Honda Power Unit Hardware & Software

[Craigy]

I wonder if you could use aux current to induce current in the K output. That'd bypass the ES to K limit.

Would be against the K's 4MJ deployment limit.

ES-->MGUK is 4MJ
ES-->aux (non engine ancillaries) is unlimited

Sorry, you're quite right. I'm tired at the moment.

I was distracted by the difference in the energy flow diagram from 2020 to 2021 FIA technical regs.
For 2021, they've removed the box that says the ERS-H and ERS-K can drive "other ancillaries" at an unlimited rate. they've also reduced by 10x the amount of energy inside the MGU control unit (5kJ for 2020 to 500J 2021). There's also a change to the stationary charging of the battery text, with a specified limit of 100kJ (previously it said the amount of stored energy can't increase).

[PlatinumZealot]

I wonder if you could use aux current to induce current in the K output. That'd bypass the ES to K limit.

This idea has been floated on the forums a number of times... Very likely but it is less suspicious to do it via the MGUH to MGUK link. you wont get more than 120kW this way but at least you have more energy per lap.

MGUK power can be monitored even with a cheat circuit hooked up in parallel. Once you have one set of armature coils. This is done similar to a how a assynchronous machine is monitored (it chases grid frequency). They will know something is going on by comparing before and after effects on the wires. Thermals will be higher, speed current trace would be different, etc. So it might be safer to avoid increasing power and instead aim to increase energy over lap through the unregulated MGUH to MGUK connection.

[GhostF1]

That downshift bark we heard end of last season and pre season testing this year is back in FP1... interesting to note.

[dren]

I wonder if you could use aux current to induce current in the K output. That'd bypass the ES to K limit.

This idea has been floated on the forums a number of times... Very likely but it is less suspicious to do it via the MGUH to MGUK link. you wont get more than 120kW this way but at least you have more energy per lap.

MGUK power can be monitored even with a cheat circuit hooked up in parallel. Once you have one set of armature coils. This is done similar to a how a assynchronous machine is monitored (it chases grid frequency). They will know something is going on by comparing before and after effects on the wires. Thermals will be higher, speed current trace would be different, etc. So it might be safer to avoid increasing power and instead aim to increase energy over lap through the unregulated MGUH to MGUK connection.

Thanks, I haven't been around in a while and likely missed it.

[ispano6]

That downshift bark we heard end of last season and pre season testing this year is back in FP1... interesting to note.

Your observation is note-worthy.
I've re-watched the Asaki and Yamamoto interview and tried to get some inference as to what might be in store for Honda's PU modes moving forward, and has my attention on two things:
1) he says that lift and coasting is not really necessary anymore and that they will still be running to the 100kg/hr fuel flow rate. Perhaps two of the only reasons a team would need to lift/coast is if they opt to go with less starting fuel weight and during a safety car period. It's also possible to be disqualified from qualifying if you exceed the fuel flow rate so teams need to be careful to be within legal parameters calculated over one lap and over a race distance. Lifting and coasting may reduce the energy converted from heat (thermal efficiency), so software mapping will need to ensure optimal fuel flow rate and operating temperatures.
2) If lift and coasting becomes necessary from running lower weight with less starting fuel, then what happens off throttle while lifting becomes ever important and that is where Asaki's response to the unique Honda PU sound off throttle has me intrigued. Perhaps Honda is working to optimize off-throttle thermal efficiency?

[stevesingo]

I suppose the question is where the balance of performance is between lap time gained in the corners from running light on fuel against the lap time gained from being WOT for longer.

Run light on fuel = Lift and coast = higher corner speed, less tyre stress (may open up strategic options) marginally better acceleration/braking.

Run heavy on fuel = WOT for longer = higher terminal speed, more H harvest, more K harvest (braking from higher speed and/or, run as gen set for last part of the straight.

[Craigy]

I suppose the question is where the balance of performance is between lap time gained in the corners from running light on fuel against the lap time gained from being WOT for longer.

Run light on fuel = Lift and coast = higher corner speed, less tyre stress (may open up strategic options) marginally better acceleration/braking.

Run heavy on fuel = WOT for longer = higher terminal speed, more H harvest, more K harvest (braking from higher speed and/or, run as gen set for last part of the straight.

It's also a question of whether you want to be comparatively faster at the start of the race or not.
The biggest delta between a car on say 80kg of fuel at the start and one on say 100kg, would be lap 1. By the end of the race they'd both have converged down to only a kilo or two left, so in terms of time delta, it'd put all of that at the start of the race in favour of the lighter car.

[godlameroso]

I suppose the question is where the balance of performance is between lap time gained in the corners from running light on fuel against the lap time gained from being WOT for longer.

Run light on fuel = Lift and coast = higher corner speed, less tyre stress (may open up strategic options) marginally better acceleration/braking.

Run heavy on fuel = WOT for longer = higher terminal speed, more H harvest, more K harvest (braking from higher speed and/or, run as gen set for last part of the straight.

You're faster with more fuel. There's still some lift and coast, especially in races, but it's not done just for fuel saving. It's easier on the tires, as well, it's easier on the brakes. Driving this way is difficult and hard to see from onboards. Because if you lift too much for too long you go really slow. There's some DBW throttling used under braking on different ERS modes. The MGU-K under harvesting produces a strong negative torque which can cause a car to spin especially at slow speeds. A driver can use the throttle to counter this, however with the DBW controls the ECU can counter the MGU-K harvest torque on its own. It's not technically a driver aid, but it kind of falls into one because it can offer extra performance if a driver gets the hang of it.

Some interesting options arise with diff locking, MGU-K and ICE working together to control rear slip. In this, the driver can make a big difference with a certain driving style.

[Big Tea]

That downshift bark we heard end of last season and pre season testing this year is back in FP1... interesting to note.

Perhaps two of the only reasons a team would need to lift/coast is if they opt to go with less starting fuel weight and during a safety car period. It's also possible to be disqualified from qualifying if you exceed the fuel flow rate so teams need to be careful to be within legal parameters calculated over one lap and over a race distance. Lifting and coasting may reduce the energy converted from heat (thermal efficiency), so software mapping will need to ensure optimal fuel flow rate and operating temperatures.

Does this mean that teams sometimes DO exceed the flow rate?
I thought it was a fixed maximum with no (upward) variation?

I thought at first it was referring to getting too much from the H, but he specifically says flow rate.

I am being a bit thick here sorry

[stevesingo]

I suppose the question is where the balance of performance is between lap time gained in the corners from running light on fuel against the lap time gained from being WOT for longer.

Run light on fuel = Lift and coast = higher corner speed, less tyre stress (may open up strategic options) marginally better acceleration/braking.

Run heavy on fuel = WOT for longer = higher terminal speed, more H harvest, more K harvest (braking from higher speed and/or, run as gen set for last part of the straight.

You're faster with more fuel. There's still some lift and coast, especially in races, but it's not done just for fuel saving. It's easier on the tires, as well, it's easier on the brakes. Driving this way is difficult and hard to see from onboards. Because if you lift too much for too long you go really slow. There's some DBW throttling used under braking on different ERS modes. The MGU-K under harvesting produces a strong negative torque which can cause a car to spin especially at slow speeds. A driver can use the throttle to counter this, however with the DBW controls the ECU can counter the MGU-K harvest torque on its own. It's not technically a driver aid, but it kind of falls into one because it can offer extra performance if a driver gets the hang of it.

Some interesting options arise with diff locking, MGU-K and ICE working together to control rear slip. In this, the driver can make a big difference with a certain driving style.

I'm not sure I agree with you. Sure, it's easier on the brakes. WHat does that mean, lower temps thus lower wear? Modern F1 brakes can handle a full speed race without issue, providing the cooling is correct. Easier on the tyres? Would not expect the tyre life is extended by more than 2-4%. Although braking loads are high, they are short lived. Lift and coast would change the proportion of load more rearwards as the MGU-K acts on the rears only.

Fact is, 10kg is worth a fixed amount of lap time for a given circuit. The balance is between lap time gain due to lower weight and loss due to lift and coast.

[godlameroso]

For one, if it's easier on the brakes, less brake cooling is potentially needed. That has a drag benefit, you act like small changes in F1 are irrelevant yet teams spend millions shaving fractions off whatever.

[ispano6]

Race winning engine x2! Congratulations Honda! A Tale of Two outcomes but an awesome result and loads of good data.

Pierre was strong all weekend long, AT know their home track well, they've done their homework and Honda's race mode proved it can hold out.

Yamamoto said in that video interview with Asaki to look forward to the Monza race, I wonder if he knew what was in store. The FP2 racepace data looked good too.

[63l8qrrfy6]

I wonder if VER's PU issue is something that would have been easily fixed with some good old mode changes.

[McMika98]

Yamamoto said in that video interview with Asaki to look forward to the Monza race, I wonder if he knew what was in store.

Let's not go overboard with the 20-20 hindsight. Lewis blew the race, Gasly was being hounded by Kvyat before he pitted and lucked with the events following. There is no way Asaki would have seen this.
P7 was maximum that was on the cards before the series of events transpired.

If anything all engines are now almost at a level playing field bar Ferrari.

[ispano6]

I wonder if VER's PU issue is something that would have been easily fixed with some good old mode changes.

It's a moot point now that the TD is in place. I don't think these complex PUs can fix themselves from just switching modes unless it is purely software issue and not a hardware or sensor issue. They likely did the the prudent thing and turned it down and decided to limit any possible damage. Fortunately it wasn't terminal such that it just stopped out on track, and they still had 3 cars collecting data. Question is if they can identify the issue and be allowed to rectify it for PU3 if it is hardware related.

Max's start and restart were both pretty bad, so maybe there was an issue with the torque delivery and traction for the RB16. There was also a section where Max's rear right dropped into gravel taking a line that seemed a bit strange. I was worried that might have caused sensor issues. Also I was reminded of Dani's retirement last year at Monza where his car started puffing white smoke and I'm not certain if it was caused due to a radiator being punctured from gravel picked up when Albon was pushed wide. In today's race there was one time when Bottas kicked up a bit of gravel and Max drove through a cloud of it. We will probably find out if it was overheating or sensor issues or both.