Carburetor to Hotwire EFI conversion
Basically the twin SU HIF6 carbs are not bad at all. I have the impression that they are probably the best option for the humble 3.5 liter with regards to torque. All other options to supply the air-fuel mixture will see an increase in flowpotential. This sounds good, but for low down torque you're not looking at max flow potential - you're looking at high airspeed at low revs. So basically a slightly restrictive intake might do just that.
Anyway, my engine has been fitted with 9.75 cr pistons and SD1 heads, so what can we do to get more out of the same engine? While at the same time I would like to keep my current (excellent) fuel economy, and at the same time get rid of the almost yearly adjustment of carbs. There are two options: fuel injection or the Weber 500. The Weber is still a carb (though a very good one), but I felt that fuel injection was the way to go. Looking at Roger Parker, Mike Barnfather, Marc Gander and some others gave me the impression that it was feasible. After some discussion with LPG fitters I definitely made the decision to go EFI. LPG would function better with the "open" system as provided by an EFI system.
So I bought myself a Hotwire EFI system of a LandRover 3.9 from 1992. It included everything I needed: ECU, wiring loom, injectors and the like. It looked impressive and I had no clue what belonged where. You can imagine how glad I was when Roger Parker at the MGOC Headquarters provided all details!