A free app for Android, by JoshKW.
This is a free, fun, and educational app that allows you to do advanced math calculations and simulations. You can use this to calculate 1/4 mile times, exhaust and pump sizes, and many other characteristics of your engine.
There are lots of questions you can answer. You can get the answers for any engine and weather condition. If you don't know the answer, you can try to calculate it.
You can also get the answers for different driving conditions. You can choose between different settings, such as boost, tires, and exhaust.