Horsepower and Torque: View horsepower and torque in graphical format
This performance analysis tool, SpeedTracer, has many built-in vehicle profiles and uses the SAEJ1349 standard for environmental variables (humidity, elevation etc) for dynamometer correction. The SAE formulas are designed for normally aspirated vehicles. This tool goes one step further and corrects for force induction as well. Without these corrections your torque and horsepower readings would be inaccurate from day to day and region to region.
SpeedTracer makes inputting your vehicle profile easy because it has most vehicle profiles built into the software. If your vehicle's profile is listed, you won't have to manually input the values--it is already done for you. If you have made special modifications to your vehicle, you can change your vehicle profile to take those into account. You can also create and modify vehicle profiles to suit your needs.
You can use this tool to see the effect on performance when new parts are added to a car.