Using mathematics to correctly design an engine build is not that hard to do. At the very basic level, easy formulas can help you select the perfect turbocharger or fuel injectors for your application. If you wish to go deeper and deeper, math models could allow you to calculate a basic ignition timing map (which should then be perfectioned on a dyno) or fuel map (which would then be checked with a wideband).

Actually, scientist and engine developer spent a huge amount of time behind the math models before producing the engines we love today.

Benefits of using mathematics before designing an engine build:

What are the benefits of using maths applied to engine physics before attempting an engine build?

  • Select the proper size injectors;
  • Select the proper clutch for estimated Torque output;
  • Select the proper turbo if it’s a turbo build;
  • Select proper intake and exhaust tubing size;
  • Save a lot of money buying just 1 product that you already that will work before buying 3 or 4 sizes before discovering it’s not suited for the application;
  • Avoid blowing engines planning the correct air fuel ratio;
  • Easy troubleshoot of MAF and MAP sensor calibration problems.
  • Avoid turbo overspin.
  • Endless list of benefits which I am not thinking about now.

So, did I motivate you to study engine physics? 🙂

Basic of fuel injection calculations:

Since online there are a lot of resources, but usually these are in different websites and articles, I decided to make my own Excel spreadsheet in order to contain everything in one file for the easy calculations.

This is the utility I use the most. Basically everytime I need to remap an ECU or I start a datalog session on a car, or even when I look at a pair of injectors or a turbo online, I open my excel spreadsheet.

Please, before downloading my utility, keep in mind that:

This is the result of my hard work and study, to develop and test the formulas on this Excel spreadsheet I spent A LOT of time. If you can help me to integrate or correct these formulas, please DO! I beg to learn. Also please do not redistribute my work without asking me PLEASE!

You can download my fuel injection calculator from my drive:
Download here

This will cover the basics of fuel injection. Use of it should be straightforward, the info about the Engine should be added in the light green cells, then the calculations take place automatically.