Liam.Owens wrote:I am wanting to understand how the 2014 regulation changes concerning the new 1.6ltr V6 turbocharged engine is more efficient than the current V8.
How does a turbo affect the engine efficiency?
How does reducing the maximum revs from 18,000 RPM to 15,000 RPM effect efficiency?
Obviously the new fuel regulations are understandable, the ERS regulation makes simple sense.
Thanks, Liam.
the current engines are the product of 100 years of rules that aim to limit power only by engine capacity (not by fuel quantity)
so they have a very large bore and a very small stroke, to displace 2.4 litres of air as fast as possible ie 18000 rpm
so make more power via this high rpm
than they lose via efficiency (ie fuel consumption) being quite poor, because .....
the large bore and related combustion chamber surface area cause unusually high heat loss to coolant
friction eg from piston/cylinder is similarly high due to these proportions and high rpm
the average fuelling (deliberately allowed by the over-generous tank size) is about 15% more than can be burnt with the available air
the new engine rules require a smaller bore and lower rpm
together these contribute towards reducing the proportionate losses to coolant and from friction
also the rules require turbocharging integrated with electric turbo-compounding
this forces a smaller capacity ie an additional reduction in the proportionate losses to coolant and friction aka 'downsizing'
if there was a reduction in compression ratio necessary with this turbocharged induction pressure
the associated reduction in piston/crankshaft power would be compensated by increased power recovery aka 'compounding'
and the advanced DI will help CR by fuelling only microseconds before ignition
so there would be a significant 'relevant' efficiency gain from this combination (about 20% of the usual efficiency)
but advanced DI and turbocharged downsizing are already here in mass produced road cars
the 2014 F1 is unique only for its power recovery by electric compounding, this gives a gain of about 10% of the usual efficiency
(2014 F1 does not try to recover energy wasted to coolant, this is 'road relevant' according to BMW and GM research)
actually the CR will also remain high because the F1 fuel rules IMO now have unlimited Octane number
and the fuel will also be tailored for best specific energy by weight
efficiency gains from changes in fuel and fuelling should be discounted as not 'road relevant'
BTW thermal efficiency x mechanical efficiency = overall efficiency (aka brake thermal efficiency)
often European sources mistakenly write in English TE when they mean BTE
40% TE is not remarkable, but 40% BTE is