F1technical.net

I was thinking how many HP each engine has in qualifying. I'm guessing that Mercedes PU can generate around 790HP (at max ers boost). Am I right? And how many HP other engines can have? Also, how high is their peak rpm and estimated compression ratio?

So you wanna start a discussion based on a guess?

There are many threads on this forum that go into detail about this, based on calculations rather than guessing.

Based on my own calculations, I would say your guess is a little on the low side, but that is the subject of these other threads...

The math is quite simple really, let's start with the basic assumptions:

Fuel energy: 46MJ/kg
Maximum Fuel Flow: 100kg/h or 0.0278kg/s (As per the Tech Regs)

Estimated ICE efficiency:
Conservative: 38%
Likely: 40-43%

MGU-K Output
Sustainable MGU-K Power (continuous): 70kW (Brayton Cycle power from MGU-H)
Full Battery Power (as per Tech Regs): 120kW

Increased ICE Power from bypassing Turbine, and powering compressor from Battery via MGU-H: 15kW (Quali mode)

At 38% efficiency PU Power output is estimated as ICE + MGU-K Power:

ICE Power = Fuel Energy x Fuel Flow Rate x Efficiency = 46 x 0.0278 x 38% = 486kW (~650hp)

Total PU output in various modes (for 38% ICE Efficiency):
Sustainable Mode (+70kW from MGU-K): 556kW (or ~740hp)
Full Battery Mode (+120kW from MGU-K): 606kW (or ~810hp)
Quali Mode (+120kW from MGU-K and extra 10kW from ICE): 621kW (or ~825hp)


If we consider an ICE efficiency between 40-43% (which has been suggested), we get:

ICE Power: 510-550kW (680-730hp)

Total PU output in various modes:
Sustainable Mode (+70kW from MGU-K): 580-620kW (or 775-826hp)
Full Battery Mode (+120kW from MGU-K): 630-670kW (or 840-890hp)
Quali Mode (+120kW from MGU-K and extra 10kW from ICE): 645-685kW (or 860-915hp)

My math is rough, but it gives a crude approximation. Peak power will be between 10,500 and 11,000RPM, as the fuel flow rate increases to 10,500 and is then fixed at 100kg/h.

I will wait for GruntGuru to chime in and give you a more formal education...

In the mean time, try this: http://www.f1technical.net/forum/viewto ... f=4&t=9259

Great post Wayne!
thank you!

Over 900 hp is insane with these power units! I would not be surprised if the numbers are already going to 950 hp, since Mercedes stated that they would be close to 1000 hp in about a year or so. Maybe they are already generating so much electric energy from the MGU-H that the 120 kW of the MGU-K is limiting the combined power output from the power unit. I would say, lets increase the MGU-K power to 150 kW or more and go for the 1000 hp! (with only 1600cc )

damn reading max 915 horspower is insane

we know they are over 40% efficient from a press conference where Mercedes played it cool and Renault guys basically said they´re over 40% in efficiency.

If you read posts here from just over a year ago, many were saying 850hp was not achievable. That's F1 for you!

@ Wayne
please, who is saying that the ICE can be 40-43% efficient ?
(aren't 40-43% claims are for 'sustainable' PU efficiency ??)

70 kW Brayton cycle power ?

ok, race-sustainable power could include whatever (default) KE recovery power is available whenever driver accelerator demand is 100%

Tommy Cookers wrote:@ Wayne
please, who is saying that the ICE can be 40-43% efficient ?
(fwiw - afaik 40-43% claims are for the PU efficiency)

70 kW Brayton cycle power ?

ok, sustainable power could include whatever KE recovery power is always available whenever driver accelerator demand is 100%)

http://www.theengineer.co.uk/news/mercedes-f1-power-unit-honoured-as-outstanding-example-of-british-engineering/1019429.article wrote:With a claimed thermal efficiency of more than 40 per cent the Mercedes is said to be the most thermally efficient gasoline powertrain ever produced and has been a key factor in helping Mercedes AMG Petronas secure the 2014 FIA Formula One Constructors’ Championship.

From a quick search. I am sure there was more announced at the time the PU received the Dewar trophy.

thermally efficient ICE or PU ? - that's the question
it appears to be the PU
so it has already added at least the exhaust recovered power to the crankshaft power
and maybe already added some power from recovered KE (which activity is commendable but a misrepresentation of the BTE)

so these powers should not be added again eg by Wayne
(if that is what he has done - apologies if I have misunderstood his post)

the Dewar trophy was voted by a bunch of technically unqualified journos
previous winners include Vanwall and Coventry Climax - for what outstanding technical advancements exactly ?

"... and Coventry Climax - for what outstanding technical advancements exactly ?"

Powering two teams to Four world championships?

...

arguably among the most thermally efficient gasoline powertrains ever produced, with a claimed thermal efficiency of greater than 40%
http://www.greencarcongress.com/2014/10 ... dewar.html

650hp max. that's where i put it for the ICE.

I think the claim is >40% BTE for the power unit at some limited operating condition. I can see this being possible for the PU itself, but not for the complete drivetrain.

F1 engine designs are highly optimized for their specific application. So they can be made very efficient. A production auto engine on the other hand, must be designed within the more difficult constraints of cost, service life, emissions, driveability, etc.

I think some sources have been more explicit with terms like "self sustaining mode" which indicates (to me at least) a mode where the ICE can be run continuously without any inputs other than the 100kg/hr of fuel. The term "BTE" is only applicable to heat engines since it describes the rate of conversion of heat energy to mechanical work.

Add to this, the knowledge that 37% is available from the showroom floor (Prius with no compounding - 40+% coming soon) and it becomes obvious (to me at least) that the 40+% BTE claim is the ICE (piston engine plus turbine surplus) at continuous full power.