Hand calculation

A recurring theme in my Racecar Engineering articles over the years has been the importance of hand calculations. Sadly, this is a discipline that has been atrophying.

The purpose, therefore, of this article is to highlight what I consider to be the most important hand calculations any performance / data / race engineer has to have at their fingertips.

Downforce

The first example I want to discuss is hand calculation of downforce. I realise that for some of you reading this, the feeling here could very well be exasperation, but it blows me away the number of professional race engineers I meet who not only can’t do this, but think it is impossible.

What I am about to show needs to be one of your first go-tos, particularly if you are dealing with an aero car.

The language of aerodynamics is CLA, CDA and aero balance. Mathematically, this is expressed as Equation 1.

Here, is the inline acceleration, is the engine torque in Nm, is the gear ratio (in terms of torque multiplication from engine to is the rolling radius of the tyre and are the individual spring forces that are in N.