[DarkneSS]

I read an interesting post in a thread on here with someone asking how to get his LS3 up to 500 crank HP. Someone replied with this:

"OK, seriously?
I don't think you understand how this whole thing works.
Most mods out there will not give you horsepower.
They may free up horsepower that is robbed by the powertrain, due to entropy inherent to any mechanical system.
The LS3 itself, under ideal, laboratory conditions (which is probably with NO headers, and NO intake) is rated at 426 at the crank.
Without specifically adding power to the formula, the best you could ever hope to get, in a perfect universe without friction and entropy would be 426 RWHP. Most of these mods will not really increase your crank HP, they will simply reduce the parasitic loss, and bring your RWHP number closer to your crank HP number."

This seems to go completely against my understanding of engine mechanics.

If I add bolt ons to my engine, am I making more crank horse power? I was under the impression that I AM. I've never heard that something like headers doesn't increase crank HP. If you increase wheel horsepower are you not also increasing crank horsepower?

Hence why the LS3 in the Vette is rated at 10 more CRANK HP than a Camaro's because it basically has a cat back.

"The LS3 V-8 is the base engine for the 2010 Corvette and the new Camaro SS. In the Corvette it is rated at 430 horsepower (321 kW), or 436 horsepower (325 kW) when equipped with the optional dual-mode exhaust system (RPO NPP)."

The reason I'm asking is because people were agreeing with this person and a Google search isn't really helping my question.