Sorry some of the numbers didn't transfer over from the spreadsheet.
344 ft.lbs/ tq @ 8000rpm 76 kg/hr limit .32BSFC abs/kpa 227 or 1.3bar = 525hp
344 ft.lbs/ tq @ 9000rpm 86 kg/hr limit .32BSFC abs/kpa 228 or 1.3bar = 590hp
344 ft.lbs/ tq @ 10000rpm 95kg/hr limit .32BSFC abs/kpa 227 or 1.3bar = 656hp
344 ft.lbs/ tq @ 10500rpm 100kg/hr limit .32BSFC abs/kpa 227 or 1.3bar = 689hp
315 ft.lbs/ tq @ 11500rpm 100kg/hr limit .32BSFC abs/kpa 208 or 1.1bar = 692hp
290 ft.lbs/ tq @ 12500rpm 100kg/hr limit .32BSFC abs/kpa 191 or 0.9bar = 692hp
269 ft.lbs/ tq @ 13500rpm 100kg/hr limit .32BSFC abs/kpa 177 or 0.8bar = 692hp
250 ft.lbs/ tq @ 14500rpm 100kg/hr limit .32BSFC abs/kpa 165 or 0.6bar = 691hp
242 ft.lbs/ tq @ 15000rpm 100kg/hr limit .32BSFC abs/kpa 159 or 0.6bar = 691hp
Interesting !
comparing 15000 with 10500 I'm thinking frictional bhp would be about 60 more at 15000
are we saying that the turbo (and related pressures) take 60 bhp less at 15000 ? ..... or how much less ?
What I'm saying is the intake boost will have to decrease from 10500k to 15000k based on the fuel rule. Or the VE will drop at the higher rpm and intake boost can stay the same or increase.
surely we have 2 different engines here, a 'slow' 1.1 bar boost engine and a 'fast' 0.6 bar boost engine ?
surely the optimal CR of these 2 would be very different ie hugely dependent on the boost used ?
(the induction and exhaust system design would be rpm-specific also ?)
It would be just one engine with dynamic compression changes control by intake boost pressure, cam profile and turbine design.
(without VVT etc) surely one would choose one or the other design, and run it over the smallest rpm range possible ?
Yes it will have a much smaller rpm range then what I posted. This was just to see the vast changes.
BTW your power measurements (related to your BSFCs measured), was this rolling road or crankshaft ? interesting any way!
This would all be crankshaft HP.
Keep in mind the BSFC and VE are just a guess on my part.
My spreadsheet's inputs are
engine size
rpm
intake pressure
elevation
IAT
injector size
VE
how many cylinders
a/f ratio
bsfc
primary/psi
seconadry/psi
primary emp
secondary emp
% waste-gated
number of turbo's
fuel spec gravity
egt
turbine outlet pressure