Ferrari Power Unit Hardware & Software

[PlatinumZealot]

The fuel flow to engine as used in 2019. Between 3 and 4 low pressure electrically driven fuel pick-up pumps picks-up fuel from tank comartments and supply fuel at low pressure true a one-way valve to the fuel collector-pot. Fuel collector-pot vents air and access fuel supplied back to tank through a one-way pressur/vent regulator. Fuel from pressurised collector pot flows through fuel flow meter to feed intake of high pressure mechanically driven pump (normally driven by an intake camshaft) through a one-way valve incorporated in intake of high pressure pump. The high pressure pump delivers fuel flow to the injectors fundamentally proportional to engine RPM. The fuel cobsumed by the engine is also approximately proportional to RPM at full throttle. But at closed throttle, the engine uses no fuel. To match the fuel supplied to RPM at full throttle, the pump has a variable displacement mechanism actuated by a sophisticated pressure regulating device. The injectors fuel flow is controlled by SECU (standard electronic control unit) The SECU hardware and control software is common to all F1 engines, but the calibrations are free withen range permitted by FIA. All fuel that passes through the fuel flow meter must end-up in combustion chambers. There is no fuel return to the fuel tank and neither fuel 'backflow' through the fuel flow meter. The presurised fuel collector pot eleminates airation from the fuel supplied to the engine.

There is no high pressure pump on earth that can change its displacement so fast as it would require for this application. Without a pressure regulating valve after the high pressure fuel pump the fuel parts after the high pressure pump would explode when you suddenly let go of the throttle at high rpm and there is zero demand for fuel.

However the high pressure fuel pump is matched to the regulations so it cannot supply more fuel than the allowed amount below a certain rpm, above this rpm the excess fuel must be bled off by a fuel pressure regulating valve.

That’s the most stable way of controlling your fuel supply to the injectors. Now you have a constant pressure and flow(regulated) and only need to work with the timing of the injectors to match your demand from the engine.

F1 engineers can surely tweak and maximize this to better fit their demands but the basics will be the same.

So when you don’t measure the fuel flow that is dumped away you need to measure the fuel amount in the tank before and after the race to see if it corresponds to what you measured with the sensor. With a second fuel flow sensor you would have control over all fuel that passed the high pressure pump in every scenario.

So the potential to “cheat” in my opinion is to harvest/collect the fuel that is bled off from the pressure regulating valve and then introduce the fuel into the high pressure fuel pump when you have the demand for more power. Now you have more fuel available for the injectors than the fuel flow sensor can measure. As the engines are very “detuned” when it comes to fuel I believe even a smaller amount of fuel could make a big difference.

A likely scenario could also be that the term pressure regulating valve is just named as a safety valve. In one or another way the maximum pressure must be regulated as the high pressure pump is mechanical and works in relation to the rpm of the engine. The maximum fuel rail pressure is also regulated. On a DI engine you want as high fuel rail pressure as possible, this gives you a better consistency of your spray pattern related to the cylinder pressure.

No need for a regulator if the pump has a means of reducing or cutting its output to achieve the same.

For example you could use a variable speed drive or an internal relief mechanism in the pump.

[PlatinumZealot]

The fuel flow to engine as used in 2019. Between 3 and 4 low pressure electrically driven fuel pick-up pumps picks-up fuel from tank comartments and supply fuel at low pressure true a one-way valve to the fuel collector-pot. Fuel collector-pot vents air and access fuel supplied back to tank through a one-way pressur/vent regulator. Fuel from pressurised collector pot flows through fuel flow meter to feed intake of high pressure mechanically driven pump (normally driven by an intake camshaft) through a one-way valve incorporated in intake of high pressure pump. The high pressure pump delivers fuel flow to the injectors fundamentally proportional to engine RPM. The fuel cobsumed by the engine is also approximately proportional to RPM at full throttle. But at closed throttle, the engine uses no fuel. To match the fuel supplied to RPM at full throttle, the pump has a variable displacement mechanism actuated by a sophisticated pressure regulating device. The injectors fuel flow is controlled by SECU (standard electronic control unit) The SECU hardware and control software is common to all F1 engines, but the calibrations are free withen range permitted by FIA. All fuel that passes through the fuel flow meter must end-up in combustion chambers. There is no fuel return to the fuel tank and neither fuel 'backflow' through the fuel flow meter. The presurised fuel collector pot eleminates airation from the fuel supplied to the engine.

There is no high pressure pump on earth that can change its displacement so fast as it would require for this application. Without a pressure regulating valve after the high pressure fuel pump the fuel parts after the high pressure pump would explode when you suddenly let go of the throttle at high rpm and there is zero demand for fuel.

However the high pressure fuel pump is matched to the regulations so it cannot supply more fuel than the allowed amount below a certain rpm, above this rpm the excess fuel must be bled off by a fuel pressure regulating valve.

That’s the most stable way of controlling your fuel supply to the injectors. Now you have a constant pressure and flow(regulated) and only need to work with the timing of the injectors to match your demand from the engine.

F1 engineers can surely tweak and maximize this to better fit their demands but the basics will be the same.

So when you don’t measure the fuel flow that is dumped away you need to measure the fuel amount in the tank before and after the race to see if it corresponds to what you measured with the sensor. With a second fuel flow sensor you would have control over all fuel that passed the high pressure pump in every scenario.

So the potential to “cheat” in my opinion is to harvest/collect the fuel that is bled off from the pressure regulating valve and then introduce the fuel into the high pressure fuel pump when you have the demand for more power. Now you have more fuel available for the injectors than the fuel flow sensor can measure. As the engines are very “detuned” when it comes to fuel I believe even a smaller amount of fuel could make a big difference.

A likely scenario could also be that the term pressure regulating valve is just named as a safety valve. In one or another way the maximum pressure must be regulated as the high pressure pump is mechanical and works in relation to the rpm of the engine. The maximum fuel rail pressure is also regulated. On a DI engine you want as high fuel rail pressure as possible, this gives you a better consistency of your spray pattern related to the cylinder pressure.

I really don’t know how the fuel flow system in a 2019 F1 car works but the high pressure pump is probably a positive pump type. But that doesn’t automatically mean there needs to be a pressure overflow valve in the line after the hp pump. There are variable volume positive pumps but more easily an electronic torque limiter on the drive would give you much more possibilities and control on desired pressure than a simple pressure valve. Even an internal overflow in the hp pump would be more logical than an external valve with return to the fuel tank.

If all teams would have to use a pressure valve and return line to the fuel tank, the FFM values of the amount of fuel used in the race would always be totally useless.

Furthermore, the FIA confiscated Ferrari’s fuel lines after Brasil and I’m pretty sure they won’t allow fuel return from the pressure valve buffered and on a later moment supplied to the hp pump after the FFM.
In that design it’s very simple to exceed the maximum flow of 100kg/h without noticed by the FFM. In other words, the FFM values for the flow would be useless too.

Hmm.. I don't beleive the flow meter is located after the high pressure pumps. There seems to be two camshaft driven pumps total, one on each bank of the engine if i remember correctly... And likely that the lines go directly to the injector rails..?

[saviour stivala]

In 2014 the first year of the hybrid power unit formula I read a technical article (not on here) that stated that Renault was the only one of the three engines present back than to have been using two high pressure mechanical fuel pumps with each being driven by an inlet camshaft from each bank at one half engine RPM.
Up to the 18000 RPM 2.4l V8 (2013) the high pressure (100 bar) mechanical fuel pump was situated right inside the fuel tank and was normally driven by the engine water cooling pump shaft. In the case of FERRARI, it, the high pressure fuel pump and its drive from the engine water pump were driven at 34% of engine speed of which was calculated to be driven at the most efficient speed as were the rest of the auxiliary drives at their respective driven speed. Pressure oil pump=32.5%. de-aerator, alternator, hydraulic pump=71.5%. scavange pumps=35.5%.

Il-Milied Hieni lil kullhad.

[Polite]

@Aral, Could you please direct me to the source too? I can not find this anywhere. Thank you .

Fia writes official announcements only in the event of irregularities!
While there were a lot of unoffcial statemets by members of the FOM/FIA about regularity of the Ferrari pus after the checks (i can remember of Brawn after the USA GP..)..

Where did you come up with the idea that the FIA only creates new technical directives when they find irregularities in a competitors car?

No! i said Fia writes something only in case of irregularities after a check.

Directives are a different topic.



About the topic: new design of the PU relative to the top header, upgrade for the combustion chamber!

[saviour stivala]

"New design, upgrade for the combustion chamber" unfortunately such engine internal upgrades we followers have no chance of ever learning about. so await some bright-spark to come out speculating as to what is being used the likes of what happened before, first with HCCI and than with Mahle jet ignition.

[Wouter]

About the topic: new design of the PU relative to the top header, upgrade for the combustion chamber!

Do you have a reliable source @Polite? Thanks in advance.

[MtthsMlw]

About the topic: new design of the PU relative to the top header, upgrade for the combustion chamber!

Do you have a reliable source @Polite? Thanks in advance.

"We have changed, by quite a lot, our power unit, in terms of architecture, the cylinder," said team principal Mattia Binotto.

"It's quite a big review just to show that here again, there is much that can be done. The change we are looking for next year is quite significant changes on the engine itself."

https://www.motorsport.com/f1/news/ferr ... 0/4612841/

[nzjrs]

The fuel flow to engine as used in 2019. Between 3 and 4 low pressure electrically driven fuel pick-up pumps picks-up fuel from tank comartments and supply fuel at low pressure true a one-way valve to the fuel collector-pot. Fuel collector-pot vents air and access fuel supplied back to tank through a one-way pressur/vent regulator. Fuel from pressurised collector pot flows through fuel flow meter to feed intake of high pressure mechanically driven pump (normally driven by an intake camshaft) through a one-way valve incorporated in intake of high pressure pump. The high pressure pump delivers fuel flow to the injectors fundamentally proportional to engine RPM. The fuel cobsumed by the engine is also approximately proportional to RPM at full throttle. But at closed throttle, the engine uses no fuel. To match the fuel supplied to RPM at full throttle, the pump has a variable displacement mechanism actuated by a sophisticated pressure regulating device. The injectors fuel flow is controlled by SECU (standard electronic control unit) The SECU hardware and control software is common to all F1 engines, but the calibrations are free withen range permitted by FIA. All fuel that passes through the fuel flow meter must end-up in combustion chambers. There is no fuel return to the fuel tank and neither fuel 'backflow' through the fuel flow meter. The presurised fuel collector pot eleminates airation from the fuel supplied to the engine.

I think you've lifted most of these quotes from an article in Racecar engineering (https://www.racecar-engineering.com/art ... l-systems/)where they are describing the pre-2014 Formula 1 fuel pump. With the hybrid nature of the current F1 PU I can't see some of your statements working correctly in 2019.

and

In 2014 the first year of the hybrid power unit formula I read a technical article (not on here) that stated that Renault was the only one of the three engines present back than to have been using two high pressure mechanical fuel pumps with each being driven by an inlet camshaft from each bank at one half engine RPM.
Up to the 18000 RPM 2.4l V8 (2013) the high pressure (100 bar) mechanical fuel pump was situated right inside the fuel tank and was normally driven by the engine water cooling pump shaft. In the case of FERRARI, it, the high pressure fuel pump and its drive from the engine water pump were driven at 34% of engine speed of which was calculated to be driven at the most efficient speed as were the rest of the auxiliary drives at their respective driven speed. Pressure oil pump=32.5%. de-aerator, alternator, hydraulic pump=71.5%. scavange pumps=35.5%.

Il-Milied Hieni lil kullhad.

In addition to what subcritical71 listed above, as far as I can tell, the paragraph above comes partly from an article the Renault v8 fuel system, first posted here http://media.renaultsport.com/Renault-S ... html?r=331 and then picked up by motosport.com https://www.motorsport.com/f1/news/rena ... ra/434357/ and possibly this article from Scarbs https://scarbsf1.wordpress.com/2012/06/ ... el-system/. Additionally, the statement above "In the case of FERRARI.." might have came from this autosport forum post (sadly missing now the images) https://forums.autosport.com/topic/6897 ... ?p=1667558.

edit: original link

[hape]

I really don’t know how the fuel flow system in a 2019 F1 car works but the high pressure pump is probably a positive pump type. But that doesn’t automatically mean there needs to be a pressure overflow valve in the line after the hp pump. There are variable volume positive pumps but more easily an electronic torque limiter on the drive would give you much more possibilities and control on desired pressure than a simple pressure valve. Even an internal overflow in the hp pump would be more logical than an external valve with return to the fuel tank.

If all teams would have to use a pressure valve and return line to the fuel tank, the FFM values of the amount of fuel used in the race would always be totally useless.

Furthermore, the FIA confiscated Ferrari’s fuel lines after Brasil and I’m pretty sure they won’t allow fuel return from the pressure valve buffered and on a later moment supplied to the hp pump after the FFM.
In that design it’s very simple to exceed the maximum flow of 100kg/h without noticed by the FFM. In other words, the FFM values for the flow would be useless too.

Hmm.. I don't beleive the flow meter is located after the high pressure pumps. There seems to be two camshaft driven pumps total, one on each bank of the engine if i remember correctly... And likely that the lines go directly to the injector rails..?

Sorry for being a little unclear in my wording, I'll try to explain

Furthermore, the FIA confiscated Ferrari’s fuel lines after Brasil and I’m pretty sure they won’t allow fuel return from the pressure valve buffered and on a later moment supplied to the hp pump after the FFM."

What I meant was "buffered fuel returned after the FFM but still on the suction (low pressure) side of the hd pump". The FFM is indeed comes first, then the hd pump.
But this "returned buffered fuel" makes no sense.

I guess the system works with multiple pick up pumps in the fuel tank, on the pressure side they connect to a single line before they pass the one and only FFM. From the FFM the line goes to the intake of the HP pump.
From there I don't know how things proceed but according to saviour stivala the F1 engine makers use a variable displacement pump which to me is quite well possible.
From the pressure side of the pump the lines go straight to the fuel injector rails.

Using a pressure relief valve after the hd pump (according to PederJonsson) to prevent hd pump damage (spilling the overflow back into the fuel tank) is not necessary.
In fact it is unwanted. I tried to explain above by doing so you ruin the max fuel flow measurement and the measurement for kg's burned fuel in the race. So I would be surprised to see a pressure valve after the HD pump.

[PederJonsson]

I really don’t know how the fuel flow system in a 2019 F1 car works but the high pressure pump is probably a positive pump type. But that doesn’t automatically mean there needs to be a pressure overflow valve in the line after the hp pump. There are variable volume positive pumps but more easily an electronic torque limiter on the drive would give you much more possibilities and control on desired pressure than a simple pressure valve. Even an internal overflow in the hp pump would be more logical than an external valve with return to the fuel tank.

If all teams would have to use a pressure valve and return line to the fuel tank, the FFM values of the amount of fuel used in the race would always be totally useless.

Furthermore, the FIA confiscated Ferrari’s fuel lines after Brasil and I’m pretty sure they won’t allow fuel return from the pressure valve buffered and on a later moment supplied to the hp pump after the FFM.
In that design it’s very simple to exceed the maximum flow of 100kg/h without noticed by the FFM. In other words, the FFM values for the flow would be useless too.

Hmm.. I don't beleive the flow meter is located after the high pressure pumps. There seems to be two camshaft driven pumps total, one on each bank of the engine if i remember correctly... And likely that the lines go directly to the injector rails..?

Sorry for being a little unclear in my wording, I'll try to explain

Furthermore, the FIA confiscated Ferrari’s fuel lines after Brasil and I’m pretty sure they won’t allow fuel return from the pressure valve buffered and on a later moment supplied to the hp pump after the FFM."

What I meant was "buffered fuel returned after the FFM but still on the suction (low pressure) side of the hd pump". The FFM is indeed comes first, then the hd pump.
But this "returned buffered fuel" makes no sense.

I guess the system works with multiple pick up pumps in the fuel tank, on the pressure side they connect to a single line before they pass the one and only FFM. From the FFM the line goes to the intake of the HP pump.
From there I don't know how things proceed but according to saviour stivala the F1 engine makers use a variable displacement pump which to me is quite well possible.
From the pressure side of the pump the lines go straight to the fuel injector rails.

Using a pressure relief valve after the hd pump (according to PederJonsson) to prevent hd pump damage (spilling the overflow back into the fuel tank) is not necessary.
In fact it is unwanted. I tried to explain above by doing so you ruin the max fuel flow measurement and the measurement for kg's burned fuel in the race. So I would be surprised to see a pressure valve after the HD pump.

The mechanical hp fuel pump is a piston pump, the piston travels up and down, that means it gets fuel into its chamber during one direction, the other direction it’s pressurizing the fuel out to the fuel line.
If the fuel pump only would deliver the maximum pressure described in the rules you would have fluctuations of the pressure in the fuel lines when the injectors open.

So to overcome this the pressure delivered out from the hp fuel pump is higher than permitted in the rules and then regulated down trough a relief valve so the fuel line pressure is according to the rules. This relief valve could also be in the housing of the hp fuel pump.

As the pump is mechanical and follows the engine speed and should deliver fuel all over the RPM range but limit its capacity after 10500rpm.

By controlling the pressure you also control the flow as pressure is just a measurement of the resistance in a circuit.

The system would be most efficient the closer the hp fuel pump can get to the pressure regulation but it will still need some buffer to not fluctuate.

I also can’t see any other way to control the maximum pressure, I say so from my experience with tuning DI engines(Audi/VW, BMW and Mercedes). Of course the engines I work with is not as refined as those in F1. However the fuel systems I work with could do all that is done in F1 except when it comes to the injectors as the combustion process is so different.

If you ever seen an injector being tested you can see how different the spray pattern becomes when you change the pressure. Also the high cylinder pressure even at low loads (due to the high CR 18:1) makes it important to have good control over your spray pattern. This is one of the biggest reason I’m convinced that a constant pressure is required.

So with above in mind and trying to see where one could cheat and I saw the relief valve as a potential part.

I could of course be wrong and it wouldn’t be the first time.

[saviour stivala]

The mechanical hogh pressure fuel pump does not have to ‘suck’ fuel at its inlet port as its inlet port is supplied pressurised fuel from the pressurised collector pot. This constant flow pressurised fuel supply from the collector pot prevents cavitaion occuring at maximum flow rate from the high prssure pump. The pressurised collector pot is not effected by fuel surg and slosh due to g-forces. The high pressure pump matches fuel supply to engine RPM. The pump has a variable displacement mecanism actuated by a sophisticated pressure regulating device. This 500 bar pump does not require a fuel return to fuel tank because it have an intergrated flow control valve as well as an internal pressure relief valve.

[gruntguru]

Even if the high pressure pump did require a return line, that could direct fuel back to the inlet side of the high pressure pump, which of course is after the flow meter and would have no effect on the flow measurement. If all lines in this supply, return loop were sufficiently rigid, the volume in the loop would remain constant (subject to the note in the paragraph below) and flow through the flowmeter would be equal to flow through the injectors.

There needs to be a small accumulation component in the lines between the high pressure pump and the injectors. This is because the injector flow is intermittent and the pump flow has a much longer time constant. The time constant of this accumulation would be very short and has the effect of averaging the flow through the sensor. As TC has previously pointed out, while an injector is open, (at max power) the flow is much higher than 100 kg/hr and while all injectors are closed, the flow is zero so some averaging is required.

[saviour stivala]

According to rule/regulations the flow through the flow meter have to be equal to the flow through the injectors (all fuel that passes through the fuel flow meter must end-up in the comnbastion chambers). If the flow through the injectors (kg/h) is more than stipulated the car time will be disqualified.
“there need be a small accumulation” The small accumulation is common to all. Re high pressure pump pressure regulating/pressure relieve-valve/s that regulates the pressure of the pump. (The pump variable displacement mechanism (flow volume) (is actuated by a sophisticated pressure regulating valve that also regulates the pressure. Says it all).
Fuel accumulation (storing) in so called ballooning/expanding fuel lines has been talked about a lot. Poeple on this here discution should please keep in mind that ‘most’ if not ‘all’ of the fuel system parts including the fuel itself would according to rules/regulations have to be approved by the FIA.

[hollus]

Ok. Some sort of averaging time will have to be part of the measurement. Whether it is implicit or explicit, in a technical directive or built in into the sensor I don’t know. But in the ultimate limit when a molecule passed through, the flow was infinite and the rest of the time zero. The averaging time might be a microsecond or several seconds, and until we know that, we can only speculate and no one will get to “be right”.
Similarly with ballooning lines. Infinitely stiff materials do not exist, everything yields to a point. Similarly with pressure, the incompressible fuel that does not change density with changing pressure snd temperature is only a mental idealization.

I think that the discussion would benefit a lot from not going to the extremes of ideal constructions, ideal materials and perfect sensors. (Posted as a user).

Of course, if FIA would just make those directives public...

[Tommy Cookers]

According to rule/regulations the flow through the flow meter have to be equal to the flow through the injectors (all fuel that passes through the fuel flow meter must end-up in the comnbastion chambers). If the flow through the injectors (kg/h) is more than stipulated the car time will be disqualified. ....

isn't this incorrect ?
(yet again)
the fuel rate through the injectors isn't stipulated anywhere
only the fuel rate through the meter is stipulated
we cannot assume that because every nanogram of fuel passed through the engine has passed through the meter ...
the fuel rates at all points will always be identical

there is a mass of fuel downstream of the injection pump
and another mass of fuel upstream of that pump but downstream of the meter
(how) won't (both) these masses vary through time ?
(even when the fuel rate is continuously at the limit)