Ferrari Power Unit Hardware & Software

[Polite]

An ICE on five cylinders out of six will have seventeen percent less power.

Have u calculated the more friction also? On news papers (motorsport.com or motorionline.it) they talked about 25% less power.
is there a way to calculate the more use of gasoline?
tnk for your math!

[Tommy Cookers]

I'm guessing that it is possible to increase the fuel flow to the remaining cylinders to compensate a bit for the missing cylinder. LEC was being asked to lift and coast so we have to assume that if Ferrari's explanation is correct a lot more fuel per cylinder was being used. How much above 5/6 power would this allow Ferrari to go?

good idea ... but ...
this would need the capability to feed 5 injectors at a rate that would be illegal (over 100 kg/hr total) if fed to 6 injectors
how (and where) would this capability exist in-car ?
or does it exist because for qualification they (excuse my misfiring memory) run fuel rates over 100 kg/hr ?

[NL_Fer]

100kg/hr is limited in the supply line to the fuel rails. If the injectors are capable, they could increase fuel on the remaining 5 cilinders. But it would be less efficient.

[Big Tea]

Two things. First, I assume any 'calculation of lost power' would not be possible to do unless we knew the injector was total 100% dead. some fuel entering at almost any time and pattern would give some power?

As Total fuel flow is controlled, would they be able to make up some space in the operating units by (if they have one) using a mode that would not normally be considered for any race period due to high flow/consumption to get some extra from the other 5?

[subcritical71]

Two things. First, I assume any 'calculation of lost power' would not be possible to do unless we knew the injector was total 100% dead. some fuel entering at almost any time and pattern would give some power?

I was thinking the same. I’ve attempted to drive a V6 engine which was down a single spark plug and it would barely accelerate and the engine was so unbalanced it felt like it would shake itself out of the engine bay. The loss of power will depend on how much of the original flow the injector was able to maintain in its degraded state. From onboard videos the engine didn’t sound all that bad.

[saviour stivala]

To be able to talk (calculate) the power contribution of just one cylinder of the total number of cylinders of an engine, the maximum power output of the engine (all cylinders combined) will have to be known. Whatever the maximum power output might of all cylinders combined might be, the power contribution of one cylinder of an engine in percentage terms depends on the number of cylinders in said engine.
I said that one cylinder of the FERRARI engine out of order (miscombustion) amounts to 17% less power, actually it amounts to 16.666%. which in my personal calculations can amount to as much as 140bhp. and a note here, we are here talking ICE power output contribution to the whole power unit package.
Re-fuel consumption with a v6 engine running on only 5 cylinders. The maximum 100kg/h fuel flow rate @10500rpm mandated by the rules, can as well flow through just one injector as far as the rules are concerned, why?, because the fuel flow is measured by the FIA mandated fuel flow sensor before fuel gets to the engine. It is of no concern to the FIA what the injectors fuel flow capabilities are.

[Tommy Cookers]

fuelling 6 cylinders worth of fuel through 5 cylinders won't recover all the 'missing' power

the 5 cylinders new '6 cylinder' fuel heat is diluted by '5 cylinder' air ie 16.67% less than design air
so 5 cylinder temperatures will tend to increase - but cooling will be increased in response
the heat necessarily removed to cool each '5' cylinder to design temperature will be more than 16.67% greater
ie the total heat necessarily taken will be more than design
so the total heat available for conversion to work will be less ie power will be less than design
if this total heat can't be removed knock protection will automatically retard the ignition ie power will be less than design

[Gibbs]

I don't think a solution to this failure is as simple as redirecting 6 cylinders worth of fuel to 5 cylinders. Already under a dead cylinder there is an imbalance in torque which will cause mechanical and thermal stresses and imbalances in the engines in parts such as the crankshaft, bearings, bolts and cylinder head. The proposal now is to run the engine under a very demanding configuration, as mentioned by Tommy, whilst it is inherently weaker and more susceptible to failure.

Also take into consideration that this would have to be a pre-configured software map for a very specific failure, and correct me if I'm wrong but the technical challenges this involves most likely outweigh the money and time spent developing such a configuration.

[ringo]

We dont have to go into the nitty gritty of fuel consumption to compensate for power loss by one cylinder.
If you car doesn't have have energy recovery you will have to do more fuel saving than was planned.
Ferrari fuels the car with the assumption that the ERS will be working for all of the race. Once you don't have your ERS of course Leclerc will have to save fuel.
In fact it is probably wise not to increase fuel rate if there is a misfire as this may just exacerbate vibrations, and hot spots, and possibly wear to those 5 cylinders that are compensating for the lost one.

Anyhow i am glad that it was a control unit for the injection system, and not the injector itself or any sealed engine hardware that would warrant a change in ICE.

[Big Tea]

I don't think a solution to this failure is as simple as redirecting 6 cylinders worth of fuel to 5 cylinders. Already under a dead cylinder there is an imbalance in torque which will cause mechanical and thermal stresses and imbalances in the engines in parts such as the crankshaft, bearings, bolts and cylinder head. The proposal now is to run the engine under a very demanding configuration, as mentioned by Tommy, whilst it is inherently weaker and more susceptible to failure.

Also take into consideration that this would have to be a pre-configured software map for a very specific failure, and correct me if I'm wrong but the technical challenges this involves most likely outweigh the money and time spent developing such a configuration.

I understand that, and did not mean a specific map for 5 cyl, but as (if?) one cyl was not using any (as much?) as was budgeted, switching to qualli mode or similar would still leave enough to finish the race, as it would be using 5/6 of what it should with X laps remaining.

[zibby43]

Anyhow i am glad that it was a control unit for the injection system, and not the injector itself or any sealed engine hardware that would warrant a change in ICE.

Is it normal for something like a short circuit to occur in the middle of the race, as opposed to on startup?

[ringo]

I don't know to be honest, but i can imagine with prolonged exposure to heat, maybe a poorly made insulator may have loosened. Or possibly build up of moisture in a connector because of manufacturing fault?
Usually the connectors are supposed to be weather proof. It's possible a gland may have been breached and moisture got in.

[Zynerji]

I don't know to be honest, but i can imagine with prolonged exposure to heat, maybe a poorly made insulator may have loosened. Or possibly build up of moisture in a connector because of manufacturing fault?
Usually the connectors are supposed to be weather proof. It's possible a gland may have been breached and moisture got in.

Could be anything, but i would speculate that heat was involved...

[zibby43]

I don't know to be honest, but i can imagine with prolonged exposure to heat, maybe a poorly made insulator may have loosened. Or possibly build up of moisture in a connector because of manufacturing fault?
Usually the connectors are supposed to be weather proof. It's possible a gland may have been breached and moisture got in.

Thank you for the insight! I had initially assumed the short circuit would've been most likely to occur earlier.

[NL_Fer]

A burned coil or are they piëzo injectors?