View Full Version : How does GM put a HP rating on there engines?

07-19-2011, 05:08 PM
So I'm looking to get the LS376/480 crate. But I want to know from a techical stand point that if this crate is rated at 480hp. What dyno test was done to achieve that? Was it dynoed with long tube headers? Were there accessories involved? I think is a great platform to start especially on a budget. So I would like to hear from sponsors and techs!

07-20-2011, 11:16 AM
Our baseline horsepower and torque ratings are based on testing with the
production-style, normally aspirated injection system. There’s no telling
how much power you can realize with a carefully tuned turbo or supercharger
See page 286 for information on our reference guide P/N 88959384 for installing

This statement is directly out of the GMPP 10 catalog. I think they test them with factory manifolds and stock accsy. such as the water pump and alt. I doubt they have power steering pump or ac compressor on them. Its a bad little motor. I want the 454 crate for my HD truck.