The out-turn weight of the BMW conversion has not been formally determined
thus far. Only to say that the engine (complete with starter,oil cooler,
alternator, throttle bodies, but NOT the exhaust ) weighs in at 61Kg and
the gearbox weighs 15Kg. To this you will need to add the weight of the
exhaust, oil and inlet airbox.
If an installed 912 weighs 175lbs (sorry to mix units) then the BMW looks
like being very close to this. Too close to say at this stage whether it
will be the same or marginally heavier.
In terms of additional power, remapping of the engine management easily
takes power beyond 100hp; this has been demonstrated on standard engines
used in endurance racing and suceeds simply by tipping additional fuel into
the engine (it is currently optimised to provide acceptable emissions
rather than maximum power) and by reducing the factor of safety on
detonation built into the ignition timing (which is for the purpose of
allowing the use of "minus 2 star" petrol in those countries where there is
no option).
Of greater long term interest is the response of the engine to turbo
charging; a mild half-bar boost would see power up to about 150hp (which is
the limit to which the speed reduction gearbox has been designed). The
engine has been shown by others to be capable of 2 bar boost and 280hp (the
Arrows Formula 1 team do this to them for the purpose of chassis testing in
place of the rather more expensive Yamaha V10`s). However, it is the
ability to handle thermal loads (as opposed to mechanical loads) that is
the limiting factor for our type of use and in this respect the engine
shows promise.
Duncan McFadyean
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