Engine
Sensors, ignition, fuelling and the mechanical side of making one run.
Density altitude and dyno correction
How much air there is today, why a hot damp day at sea level is worth thousands of feet of altitude, and what the difference is between an SAE number and a DIN one.
Lambda, AFR, and what the gauge says
Three ways of writing one mixture, and why a car on E85 at a perfectly good lambda reads 12.1 on a wideband — both numbers correct, only one an air/fuel ratio.
Sizing a turbo from the compressor map
Work out the mass flow and pressure ratio your engine will actually run at — the two axes of every compressor map — then take that point to the maps of the turbos you are choosing between.
Estimating horsepower from airflow
An engine makes power in proportion to the air it can pump. Working from that gives an estimate you can argue with — unlike a multiplier for 'large turbo'.
Compression ratio, and how to work it out
Static and effective compression from bore, stroke, chamber, dish, deck and gasket — with the formulas written out, and a calculator that applies them.
Sizing fuel injectors
What size injectors a target power needs, what they really flow at your fuel pressure, and why the same set that was fine on petrol is marginal on E85.
Gearing: road speed, rev drop and tyre size
How gear ratios, final drive and tyre diameter set road speed, and how to read the rev drop between gears — the number that decides whether a gearbox suits an engine.