xpensive wrote:231 g per kWh is an efficiency of xactly 33%, which means the 2014 engines would produce only 433 kW (588 Hp) at 27.8 g per second with the same efficiency, why I hope the KERS/HERS will contribute in a serious fashion?
Tommy Cookers wrote:The Turbo-Compound (as did many engines of this generation) had an artificially low compression ratio, to allow very high max MEP and power by allowing very high pressure supercharging, so the exhaust emerged at relatively high pressure. This was why they had the turbines (unlike other versions of the same engine).
I can't see how this avoids the significant losses around the valve and before the turbine, but I'm open to being proved wrong. Does the higher overall pressure in the forced induction engine at this point make available the turbine some of the pressure drop that would otherwise be wasted ?
I know there's a lot about feeding exhaust pulses to the turbine; but after 80 years of viable turbocharging we still don't have clear statements/measurements showing what goes on IMO. Such pulses could equally be called low amplitude explosions whose energy (partly) decays before it can be used ? Explosion means supersonic/shock conditions that degrade and can't be conserved.
In racing we harvest exhaust pulses after degradation via our exhaust system design with naturally aspirated engines (to increase mass flow/MEP, ie some 'free supercharging'); one revelation of the F1 turbo era was that turbos need exactly the same exhaust system design ?
Tommy Cookers wrote:'fuel for thermal management to prevent detonation'
Tommy Cookers wrote:A rich mixture has a beneficial effect re. detonation that is independent of thermal effects (of course thermal effects are a symptom of a rich mixture, and are also useful).
Tommy Cookers wrote:Avgas was designed and made for a particularly large benefit with rich mixture (about ten times better than pump fuel), and still does this today.
Maybe track use is kinder re. detonation to any type of engine than the worst road use would be ?
Tommy Cookers wrote:Anyway, 1000 bhp sounds good ! Thanks for the information.
Tommy Cookers wrote:Thanks for the information !
My issue is with the FIA.
They talk a good act (of greeness/road relevance), but the 2014 rules allow only 1 design approach to this. This favours an expensive product mix ( the 200 bhp road car that is 'all-electric' in town), F1 will be a constant advertisement for this.
My interest in the turbocharger is how much of its drive is recovery from what is wasted in the exhaust of the NA engine (also this is related to compounding), and how this compares with engines (10 million and rising?) that have greater expansion before exhausting.
I can believe that the turbo engine can be more efficient than the NA engine even without any recovery from exhaust at NA exhaust state.
pgfpro wrote:Keep in mind that the 231g/kWh BSFC numbers I speak of are on engines that were produced over 20 years ago and were OEM passenger engines design originally at only 135HP to 200HP. IMO I think that a purposely built turbocharge race engine ie. with all the new technology, F1 will have BSFC numbers around .30 lbs/hr or 182 g/kWh BSFC to produce around 741HP.
Q: Under race conditions what does the engine do MPG wise?
On the dyno it does 230g/kWhr... there is virtually no petrol road car that makes horsepower at that small a fuel burn... on the race track it equates to around 12 miles per UK Gallon; it doesn’t sound that good but that is actually an impressive number; about double what the petrol LMP1 cars will get.
To obtain the best fuel consumption at 2.5Bar Honda found it necessary to run a charge air temprature of 70 degrees centigrade and a weak mixture -an air ratio off 1.02 - and a fuel temperature of 80 degrees centigrade. Under these conditions Honda was able to produce an extremely frugal race engine having a brake specific fuel consumption of 264 g/kWhr at 12,000rpm and giving a maximum power of 620bhp a 12,500rpm.
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