Ferrari Power Unit Hardware & Software

[henry]

Maybe thee secret button holds the pop-off valve open?

[saviour stivala]

Interesting remarks. Especially at the 3:15 mark...'MGU-H is not allowed to produce boost, as such, so it cannot be used as an electric turbocharger'. Did I miss something?

i also thought the MGU H can be used to spin up the Turbo at low speed?
or am i getting it wrong here? please correct me

At the traxk

At the track i even heard the turbo’s spin up, when revving the engine for a (simulation) start. Sounded like the turbo/mgu was spinning at max rpm, while the crankshaft was kept at 7000-8000 before they relause the clutch peddle.

Technically speaking the introduction of the MGU-H eliminated the need to use waste-gates. Waste-gates found their way back into the turbo system design specifically because of the use of the turbo operated in electric supercharging mode.

[saviour stivala]

Maybe thee secret button holds the pop-off valve open?

pressing the 'secret button' to hold a 'turbo pop-up valve' open will drop the turbo boost.
anyhow they do not use a pop-up valve, they use a diverter valve which diverts the boost (over-boost when throttle is lifted) back into the non-pressure side of the intake (re-circulate).

[henry]

Maybe thee secret button holds the pop-off valve open?

pressing the 'secret button' to hold a 'turbo pop-up valve' open will drop the turbo boost.
anyhow they do not use a pop-up valve, they use a diverter valve which diverts the boost (over-boost when throttle is lifted) back into the non-pressure side of the intake (re-circulate).

Call it what you will you seem to have got the start of an understanding of what Iwas suggesting.

Imagine the compressor assembly is running at a speed that would produce the boost required for launch, the “diverter” is held open with reduced boost until start, when the valve is closed, the pressure rises and off we go. I make the assumption that the pressure rise will be quicker than speeding up the turbo.

But maybe that’s not necessary, it all depends if the ICE at no load is happy to maintain launch revs with high boost.

[subcritical71]

Call it what you will you seem to have got the start of an understanding of what Iwas suggesting.

Imagine the compressor assembly is running at a speed that would produce the boost required for launch, the “diverter” is held open with reduced boost until start, when the valve is closed, the pressure rises and off we go. I make the assumption that the pressure rise will be quicker than speeding up the turbo.

But maybe that’s not necessary, it all depends if the ICE at no load is happy to maintain launch revs with high boost.

I think I see where you're going with this. And it also doesn't need to be analog, does it (open or closed)? Could it be throttled to a predetermined sweet spot. One that allows the turbo to spool up sufficiently using exhaust gases, but since the compressor isn't at a full load the turbine needs less exhaust gas to maintain speed, corresponding to launch RPM. With this strategy you're not wasting precious energy from the battery and can instead use that later in the lap.

[NL_Fer]

i also thought the MGU H can be used to spin up the Turbo at low speed?
or am i getting it wrong here? please correct me

At the traxk

At the track i even heard the turbo’s spin up, when revving the engine for a (simulation) start. Sounded like the turbo/mgu was spinning at max rpm, while the crankshaft was kept at 7000-8000 before they relause the clutch peddle.

Technically speaking the introduction of the MGU-H eliminated the need to use waste-gates. Waste-gates found their way back into the turbo system design specifically because of the use of the turbo operated in electric supercharging mode.

BS.

They needed a wastegate to control certain transient pressure spikes, during fast throttle movements. Renault in ‘15 tried without and used a heatsink instead, did not work. The result, a very clumsy external wastegate was added after a few races. This was visable one time in Monza, when a Torro Rosso engine cover just blew off in practice.

[henry]

Call it what you will you seem to have got the start of an understanding of what Iwas suggesting.

Imagine the compressor assembly is running at a speed that would produce the boost required for launch, the “diverter” is held open with reduced boost until start, when the valve is closed, the pressure rises and off we go. I make the assumption that the pressure rise will be quicker than speeding up the turbo.

But maybe that’s not necessary, it all depends if the ICE at no load is happy to maintain launch revs with high boost.

I think I see where you're going with this. And it also doesn't need to be analog, does it (open or closed)? Could it be throttled to a predetermined sweet spot. One that allows the turbo to spool up sufficiently using exhaust gases, but since the compressor isn't at a full load the turbine needs less exhaust gas to maintain speed, corresponding to launch RPM. With this strategy you're not wasting precious energy from the battery and can instead use that later in the lap.

Sort of.

My thinking was (coloured by red wine) that the accelerator is a torque demand and when stationary, clutch disengaged, the driver would only need to demand a very small amount of torque to get the engine to launch revs. So at lights out they would need to coordinate clutch and accelerator to increase torque demand to that required for a perfect getaway. If the driver can open the pop-off they could make a higher torque demand and the ECU would command a boost level etc, and hence torque, which would be truncated until the pop-off we’re closed.

When I put it like that I realise it might also be feasible to use the MGU-K to absorb the engine torque until the button is released. The sequence would be:

First light on , press button, press accelerator until launch revs reached. The ECU. Would demand launch torque but that would be curtailed by the MGU-K and reduced boost to a value that holds the PU at launch revs

Lights off, release button, switch off MGU-K, close pop-off, and now you have a good approximation to optimal launch torque with very little delay.

This may run foul of the restriction on using the MGU-K “during a race start”. Question is does a race start begin when the race start procedure starts or when the lights go off or when the car starts to move?

[gruntguru]

All energy (including electrical) available to an F1 car comes from the 100Kg fuel it carries. Therefore, if expected energy use doesn't fit after fitting weights and drag coefficients into their equations, then they might conclude that the 100Kg fuel limit is being breached somehow and speculate by what mechanism the extra energy is coming in.

It is interesting to consider an overview of the energy storage and flows in an F1 car.
- The car starts the race with about 4.4 GJ of chemical energy on board.
- The chemical energy can be consumed at a maximum rate of 44 MJ/minute. (1200kW)
- In "self sustaining" mode the piston engine converts about 45% of this - 540kW directly to mechanical work at the crankshaft.
- In "self sustaining" mode the turbine converts about 5% of this - 60kW to mechanical work to the MGUH (after allowing for direct work to drive the compressor.)
- In "self sustaining" mode the remaining 50% - 600kW is lost as heat through the heat exchangers and exhaust.
- So about 50% of the fuel load is converted to do useful work. (Less than this because the PU is often operated at other than peak efficiency eg part load or electric supercharger mode)
- Of the energy doing useful work, some is used more than once. This is the braking energy captured by the MGUH - about 2MJ/lap depending on the track. Over 70 laps this is 140MJ - 3% of the total fuel energy or 6% of the useful work - recycled.

This is pretty informative. Its a wonderful post, thanks.

I don't agree with is the last point (energy being used more than once) - instead a portion of energy that would have been lost as heat or drop in KE is saved, but that might be what you meant.

I'm particularly interested in drive train losses in an F1 car, would you have any figures for this? Especially gearbox and differential.

Probably less than 5% total loss in gearbox and final drive.

Re - energy being recycled. Just saying that the braking energy harvested was originally "work" used to accelerate the car (ie converted to KE) then converted to electrical energy by the K, stored in the ES, then used again to accelerate the car via the K (or perhaps by the H to drive the compressor). So the regen' energy was used as "work" twice.

All other KE is lost to the environment as heat via the brake discs or aerodynamic drag losses (eventually becoming heat in the atmosphere).

[gruntguru]

Have you guys seen this video?
https://www.youtube.com/watch?v=8Q1gGmU40zA

Yes, it was posted a page or two ago (viewtopic.php?f=4&t=21958&start=2895#p796171). Thanks again for it though. Which leads me back to what was said ~3:50.

I think the rules are being misinterpreted here. For one thing it is not possible to "spool" the compressor without creating boost. Try reading it this way:

5.1.6 Pressure charging may only be effected by the use of a sole single stage compressor and it may only be linked to (driven by) a sole single stage exhaust turbine and an electrical motor generator (MGU-H)

I'm not sure, but not convinced 100% either way either. The spool up part for instance, agreed you can't spool up without producing boost, however they may be able to spool until just as boost is increased, from the H, tough one to do and police in my eyes. You can have something connected and yet not able to drive it directly. There is a provision for a clutch also. The more I read it the more inclined I am to agree with Scarbs interpretation.

Has there ever been a team which has stated they use electric turbo/supercharging? I know, it's like asking if they have verified that they use spark plugs, but if they have said it directly then it could be put to bed.

There have been many videos posted here where the use of electric supercharger mode is obvious. You see a car accelerating hard then when it reaches the speed where it is no longer traction limited, you hear the wastegate open (much louder exhaust) and the car continues at maximum acceleration. If this was a case of simply opening the wastegate enough to control boost there would be only a very small power gain compared to controlling boost with the H and tolerating a small increase in exhaust back pressure while drawing much less from the ES.

[MtthsMlw]

Just for the record: the Ferrari is still making the screaming noise while accelerating.

[GrandAxe]

It is interesting to consider an overview of the energy storage and flows in an F1 car.
- The car starts the race with about 4.4 GJ of chemical energy on board.
- The chemical energy can be consumed at a maximum rate of 44 MJ/minute. (1200kW)
- In "self sustaining" mode the piston engine converts about 45% of this - 540kW directly to mechanical work at the crankshaft.
- In "self sustaining" mode the turbine converts about 5% of this - 60kW to mechanical work to the MGUH (after allowing for direct work to drive the compressor.)
- In "self sustaining" mode the remaining 50% - 600kW is lost as heat through the heat exchangers and exhaust.
- So about 50% of the fuel load is converted to do useful work. (Less than this because the PU is often operated at other than peak efficiency eg part load or electric supercharger mode)
- Of the energy doing useful work, some is used more than once. This is the braking energy captured by the MGUH - about 2MJ/lap depending on the track. Over 70 laps this is 140MJ - 3% of the total fuel energy or 6% of the useful work - recycled.

This is pretty informative. Its a wonderful post, thanks.

I don't agree with is the last point (energy being used more than once) - instead a portion of energy that would have been lost as heat or drop in KE is saved, but that might be what you meant.

I'm particularly interested in drive train losses in an F1 car, would you have any figures for this? Especially gearbox and differential.

Probably less than 5% total loss in gearbox and final drive.

Re - energy being recycled. Just saying that the braking energy harvested was originally "work" used to accelerate the car (ie converted to KE) then converted to electrical energy by the K, stored in the ES, then used again to accelerate the car via the K (or perhaps by the H to drive the compressor). So the regen' energy was used as "work" twice.

All other KE is lost to the environment as heat via the brake discs or aerodynamic drag losses (eventually becoming heat in the atmosphere).

Thanks.

[hurril]

Just for the record: the Ferrari is still making the screaming noise while accelerating.

Plus it sounds almost exactly like the Renault engines started doing in, what, 2016?

[saviour stivala]

Renault was the last of the original first three to start using electric supercharging mode, not because they didn't had it designed-in, all four engines were born with that design mode, but because of reliability problems.

[hurril]

Renault was the last of the original first three to start using electric supercharging mode, not because they didn't had it designed-in, all four engines were born with that design mode, but because of reliability problems.

I'm sure they were but they were the first ones, in my mind, to sport such a distinctive sound. It's not as noticeable on the mercs and I'm not sure I've even heard it from a Honda.

My comment is more directed at the hullabaloo surrounding whatever is causing that noise from the Ferraris. To me it's very clearly a case of open waste gate(s), that's all.

[saviour stivala]

Renault was the last of the original first three to start using electric supercharging mode, not because they didn't had it designed-in, all four engines were born with that design mode, but because of reliability problems.

I'm sure they were but they were the first ones, in my mind, to sport such a distinctive sound. It's not as noticeable on the mercs and I'm not sure I've even heard it from a Honda.

My comment is more directed at the hullabaloo surrounding whatever is causing that noise from the Ferraris. To me it's very clearly a case of open waste gate(s), that's all.

Was the sound you talking about when they were using just one single waste-gate/s tailpipe?.
No doubt here neither about open waste-gates sound.