Honda Power Unit Hardware & Software

[roon]

I spy two actuators on the compressor. One for wastegate, one for guide vanes. There's two metallic ancillary tubes connecting to the intake trumpet, one for wastegate, the other for...?

Variable intake runner actuator?

You can see the variable intake runner actuator on the back side of the intake plenum tucked between the runners.

I think he meant on the compressor inlet.

The black box at the top controls the crank case pressure and possible oil burning? You can see a black hose going from it down to the valve covers.

A good guess. Regs for 2018 suggest whatever is happening inside such a box to be passive. An open port, or regulator. By rules, this component/system has to be in place:

7.3 Catch tank :
In order to avoid the possibility of oil being deposited on the track, the engine sump breather must vent into the main engine air intake system.

The [Honda] intake trumpet/snorkel has a sharp 90* bend entering the compressor. The Merc PU uses a more gentle sweep.

https://i.imgur.com/e00yKX3.jpg

If this is the sort of packaging compromises McLaren imposed upon Honda, perhaps a switch to a new team is for the best. TR is known for experimentation, thus may be able to better accommodate Honda. As in, provide a chassis which doesn't require an engine intake bottleneck. Combined with the regulations on oil burning, Honda may be further advantaged. Might be good years ahead for them.

[godlameroso]

I think that the MGUH allows the turbo to operate in a very narrow window, therefore I am not sure that off design performance is as important as in a conventional turbo.
However I am inclined to believe that when compressor speed is 'artificially' kept high surge will inevitably occur at low flow rates (off or part throttle) and high pressure - Audi Quattro S1 was a notorious case with its umluft anti lag causing surge and grenading turbos.

Since in F1 they can't really afford compressor bypass valves due to efficiency losses, variable vane diffusers can be used to condition the flow at the impeller exit and shift the surge line further out. Efficiency wise variable inlet vanes are probably better at reducing compressor work - if I remember correctly there's more to be gained by altering the inlet velocity triangle.

Shame they can't bypass the excess into the turbine. Or into a pump that functions as an engine ancillary that gives the excess compressor air to the MGU-K via said pump.

[MrPotatoHead]

Since in F1 they can't really afford compressor bypass valves due to efficiency losses, variable vane diffusers can be used to condition the flow at the impeller exit and shift the surge line further out. Efficiency wise variable inlet vanes are probably better at reducing compressor work - if I remember correctly there's more to be gained by altering the inlet velocity triangle.

You can clearly see the Honda Compressor Bypass valve in the pictures shown. *shrugs*

Shame they can't bypass the excess into the turbine. Or into a pump that functions as an engine ancillary that gives the excess compressor air to the MGU-K via said pump.

5.13.1 All coolant pumps, oil pumps, scavenge pumps, oil/air separators, hydraulic pumps and fuel pumps delivering more than 10bar must be mechanically driven directly from the engine and/or MGU-K with a fixed speed ratio.

5.2.2 Energy flows, power and ES state of charge limits are defined in the energy flow diagram shown in Appendix 3 of these regulations.

Yepp. There are very specific rules that prohibit most of the things suggested or implied on this forum.

[63l8qrrfy6]

You can clearly see the Honda Compressor Bypass valve in the pictures shown. *shrugs*

I missed that, it's quite obvious now that you've mentioned it. I'm baffled now - surely that's a good amount of compressor work going down the drain

[MrPotatoHead]

You can clearly see the Honda Compressor Bypass valve in the pictures shown. *shrugs*

I missed that, it's quite obvious now that you've mentioned it. I'm baffled now - surely that's a good amount of compressor work going down the drain

Well if you think back to before 2014 - many speculated that they wouldn't need a Wastegate with the MGU-H. But the reality is quite the opposite.
I think the same is true of the bypass valve also - If the throttle plates were to close suddenly the the bypass valve will always control the resulting potential surge quicker than the MGU-H could, physics always wins

Yet another example of how mind bogglingly complex the control of these engines is. I love it.

[godlameroso]

Since in F1 they can't really afford compressor bypass valves due to efficiency losses, variable vane diffusers can be used to condition the flow at the impeller exit and shift the surge line further out. Efficiency wise variable inlet vanes are probably better at reducing compressor work - if I remember correctly there's more to be gained by altering the inlet velocity triangle.

You can clearly see the Honda Compressor Bypass valve in the pictures shown. *shrugs*

Shame they can't bypass the excess into the turbine. Or into a pump that functions as an engine ancillary that gives the excess compressor air to the MGU-K via said pump.

5.13.1 All coolant pumps, oil pumps, scavenge pumps, oil/air separators, hydraulic pumps and fuel pumps delivering more than 10bar must be mechanically driven directly from the engine and/or MGU-K with a fixed speed ratio.

5.2.2 Energy flows, power and ES state of charge limits are defined in the energy flow diagram shown in Appendix 3 of these regulations.

Yepp. There are very specific rules that prohibit most of the things suggested or implied on this forum.

Technically what I said would be legal, implementing it is difficult. As I said, as long as it's an "engine ancillary" you can have it tied into the mgu-k. AFAIK there is no rule preventing one from accumulating air pressure bled off the compressor. Only that air enters the engine from specified locations.

If you follow the energy flow chart, engine ancillaries are allowed to shuffle energy between the K the engine and pressure charging system, and the pressure charging system is allowed unlimited transfer to the H, as are other ancillaries delivering less than 10bar.

This way F1 can copy Volvo, as they do precisely this, accumulate excess compressor air in a pump and send it to the turbine to aid spool up. In F1 you have to do it indirectly though.

[PlatinumZealot]

If you follow the energy flow chart, engine ancillaries are allowed to shuffle energy between the K the engine and pressure charging system, and the pressure charging system is allowed unlimited transfer to the H, as are other ancillaries delivering less than 10bar.

This way F1 can copy Volvo, as they do precisely this, accumulate excess compressor air in a pump and send it to the turbine to aid spool up. In F1 you have to do it indirectly though.

Hold up.

Are you suggesting coupling an air motor on the MGUK?
Ahm.. OK... Let's explore.

1. Air motors need a big pressure differential to work.. Yes.. you do have this if you tie the air motor exhaust to the air inlet of the compressor.

2. When the driver is off throttle, he does not want this excess energy at the wheels, however since the MGUK also functions to charge the batteries it could absorb this energy if it switches to generator mode during this time.

3. How often will these boost spike events happen anyway and for long? Not very often. So there will be a weight penalty of carrying this extra hardware around. Maybe 1kg. Your boost spikes are all less than one second. Is this a significant contribution to overall fuel mileage at the end of a race?

4. The air motor's intake and exhaust piping will have to be closed to prevent windage loss when not in use.

[godlameroso]

You forget the large periods of full throttle. You rely on your wastegates, your MGU-H to harvest, and any excess boost pressure, instead of being bled to the atmosphere, is accumulated, this way you gain work from both turbine and compressor. Clearly these compressors are capable of delivering more than enough air, this way you can run the turbo at high speeds at all times without wasting anything. So the pump itself may not deliver much in terms of outright power, and add weight but you may benefit by being able to run the turbo at high speed for a higher percentage of time, which results in more ERS harvesting. This could be a net benefit as it allows longer deployment, longer deployment means more power. So peak power may not improve much, but peak sustained power may increase substantially.

You forget that these engines are so integrated that small changes can have big knock on effects. Especially small gains in efficiency here and there.

[MrPotatoHead]

The rules are very specific about where you can store compressed gas (for valve springs) and where the air and energy flows can be.
What you are describing is not legal.

[godlameroso]

It is. Look at where energy can be sent, like I said it's not illegal just an engineering challenge. There is no spirit of the rules, there are words, if you can show that you functionally comply with those words then what's the problem?

Unless you're talking about the special appendix to the regulations, because according to published regulations it's fine.

[hurril]

But... compressing this air does not come for free. Why not run the MGU-h "harder" directly instead of going the round about way via the MGU-k? The pop-off valve is for transient conditions of pressure spikes. I also think you'd learn that bleeding off the air leaves more work over for the MGU-h too since the compressor gets unloaded that way.

[godlameroso]

Yeah you're right, nm. Energy can go from the engine to the pressure charging system to the MGU-H in unlimited amounts, and in any direction, it's a waste to use an ancillary and add complexity. Why send energy through the MGU-K in order to send to the H, when you can send energy directly from the compressor to the H.

[PlatinumZealot]

You forget the large periods of full throttle. You rely on your wastegates, your MGU-H to harvest, and any excess boost pressure, instead of being bled to the atmosphere, is accumulated, this way you gain work from both turbine and compressor. Clearly these compressors are capable of delivering more than enough air, this way you can run the turbo at high speeds at all times without wasting anything.

I have to stop you right there. In steady conditions, no boost spikes or excess energy will be coming from the Compressor/turbine/MGUH. It is harvested to the battery according to ECU mapping. There is no excess boost pressure except for quick throttle blips and quick downshifts - where feed forward control algorithms would be used to predict these boost spikes; and I am only guessing that there is finite control in doing this. So, in that sense it is much more efficient to use the MGUH with a high priority if you can prevent boost spikes.
I only was entertaining your idea of using an air motor to scavenge compressed air for those transient conditions when boost spikes are inevitable, but I do not agree with your view that the excess boost is in ample supply. Producing excess boost just to recover it back is not efficient. Better to only produce as much boost as you need.

[godlameroso]

You forget the large periods of full throttle. You rely on your wastegates, your MGU-H to harvest, and any excess boost pressure, instead of being bled to the atmosphere, is accumulated, this way you gain work from both turbine and compressor. Clearly these compressors are capable of delivering more than enough air, this way you can run the turbo at high speeds at all times without wasting anything.

I have to stop you right there. In steady conditions, no boost spikes or excess energy will be coming from the Compressor/turbine/MGUH. It is harvested to the battery according to ECU mapping. There is no excess boost pressure except for quick throttle blips and quick downshifts - where feed forward control algorithms would be used to predict these boost spikes; and I am only guessing that there is finite control in doing this. So, in that sense it is much more efficient to use the MGUH with a high priority if you can prevent boost spikes.
I only was entertaining your idea of using an air motor to scavenge compressed air for those transient conditions when boost spikes are inevitable, but I do not agree with your view that the excess boost is in ample supply. Producing excess boost just to recover it back is not efficient. Better to only produce as much boost as you need.

That was the thinking that steered Honda to mounting the turbo within the V, we know how that turned out.

[MrPotatoHead]

You forget the large periods of full throttle. You rely on your wastegates, your MGU-H to harvest, and any excess boost pressure, instead of being bled to the atmosphere, is accumulated, this way you gain work from both turbine and compressor. Clearly these compressors are capable of delivering more than enough air, this way you can run the turbo at high speeds at all times without wasting anything.

I have to stop you right there. In steady conditions, no boost spikes or excess energy will be coming from the Compressor/turbine/MGUH. It is harvested to the battery according to ECU mapping. There is no excess boost pressure except for quick throttle blips and quick downshifts - where feed forward control algorithms would be used to predict these boost spikes; and I am only guessing that there is finite control in doing this. So, in that sense it is much more efficient to use the MGUH with a high priority if you can prevent boost spikes.
I only was entertaining your idea of using an air motor to scavenge compressed air for those transient conditions when boost spikes are inevitable, but I do not agree with your view that the excess boost is in ample supply. Producing excess boost just to recover it back is not efficient. Better to only produce as much boost as you need.

That was the thinking that steered Honda to mounting the turbo within the V, we know how that turned out.

No the problem is their calculations were way off so they needed a bigger compressor and had no more space for it there.