Re: FITCH motors...
Actually, the FICHT and E-Tec systems are very similar, although BRP would probably not like to have them associated.
First off the Ficht system. It is a direct injection system meaning that the fuel is injected directly into the combustion chamber when the piston is close to the top of its stroke. This concept is great for fuel economy, power, and emissions, but there are technical challenges with injecting fuel into a hot, highly compressed combustion chamber.
The Ficht system injects the fuel by energizing a solenoid that serves as a plunger. The plunger pushes on a column of fuel that is piped to an injector. So, the order of operations is that an electric current is sent to a solenoid which causes a plunger to push fuel into the combustion chamber. The plunger is returned to its original position by a spring. When the plunger is pulled back to its "rest" position, it is re-filled with fuel ready for the next cycle.
The big difference between Ficht & E-tec is that there is no spring in the E-tec system. The plunger is returned to its "rest" position by reversing the current through the solenoid which makes the plunger shuttle in the opposite direction.
The reversing polarity design does have several advantages to be sure, including the fact that the plunger can return to position faster, and it is quieter than the old spring system.
The E-tec system allows greater control of the solenoid that the Ficht system did, in fact my understanding is that during some running speeds and loads, the computer does not allow the plunger to travel its entire stroke, i.e. the current is reversed pulling the solenoid back. This allows the computer to not only control when the fuel is injected, but how much fuel is injected.
I suspect that the biggest advantage of E-tec over Ficht is the fact that lessons learned during the development of the technology were applied and the bugs of the system were worked out. The newer FICHTS are supposedly better than their predecessors, but cant say for certain. I do know they are a bugger to work on for the common back yard hack like myself, without any computerized analyzers.
