The MAF would precisely match the fuel ratio with the air flow for efficiency and performance. Hence less air flow = less fuel, more air flow = more fuel. The claim of the Hiclone is to improve efficiency by introducing a vortex to improve the mixing of the fuel within the combustion chamber. Hence the vortex needs to be present in the combustion chamber at the time of fuel injection to get any gain in an injected engine. To get this on a diesel such as the TD5, I believe you would need five of them, one on each of the inlet manifold ports!
Trev.
