so that means I am making almost 400 horses at the flywheel same as Z06. Is this right?

 

Yes all manufacturers publish flywheel horsepower. Rear wheel cars have somewhere between 10 - 15% drivetrain loses, depending on whether it's an automatic (more loses) or manual tranny.

 

All manufacturers are required to rate their engines in "SAE net HP".... at the flywheel. The engine is put on an engine dyno, with full intake and exhaust and all "standard" accessories, as it would be installed in the car, and tested.

Their is no fixed value for drivetrain loss. I've dyno tested my setup on both an engine dyno with full intake and exhaust, and then on a chassis dyno. When the car was an M6, the losses ranged from 12.6% when starting with 500flywheelHP to 12.2% at the 800HP level. When the setup was converted to a TH400 with a loose, non-locking convertor, drivetrain losses increased to 19.8% at the 500flywheelHP level, to over 21% at the 800HP level (300-shot of nitrous).

Your engine would probably be rated at about 390flywheel if you are running the T56, and 410flywheel HP if you are running the 4L60E. Of course that assumes that your chassis dyno was "SAE corrected" to SAE standard temperature, barometric pressure and humidity.

 

So the 340 horsepower that i am reporting is at the wheel and the 405 horsepower that the z06 reports is at the fly wheel? and lets say that I am making 390 at the fly wheel that means I am about 15 horses away from the z06... WOW! sorry to be a little repetitive I just wanna be sure and I'm a little excited that I am making almost as much power as a vette... Thanks

 

haha, congratulations! Now the question is are you making the same kind of power? The newer LS1s are pretty flat torque wise, while your engine might be a bit more peaky and not have as strong an accelleration curve as the Z06.

Don't assume that an automatic is less efficient accellerating down the track. While an auto will show high losses with a loose converter on a chassis dyno, especially on the bottle : ) fact is the quickest super stock cars are almost all automatics- class wise. There is a reason that the 4 speed "dropout" transmission was developed for nascar. Testing showed a roughly 75 hp loss through a race prepped jerico in 4th at race rpm. By dropping out the cluster shaft in 4th much of the power was recovered. Think of all those rotating gears in a T56.