what tuning are you thinking about? There's not a whole lot to tune on these drivetrains..Now I'm thinking of updating it a bit, replacing some elements, and doing a little tuning. I took it for get at work, but I think I won't invest much.
I am not sure that the goal was "reduce the propulsion torque" so much as "reduce the speed that MGB needs to spin". MGB is perfectly CAPABLE of driving at full speed but if it can do so at lower RPM, that's more efficient.Similar to the "reduce generator fuel consumption per distance driven" goal accomplished by clutching MGA to Gen 1's ring gear when cruising down the road while extending the range - MGB no longer provides 100% of the propulsion torque, so less generator output power needs to be created per mile driven, so less gas is burned for that function, and "gas" mileage is improved.
I fully agree that the "engineering" goal was to reduce MGB’s rpm to improve efficiency, same as when it happens in Electric Mode. With no "direct path from engine to wheels" (engine functions only as a generator), the Gen 1 Volt is a fully electric car capable of being driven using electric propulsion only for 300+ non-stop miles. But without the help of the engine’s torque, gas mileage would have dropped. And "BEV" purists would still have refused to view a gas-generated electric powered car as a "real" electric car.I am not sure that the goal was "reduce the propulsion torque" so much as "reduce the speed that MGB needs to spin". MGB is perfectly CAPABLE of driving at full speed but if it can do so at lower RPM, that's more efficient.