See my first article for a short review and teardown: http://hackcorrelation.blogspot.de/2016/02/inside-stuff-racechip-car-tuning-thingie.html First off let me start by saying I consider this fair use, as the instructions and website do not explain what the settings do, how the unit actually functions and what effects it can have. The description below refers to a single-channel Diesel engine (single common rail). Settings First off, most of the users will just want the simple explanations, here's a graph that should be in the manual: The chart above shows 4 possible settings and their effects. The first rotary encoder controls how much 'extra power' is requested. See 9E vs. BE vs. 4E The second rotary encoder controls the RPM high range (endpoint). See BE vs B7. The encoders go from 8 (minimum) through 9, A, B, C, ..., F, 0, 1 ... 7 (maximum).
Electronics and programming interspersed at various levels of difficulty.