LT4 LT4 Horsepower

[jcs44]

There have been a number of threads over time about what the "real" hp and torque is for the LT4 motor. We all believe 330hp and 340lbft is low. I've noticed that you can buy an LT4 crate motor from GM and they advertise that one at 375hp and 396lbft so this ought to be a strong clue. The basic specs for the crate motor are the same as in our cars. The crate motor comes without the fuel system. Does anyone know what the differences might be?

Thanks,
JCS44
96 LT4 Vert, triple black

 

[Tuna]

If memory serves, the crate motors are advertised at "brake" horsepower not "SAE Net" HP. The crate motors are run bare on a dyno.
Installed HP (SAE Net) takes into account all the stuff and junk hanging onto the motor and the installed inlet system and exhaust.

So, it's comparing apples and oranges again.

 

[bradslt5]

the fuel inj. cars will have more tq in the low and midrange than a carbed motor the hp will be close but the hp will also be greater in the low and mid range on the inj. car due to better fuel metering with the computor