Diesel tuning? Beware of cubic milimeters!

A common mistake in calculating the correct diesel ECU maps is failing to notice that the injection timing map (alternatively - injection duration) has the engine load axis scaled not in mg/cycle, but in millilitres/cycle (cubic millimetres). Since diesel fuel's density is less than that of water, one litre of diesel fuel weighs less (0.82kg) than one litre of water (1kg). By ignoring this fact and treating millilitres as milligrams, we are making a significant error. Some tuners know this, but claim that it is not a big difference when millilitres are treated as milligrams. However, this is an illusion. The error is (100/82)*100% = about 20%. Very bad :( Such an assumption means that the tuned, modified injection will start at a lower engine load, and we haven't added air then, because the boost pressure map has the load mostly just in mg/cycle (or in Nm). To correct this, remember to check the Damos/A2L files for the load unit in the Duration map. EDC17 is mostly in millilitres, and MD1 is already in milligrams (but not all). If you notice that they are, however, millilitres (mm^3) then instead of a factor of 0.01 (as for mg) enter 0.0082 and you already have milligrams. Simple and effective. Use this and you will avoid momentary smoke when kicking the accelerator, resulting from a lack of air for the increased fuel dose. Good luck!