Providing the design has achieved a positive pressure differential during overlap.
If a design doesn't achieve positive pressure differentail during valve overlap, it is not a racing engine design.
There is not agreement on whether the current F1 engines achieve positive pressure differential. It may be more effective to increase the exhaust pressure beyond that point to increase turbine and MGUH recovery.
Valve overlap increase back pressure, spooling sooner. The bigger the turbine, the more aggressive the cam needs be. Shooting for peak HP, the lower the turbine pressure the better, for peak power a pressure ratio of 1:1 or even better pressure ratio, high overlap cams like NA engines are preferred.
All four F1 engines use a twin scroll turbine.- (quoting from Garrett) ''because of it's superior scavenging effect. A twin scroll turbine have better distribution in the exhaust parts and more efficient delivery of exhaust gas energy to turbine. This in turn allows greater valve overlap, resulting in an improved quality and quantity of the air entering each cylinder, in fact with more valve overlap, the scavenging effect of exhaust flow can literally draw more air in the intake side while drawing out the last of the low pressure exhaust gasses''.
Peak HP on a current F1 engine is crankshaft power plus turbine power minus compressor power. It is possible that the best output comes with exhaust back pressure significantly higher than intake manifold pressure hence my original comment.
Peak HP on F1 engines (turbo hybris) since their introduction is ICE power + K and H sharing battery power, with turbine freewheeling on compressor/H shaft. When no exhaust is involved with turbine.
Last edited by saviour stivala on 03 Apr 2023, 07:45, edited 1 time in total.
Peak HP on a current F1 engine is crankshaft power plus turbine power minus compressor power. It is possible that the best output comes with exhaust back pressure significantly higher than intake manifold pressure hence my original comment.
Peak power (as can run continuously at that power) less 'H' involvement, neither involved with compressor nor with 'K'. (supplying turbine power to nether) As if 'H' is supplying turbine power to either compressor or 'K' It is sharing turbine power with compressor because it will be in generator mode. Repeat:- ''Shooting for peak power, the lower the turbine pressure the better''.
Last edited by saviour stivala on 03 Apr 2023, 11:38, edited 1 time in total.
Peak HP on a current F1 engine is crankshaft power plus turbine power minus compressor power. It is possible that the best output comes with exhaust back pressure significantly higher than intake manifold pressure hence my original comment.
On re-reading your post (exact warding) I am in agreement that ''Peak HP on a current F1 engine (Turbocharged ICE) Is crankshaft power. But I will repeat (my disagreement) 'Because the F1 engine (ICE) is turbocharged, shooting for peak power, the lower the turbine pressure the better. In short, if a compressor can reach full boost with less turbine exhaust gas pressure the more the peak HP output. This is clearly and factually reflected by the 'power unit' running in electric supercharging mode where no exhaust is involved with the turbine (free load mode).
... In short, if a compressor can reach full boost with less turbine exhaust gas pressure the more the peak HP output. This is clearly and factually reflected by the 'power unit' running in electric supercharging mode where no exhaust is involved with the turbine (free load mode).
electric supercharge power is not a measure of the power that the PU makes for 100 kg/hr of fuel
because it includes power made from stored electricity that cost previous fuel - taking fuel total rate over 100 kg/hr
fairly counting the PU power ie at 100 kg/hr true fuel rate .....
how wouldn't the PU compounded make more power than the PU uncompounded ? .....
In electric supercharging mode power output peak as well as in ICE+ELECTRIC power output peak mode "as can run continously'' (actually for a time of 33.33 seconds over one lap), In both these modes the ICE is runing at maximum fueling allowed (100kg/h). Also in both of these running modes the ICE is of course being compressor boosted. In one the compressor is being powered by the 'H' and in the other it is being powered by the turbine, where 'H' is not involved, as if 'H' is involved the compressor will be sharing turbine power with 'H'.
The peak power of the power units measured at the crankshaft should still be when the wastegate is open; not sure where this discussion of semantics is stemming from. The harvesting modes needed in order to achieve this won't be producing more crankshaft power.
Yes. The maximum peak power the power unit can produce is when runing with waste-gate open.
In both harvesting modes, under braking by 'K' or by turbine powered 'H', The power unit cannot be producing any peak powers.
