Honda Power Unit Hardware & Software

[Airshifter]

‘’It seems that they have run out of fuel’’ Not only sounds like it, it also looks like it. But in actual fact they did not run out of fuel, because if they did we would have heard/read about the stewards not being able to extract the mandatory litre of after race fuel sample. As said by MV. Fuel was not getting to the engine, and as per Horner. The problem might be fuel lift pump, fuel pod or the E10 fuel itself (fuel temerature).

Would they be subject to the fuel test if they did not finish?

I suspect they would still be subject to the fuel test. The technical regs have a mention about cars not making it back to the pits after a practice, and I can't see why that wouldn't apply to a race as well.

From the technical regs, appropriate section quoted in full for clarity on the issue....

"6.5 Fuel draining and sampling
6.5.1 Competitors must provide a means of removing all fuel from the car.
6.5.2 Competitors must ensure that a 1.0 litre sample of fuel may be taken from the car at any time
during the Competition.
After a practice session, if a car has not been driven back to the pits under its own power, it
will be required to supply the above mentioned sample plus the amount of fuel that would
have been consumed to drive back to the pits. The additional amount of fuel will be
determined by the FIA.
6.5.3 All cars must be fitted with a –2 'Symetrics' male fitting in order to facilitate fuel sampling. If
an electric pump on board the car cannot be used to remove the fuel an externally connected
one may be used provided it is evident that a representative fuel sample is being taken. If an
external pump is used it must be possible to connect the FIA sampling hose to it and any hose
between the car and pump must be -3 in diameter and not exceed 2m in length. Details of
the fuel sampling hose may be found in the Appendix to the Technical and Sporting
Regulations.
6.5.4 The sampling procedure must not necessitate starting the engine or the removal of bodywork
(other than the nosebox assembly and the cover over any refuelling connector)."



I personally tend to think that whatever the full problem was at RB is more than is being spoken about. With all the telemetry coming off the car, they would have seen very quickly is the car was being fuel starved. Being that lean mixtures can do damage fairly quickly, I'm sure they would have had immediate warnings for any fuel cut outs taking place.

Granted they might speak about the issue on the radio, but chances are they would be at least changing mapping modes, going to a lower fuel demand, or most likely retiring the car.

[mzso]

Why is there still argument about fuel running? Wasn't it pretty much confirmed that the spec fuel pumps failed?

I suspect they would still be subject to the fuel test. The technical regs have a mention about cars not making it back to the pits after a practice, and I can't see why that wouldn't apply to a race as well.

Because it's pointless? Even if they were required, why would they bother? Getting a DSQ instead of a DNF. Wouldn't be worth the bother and the waste of time to give the car to the FIA.

[Hoffman900]

Why is there still argument about fuel running? Wasn't it pretty much confirmed that the spec fuel pumps failed?

I suspect they would still be subject to the fuel test. The technical regs have a mention about cars not making it back to the pits after a practice, and I can't see why that wouldn't apply to a race as well.

Because it's pointless? Even if they were required, why would they bother? Getting a DSQ instead of a DNF. Wouldn't be worth the bother and the waste of time to give the car to the FIA.

It’s just a rumor like anything else. Scarbs shared some background on some issues and people ran with that.

[ryaan2904]

Why is there still argument about fuel running? Wasn't it pretty much confirmed that the spec fuel pumps failed?

I suspect they would still be subject to the fuel test. The technical regs have a mention about cars not making it back to the pits after a practice, and I can't see why that wouldn't apply to a race as well.

Because it's pointless? Even if they were required, why would they bother? Getting a DSQ instead of a DNF. Wouldn't be worth the bother and the waste of time to give the car to the FIA.

The fuel pump issue is the most probable one, since it was a legitimate problem recognized by the fia before the race. Also, it was reported by Scarbs and AmuS.
Something other than this (not fuel pumps) was reported by motorsport italy first I think. Today there are rumors circulating that RB knowingly filled the car with less fuel to counter the extra weight.

So at this point I guess, you could pick your choice on who to trust. Even I'm not so sure about what exactly happened to be honest. All I can say is horner defo can't be trusted since anything other than fuel pump, which is a spec part, he won't reveal. That's giving away potential info to enemy teams.

[PhillipM]

I'll stick with my original theory, since it came on info from someone in the paddock, although admittedly from someone in a different team.
It is fuel pumps, but RB/Honda's high pressure ones on the cam drive, and connected to the hydraulic issue with Max's steering since that pump is on the same drive system.

[TNTHead]

I'll stick with my original theory, since it came on info from someone in the paddock, although admittedly from someone in a different team.
It is fuel pumps, but RB/Honda's high pressure ones on the cam drive, and connected to the hydraulic issue with Max's steering since that pump is on the same drive system.

High pressure pumps are very sensitive to fuel quality (which should be of no concern in F1), but also lubrication because of very tight tolerances. You suggest that lubrication might be insufficient with the Honda/Exxon E10 fuel spec?

[ryaan2904]

I'll stick with my original theory, since it came on info from someone in the paddock, although admittedly from someone in a different team.
It is fuel pumps, but RB/Honda's high pressure ones on the cam drive, and connected to the hydraulic issue with Max's steering since that pump is on the same drive system.

Damn. Another good theory. I really don't know what to believe now

[PhillipM]

High pressure pumps are very sensitive to fuel quality (which should be of no concern in F1), but also lubrication because of very tight tolerances. You suggest that lubrication might be insufficient with the Honda/Exxon E10 fuel spec?

They had problems with resonance/fatigue damaging the oil pumps up there in testing which they thought they'd fixed, speculating it's the same thing based on someone in the paddock at the time telling me that's what had failed shortly after the cars retiring. Nothing confirmed but it's plausible. Matches with the hydraulics slowly going on the power steering.
Would explain why it's only the RB cars.

I think we'll find out if they have to change anything though as they'll have to declare it anyway so shouldn't need to speculate for too long

[Hoffman900]

High pressure pumps are very sensitive to fuel quality (which should be of no concern in F1), but also lubrication because of very tight tolerances. You suggest that lubrication might be insufficient with the Honda/Exxon E10 fuel spec?

They had problems with resonance/fatigue damaging the oil pumps up there in testing which they thought they'd fixed, speculating it's the same thing based on someone in the paddock at the time telling me that's what had failed shortly after the cars retiring. Nothing confirmed but it's plausible. Matches with the hydraulics slowly going on the power steering.
Would explain why it's only the RB cars.

I think we'll find out if they have to change anything though as they'll have to declare it anyway so shouldn't need to speculate for too long

That is interesting.

Many don’t realize that the cam driven fuel pumps and oil pumps serve secondary roles as camshaft dampers.

I wonder if it is something deeper routed in the engine causing these harmonics (firing order and the rapid combustion concept).

[TNTHead]

High pressure pumps are very sensitive to fuel quality (which should be of no concern in F1), but also lubrication because of very tight tolerances. You suggest that lubrication might be insufficient with the Honda/Exxon E10 fuel spec?

They had problems with resonance/fatigue damaging the oil pumps up there in testing which they thought they'd fixed, speculating it's the same thing based on someone in the paddock at the time telling me that's what had failed shortly after the cars retiring. Nothing confirmed but it's plausible. Matches with the hydraulics slowly going on the power steering.
Would explain why it's only the RB cars.

I think we'll find out if they have to change anything though as they'll have to declare it anyway so shouldn't need to speculate for too long

That is interesting.

Many don’t realize that the cam driven fuel pumps and oil pumps serve secondary roles as camshaft dampers.

I wonder if it is something deeper routed in the engine causing these harmonics (firing order and the rapid combustion concept).

Thats indeed interesting. If it is the high pressure fuel pumps I think prior to the failure one should hear differences in the noise of the combustion, because the pump pressure drops etc. Can anyone confirm this? That could support this hypothesis.

[glenntws]

They had problems with resonance/fatigue damaging the oil pumps up there in testing which they thought they'd fixed, speculating it's the same thing based on someone in the paddock at the time telling me that's what had failed shortly after the cars retiring. Nothing confirmed but it's plausible. Matches with the hydraulics slowly going on the power steering.
Would explain why it's only the RB cars.

I think we'll find out if they have to change anything though as they'll have to declare it anyway so shouldn't need to speculate for too long

That is interesting.

Many don’t realize that the cam driven fuel pumps and oil pumps serve secondary roles as camshaft dampers.

I wonder if it is something deeper routed in the engine causing these harmonics (firing order and the rapid combustion concept).

Thats indeed interesting. If it is the high pressure fuel pumps I think prior to the failure one should hear differences in the noise of the combustion, because the pump pressure drops etc. Can anyone confirm this? That could support this hypothesis.

Nope, you should and probably (if Honda engineers are clever enough to develop such a engine, then well...) would not notice it.

ECUs always (afaik) feature a lookup table for injector rail pressure (no matter if port or direct injection), where through some pretty simple algorithms the fuel injection duration gets increased and decreased depending on the currently existing pressure. The additional time needed during low pressure operation should be negligible, since the default injector throughput should be enough to offer a sufficient window for adaptation.

If, however, the pressure drop gets too strong and the fuel flow is suddenly not enough, the ECU should and (afaik) actually did (onboards sounds like that to me) de-rate the engine so that the pressure can be kept at a minimum acceptable level. If the pump (or it's drive, I would say the first one) is dead, the ECU will sense non-acceptable injector rail pressure and then will stop the engine operation, as doing anything else is literally the same as sitting on top of a dead horse and trying to really motivate it to stand up and move.

While some people said, that Perez electronics died during the spin - which I found very weird, since a dead engine should not result on car shutdown - I think that after everything I read and heard, it's safe to say that the engines are fine. They sounded perfectly well until they stopped. They for sure didn't go out on fuel, nobody - literally nobody - working in F1 in a position to decide on fuel load would do such a miscalculation.

Why the pumps failed.... I don't know. It can be loads of stuff. Maybe the cams on the shaft actuating the pump have to strong of a acceleration or Honda tried to go with a "more lobes, less lift" approach in order to try further stabilizing the fuel rail pressure (which I find very possible regarding their combustion concept) but it doesn't go well with the new pump since they are now not using Bosch anymore.... But it's weird. They should have seen it on the Dyno. Definetly. Maybe RB just f****d up the fuel system up to the PU, since AT didn't suffer such a failure.


And regarding Gaslys failure.... Well, that's just bad stuff from Honda. I hate to see that, they were so reliable last year. But they still have time to make up for that. Probably just too much hardcore weight reduction around the MGU-K. But things like that shouldn't happen to Honda anymore. Get it together guys.

EDIT: If the HP pump was the failure point, and not the internals failed, but the actuator "shaft" and it's spring (meaning: it got up to its failure point where it first didn't return the pump piston back quick enough and then in the worst case scenario broke), we could very well see an actually dead engine because of the debris that potentially had some revs time to cause havoc or straight up chilled the camshaft and the bearings by seizing up the pump actuator. Let's pray, that this is not what happened.

[AR3-GP]

I'll stick with my original theory, since it came on info from someone in the paddock, although admittedly from someone in a different team.
It is fuel pumps, but RB/Honda's high pressure ones on the cam drive, and connected to the hydraulic issue with Max's steering since that pump is on the same drive system.

Max didn't have a hydraulic issue with the steering. The track rod was damaged. Bent.

[loekf2]

I'll stick with my original theory, since it came on info from someone in the paddock, although admittedly from someone in a different team.
It is fuel pumps, but RB/Honda's high pressure ones on the cam drive, and connected to the hydraulic issue with Max's steering since that pump is on the same drive system.

Max didn't have a hydraulic issue with the steering. The track rod was damaged. Bent.

Correct, see the picture Scarbs posted. Happened after the second pitstop when he went to soft again.

[PhillipM]

Correct, see the picture Scarbs posted. Happened after the second pitstop when he went to soft again.

I've seen it, and I don't believe it or the reasoning behind it, it also wouldn't explain Max complaining of it getting worse and worse as loads went up.

[AR3-GP]

Correct, see the picture Scarbs posted. Happened after the second pitstop when he went to soft again.

I've seen it, and I don't believe it it also wouldn't explain Max complaining of it getting worse and worse as loads went up.

This isn't the thread for it, but the rod was likely bending more and more and that explains it. Once the steering arm becomes bent, the forces on the arm work to bend it more and more. Think of a paperclip. Push along the ends. Stiff. Now bend it some, then push on the ends (it bows more and more). That will explain why it was becoming more difficult for Max. Rods do not support much bending loads before deforming.

Sorry, not the thread for it really, but there.