Cold Boosted SAE Horsepower!

[rosulekg]

The SAE horsepower calculator Engine Tuning Calculator - dew point doesn't make any distinctions between normally aspirated and boosted. I'm guessing dense air compressed makes torque, and that is what were feeling, and the SAE horsepower would be the same relative amount. Am I right?

[RocketSled]

I'm not even sure what you're asking. But...

This calculator can only be used for normally aspirated engines. The rules change with a boosted engine, since the density of the air going in to the engine is a function of the specifics of the compressor being used, more so than a function of the ambient atmospherics (air temperature and pressure and humidity still matter to a forced induction system, but to a substantially lesser degree than an engine that has to breath normally. That is in fact one of the key benefits of a Supercharger, it reduces the engine's sensitivity to atmospheric conditions).

As for the question about torque, no denser air does not make more torque. The PCM attempts to maintain an optimal air/fuel ratio to maximize power. As the air cools off and density increases, the stroke of each piston brings proportionally more air in to each cylinder. The PCM "sees" that more air is coming in to the engine and it responds by adding more fuel. As a result, you get more power because you're burning more gas.

A supercharger does the same thing. It puts more air in to each cylinder with each intake stroke, and the PCM adds more fuel in proportion to take advantage of the additional O2, and the result is a bigger explosion on the power stroke and so, more power.

[rosulekg]

Thanks Rocketsled!
So 42lb inj. good for 560RWHP is relative to the compressor and is a case by case.
I need to find out what my 02 Z06 with STS and 42's is good for max..