quote:
Originally posted by imperialdataI understand there are 2 approaches to twin engine design.
1. Drive the rear wheels with engine (a) and the front wheels with engine (b)
2. Use both engines’ output to drive a common gearbox
How the hell does option 1 work, is it totally reliant on electronic engine management? Seem to remember a split gearshift on a Tiger Seven replica which allowed each engine to be gearchanged separately but there must be more to it than that.
All twin BECs (except the bike engine derived V8s..) still retain the original gearboxes – hence the split gearlevers. This applies to 4WD and RWD variants.
To the best of my knowledge all the twin BECs have a split gearchange like mine. You need this to recover from missed shifts or false neutrals etc..
Option 1) requires an electronic “centre diff” to reduce power to the front wheels in order that the car can turn into corners properly – and is very expensive.
Option 2) requires a “transfer box” to take the output from the 2 bike gearboxes and combine. This box sits just behind the engines, at the front of the transmission tunnel. It has 2 inputs and one output which goes, via a propshaft, to the rear diff. This is cheaper than the electronic centre diff – but still not cheap due to it’s “bespoke” nature.