I've just finished my horsepower calculator and am looking for input. Since everyone I know who knows C/C++ doesn't check their emails for a week or so, I thought this was the most efficient route for getting feedback. The source is attached and needs to be compiled (It works in both MSVC++ .NET and DevCPP 4, so it should compile for most other compilers).
It works on the premise that the user is finding the output at the flywheel and that they are finding both the horsepower and torque (foot-pounds) at a specific RPM output (meaning that the numbers won't match up exactly to factory-rated specs because normally the torque peak is at a lesser RPM than the HP peak is). I'm thinking about doing more calcs for different engine dynamics based on what I get here, so please don't hesitate to give your input.