After strugling for hours to get a new nitrous controller and powertrain I finally figured it out by reading at line 1775 in combustionEngine.lua that there is a similar function to nitrous as there is to turbos

turbochargerLuaFileName is well known within the community but I found

nitrousOxideLuaFileName

Might seem obvious but it sure wasn't for me lol

if you google "nitrousOxideLuaFileName" Not a single result shows up where someone mentions it.

-By Adam, Revolution Racecraft