Honda Power Unit Hardware & Software

[ArcticWolfie]

The problem isn't with the ICE, but the MGU-H, we only had one single ICE faliure during this season as far as I'm aware. The rest of the problems have been elsewhere, oil tank, hydraulics, shafts, bearings.

Vandoorne's spec 3.8 is essentially new cylinder heads.

Oil tank & hydraulics are specific ICE components I believe? But I agree, there were a lot more MGU-H/K/Turbo problems.

[McMika98]

[quote=Wazari post_id=725616 time=1508971470
[/quote]

The first issue I am told has been addressed. I have just been told about the MGU-H temps from engine telemetry and they are not in the "designed" range.

When the season is over I will go into detail as to the reason why the Spec 4 PU was not implemented this season from HRD and McLaren sources.
[/quote]

Mr Wazari, looking forward to hear your info. However it is clear that Spec 4 would not match Merc or Ferrari this year based on Hasegawa san's interviews. What i would be more interested is in Spec 5.0, the next step up. Come next year we will see a big leap from all three other manufacturers somehow, so is there a secret sauce that Honda is brewing for next year?

[63l8qrrfy6]

[...]
MGU-H bearing failure is a result of unforeseen multi-directional stress on the shaft and entire casing that houses the bearings.
[...]

Just a reminder of a previous post abut the MGU-H, to add to the latest.

Well spotted, I missed that!

The shaft ca be loaded in torsion, radially (bending) and axially (tension). Torsion does not affect bearings however both axial and radial loads are reacted by angular contact bearings. I suspect this is what Wazari means by multi directional stresses.

The axial loads are likely to be produced by the pressure acting on the compressor and turbine wheels, while radial loads are the result of unbalance, EMF and misalignment.

Another factor could be the mounting of the turbo and MGUH to the block. It is very bad practice to bridge the LH and RH banks in high performance Aluminium engines due to the high thermal expansion and Honda might have done just that.
In this case the housing will experience the loads reacted by the bearings as well as the thermal loads due to the block expansion.

[DFX]

If spec 4 was firstly planned to debut in SPA, why would the chassis implementation be so different from the actual car? Wouldnt Mclaren be already prepared to accomodate this PU before the partnership broke up?

Changing PU installation mid season makes any sense in development through a season?

Not trying to be mean, Im genuinely curious.

If the heads are larger (we've heard they cause the PU to have a higher CoG), then some cooling solutions on the chassis side may need to be rerouted or massaged a bit to get everything to fit. Mclaren may not want to put in the resources at this point for marginal gains that won't affect their standings in the championship. Just a guess.

I can understand that but it looks more like a contigency plan than a planned upgrade. My point being that Mclaren would have received the specs and dimensions of the new PU and prepare and manufacture the parts in advance to accomodate it, or this doesnt make sense?

With Alonso and Vandoorne taking new PU's, Vandoorne changing everything, is there any chance that we will see more upgrades? Even if its not spec 4?

[godlameroso]

[...]
MGU-H bearing failure is a result of unforeseen multi-directional stress on the shaft and entire casing that houses the bearings.
[...]

Just a reminder of a previous post abut the MGU-H, to add to the latest.

Well spotted, I missed that!

The shaft ca be loaded in torsion, radially (bending) and axially (tension). Torsion does not affect bearings however both axial and radial loads are reacted by angular contact bearings. I suspect this is what Wazari means by multi directional stresses.

The axial loads are likely to be produced by the pressure acting on the compressor and turbine wheels, while radial loads are the result of unbalance, EMF and misalignment.

Another factor could be the mounting of the turbo and MGUH to the block. It is very bad practice to bridge the LH and RH banks in high performance Aluminium engines due to the high thermal expansion and Honda might have done just that.
In this case the housing will experience the loads reacted by the bearings as well as the thermal loads due to the block expansion.

The only way would be to strengthen the block, or use a different metal/material with more favorable expansion properties as a sleeve housing for the bearing.

[63l8qrrfy6]

The only way would be to strengthen the block, or use a different metal/material with more favorable expansion properties as a sleeve housing for the bearing.

Well there's simpler solutions such as including a compliant element in the mounting (sometimes very tall bosses are sufficient) or moving the mounting points such that they do not experience relative deformation.

Modifying the block is anything but practical.

[McMika98]

There would be no Spec 5.0 since it will be an all new power unit, the Honda RA618H. It would be Spec 1 all over again. And the breath bating "Spec waiting game" will be there again too.

Well at least we are led to believe that next year, the engine will be similar in architechture if not same as current PU regardless of the designation. So whatever output 4.0 has the new engine must have further improvements be it reliability, enabling engine to run at higher modes.

[Wazari]

Mr Wazari, looking forward to hear your info. However it is clear that Spec 4 would not match Merc or Ferrari this year based on Hasegawa san's interviews. What i would be more interested is in Spec 5.0, the next step up. Come next year we will see a big leap from all three other manufacturers somehow, so is there a secret sauce that Honda is brewing for next year?

I can't answer that. I have a good idea of where the complete (new ICE, turbine, compressor, MGU-H unit and different harvesting and deployment philosophy) Spec 4 stands in terms of performance. I don't know where Mercedes and Ferrari quite stand currently. I am not aware of a "Spec 5".

I believe that between now and the end of the season, Honda will try and implement as many new components as time and McLaren will allow on the current Spec 3.XXXX platform. I fully expect the complete Spec 4 to be in the TR at winter testing. We shall see.

[63l8qrrfy6]

Steering away from the painfully interesting subject of Spec 4 - how is Honda's performance going to be affected by the high altitude ?

Their compressor has reportedly been smaller that the competitor's in the past, if this is still the case it may be running very close to (and potentially be impaired by) the turbo speed limit in Mexic ?

Is the compressor efficiency going to take a large enough hit to significantly affect performance ? Will the high turbo speed exacerbate bearing issues ? Will charge temps rocket?

[wuzak]

Their compressor has reportedly been smaller that the competitor's in the past, if this is still the case it may be running very close to (and potentially be impaired by) the turbo speed limit in Mexic ?

I thought that was the whole point of the major redesign for this year.

[godlameroso]

Steering away from the painfully interesting subject of Spec 4 - how is Honda's performance going to be affected by the high altitude ?

Their compressor has reportedly been smaller that the competitor's in the past, if this is still the case it may be running very close to (and potentially be impaired by) the turbo speed limit in Mexic ?

Is the compressor efficiency going to take a large enough hit to significantly affect performance ? Will the high turbo speed exacerbate bearing issues ? Will charge temps rocket?

Their compressor can easily deliver in excess of the boost pressures necessary. In order to maximize the potential of the ERS it has to be this way.

[GhostF1]

Is it feasible to assume this double MGU-H failure is due to the extremely bumpy nature of COTA?
They've had reasonable reliability and yet in the US both a used and a relatively new unit gave up.
Maybe the PU is still sensitive to external physical stress?

[ispano6]

Is it feasible to assume this double MGU-H failure is due to the extremely bumpy nature of COTA?
They've had reasonable reliability and yet in the US both a used and a relatively new unit gave up.
Maybe the PU is still sensitive to external physical stress?

This is what I thought as well. Sector 1 had some harsh bumps where the chassis seem to drop and bounce drastically.
Similar to Monza, where it seemed the same curb caused Vandoorne's MGU-K damage twice, the car bottoming out and sending the impact, vibration and torsional stress into the low COG PU is too much for the hardware. Vandoorne did manage to finish the race with decent pace and I'm thinking he probably avoided the worst parts of the track where the PU components were likely to incur damage.

[GhostF1]

Is it feasible to assume this double MGU-H failure is due to the extremely bumpy nature of COTA?
They've had reasonable reliability and yet in the US both a used and a relatively new unit gave up.
Maybe the PU is still sensitive to external physical stress?

This is what I thought as well. Sector 1 had some harsh bumps where the chassis seem to drop and bounce drastically.
Similar to Monza, where it seemed the same curb caused Vandoorne's MGU-K damage twice, the car bottoming out and sending the impact, vibration and torsional stress into the low COG PU is too much for the hardware. Vandoorne did manage to finish the race with decent pace and I'm thinking he probably avoided the worst parts of the track where the PU components were likely to incur damage.

Yes definitely S1, watching over Alonso's qualifying lap, the first sector looks really quite violent and mix that with Honda having issues earlier in the year with bumps and asking the drivers to avoid the ripple strips and any harsh jolts, it adds to the case it could still be a problem even with the fix they implemented.

Now I know Wazari said it is operating temp related and that the external force issue was sorted, but is it possible it hasn't been entirely rectified and just exacerbated by the surface condition here?

I don't like the idea of coincidence relating to operating temps for the same issue in two different cars, especially when reliability has arguably been stable compared to earlier in the season.

[bigblue]

Maybe they were just too optimistic / mis-estimated effects of this circuit on energy recovery and ran the components a bit more aggressively than turned out to be prudent ? Maybe cooling to the engine was marginal, since it wasn't quite set right (in hindsight). I'm not an F1 engineer, but there could be other reasons why both cars had failures rather than due to the bumps (that is another valid possibility, but doesn't agree with Wazari's information). Anyway, looks like lots of new components for both drivers. No information suggesting any new spec changes so far, but it's only early on Friday so far