Honda Power Unit Hardware & Software

[KurtMoran]

Explained in much more detail in this youtube video:
https://www.youtube.com/watch?v=VUgvhnQawbw

So far I've not yet heard of anyone reverse engineering the new f1 app to extract all the possible data. It was possible on the old days, not so much now.

Hey there, that's my video! I've browsed here before but never made an account but figured I would for this. I just wanted to make clear that I am not the author of that WordPress page.

As for how the distance is accounted for that is something I'm working on. The data in the video is synced up to be just 1 lap based on when the F1 app displays the last laps lap time. However, this sometimes has a variable delay from when the lap is completed to when the data is shown causing it to not sync perfectly. A few ways I'm thinking of is calculating distance with the known velocity information like another user mentioned or editing the video itself to start and stop based on the dots location hitting the start finish line on the video.

Any questions feel free to ask!

[saviour stivala]

we know the clutch has for years been slipped in a finely controlled way (to minimise the disruptive effects of shifts)
eg during upshifts clutch torque transmission capability is varied at about 8 millisec periodicity
this work dumped as slip friction is quite small

just guessing, cyclic clutch slipping at eg 1 Hz would involve far more slip work, and produce far more heat and wear

Incredible to suggest that on a F1 car were upshifts are made without the driver lifting throttle and with a power unit approaching the 1000hp output the clutch is ‘slipped’ to minimize the disruptive effects of shifts during upshifts.

[Zynerji]

we know the clutch has for years been slipped in a finely controlled way (to minimise the disruptive effects of shifts)
eg during upshifts clutch torque transmission capability is varied at about 8 millisec periodicity
this work dumped as slip friction is quite small

just guessing, cyclic clutch slipping at eg 1 Hz would involve far more slip work, and produce far more heat and wear

Incredible to suggest that on a F1 car were upshifts are made without the driver lifting throttle and with a power unit approaching the 1000hp output the clutch is ‘slipped’ to minimize the disruptive effects of shifts during upshifts.

Isn't this well documented in motorcycles already? Not a far stretch in my opinion...

[roon]

Explained in much more detail in this youtube video:
https://www.youtube.com/watch?v=VUgvhnQawbw

So far I've not yet heard of anyone reverse engineering the new f1 app to extract all the possible data. It was possible on the old days, not so much now.

Hey there, that's my video! I've browsed here before but never made an account but figured I would for this. I just wanted to make clear that I am not the author of that WordPress page.

As for how the distance is accounted for that is something I'm working on. The data in the video is synced up to be just 1 lap based on when the F1 app displays the last laps lap time. However, this sometimes has a variable delay from when the lap is completed to when the data is shown causing it to not sync perfectly. A few ways I'm thinking of is calculating distance with the known velocity information like another user mentioned or editing the video itself to start and stop based on the dots location hitting the start finish line on the video.

Any questions feel free to ask!

Welcome to the forum. I didn't write that, rather it was user Juzh. Link:

viewtopic.php?p=832604#p832604

[Tommy Cookers]

we know the clutch has for years been slipped in a finely controlled way (to minimise the disruptive effects of shifts)
eg during upshifts clutch torque transmission capability is varied at about 8 millisec periodicity
this work dumped as slip friction is quite small

Incredible to suggest that on a F1 car were upshifts are made without the driver lifting throttle and with a power unit approaching the 1000hp output the clutch is ‘slipped’ to minimize the disruptive effects of shifts during upshifts.

saviour stivala ....
you are saying that what I have written is not to be believed

what I have written is the gist of a paper in the Honda R & D Technical Revue 2009
'development of gearbox control during Honda Formula one third era'

you should read it

[saviour stivala]

What you have written (1990 era developments) is totally misleading as regards systems used and their permitted use in 2019. And for the benefit of those reading, those system/s used 30 years ago were/was no clutch-slip systems (slip between clutch friction plates and pressure plate/s), but a system of one-way-clutch which allowed the engaging of the next gear while the car is being driven in the present gear.

[Gibbs]

What you have written (1990 era developments) is totally misleading as regards systems used and their permitted use in 2019. And for the benefit of those reading, those system/s used 30 years ago were/was no clutch-slip systems (slip between clutch friction plates and pressure plate/s), but a system of one-way-clutch which allowed the engaging of the next gear while the car is being driven in the present gear.

The Honda R&D Technical Review F1 Special is a 376 page technical document that was published in 2009. It is (to my knowledge) the only recent document detailing the complete design of a modern F1 car.

[saviour stivala]

What you have written (1990 era developments) is totally misleading as regards systems used and their permitted use in 2019. And for the benefit of those reading, those system/s used 30 years ago were/was no clutch-slip systems (slip between clutch friction plates and pressure plate/s), but a system of one-way-clutch which allowed the engaging of the next gear while the car is being driven in the present gear.

The Honda R&D Technical Review F1 Special is a 376 page technical document that was published in 2009. It is (to my knowledge) the only recent document detailing the complete design of a modern F1 car.

Gibbs. Totally agree.

[Tommy Cookers]

What you have written (1990 era developments) is totally misleading as regards systems used and their permitted use in 2019. ....And for the benefit of those reading ...

rubbish !!
please benefit those reading by explaining how the 2009-era feature that I outlined isn't permitted now

[saviour stivala]

As I said the Honda paper does not speak of clutch slip but of a one-way-clutch. For an experienced poster to suggest the use of controlled clutch-slip for up-sifts, shifts that are made under full power is to me simply incredible.

[Tommy Cookers]

clearly you haven't properly read the paper of the title that I gave - or looked at the data plots in it
there's other papers about earlier aspects of transmission operation
and you still need to explain the basis of your incredulity

control of clutch-transmitted torque involves a torque sensor and an electro-hydraulic servo actuator
to vary clutch pressure (and transmitted torque) in milliseconds
ie controlled clutch slip smoothing upshifts sufficiently (but without wasting much of the energy stored in PU rotation rpm)

I didn't say anything about full power during shifts
the paper claims continuous (ie uninterrupted but not necessarily constant) acceleration
it doesn't claim that there's perfect conversion of full power (or some other power) to acceleration during upshifts
to me Honda seems to keep quiet about what it did to the V8 ICE during upshifts

[saviour stivala]

clearly you haven't properly read the paper of the title that I gave - or looked at the data plots in it
there's other papers about earlier aspects of transmission operation
and you still need to explain the basis of your incredulity

control of clutch-transmitted torque involves a torque sensor and an electro-hydraulic servo actuator
to vary clutch pressure (and transmitted torque) in milliseconds
ie controlled clutch slip smoothing upshifts sufficiently (but without wasting much of the energy stored in PU rotation rpm)

I didn't say anything about full power during shifts
the paper claims continuous (ie uninterrupted but not necessarily constant) acceleration
it doesn't claim that there's perfect conversion of full power (or some other power) to acceleration during upshifts
to me Honda seems to keep quiet about what it did to the V8 ICE during upshifts

Ok, I thought that you was confusing Honda developed one-way-clutch system for their claimed first in F1 seamless shift gearbox with actual engine clutch slip. So back to the actual engine clutch. The Honda paper doesn’t talk about finely controlled clutch slip during shifts to minimize the disruptive effects of shifts. Honda developed their clutch for controlled slip abilities for race starts and not for minimizing disruptive effects of gear shifts, this they did when they changed from a “dump-clutch race start system” to a “controlled clutch-slip race start system” in the “dump-clutch race start system” there is hardly any clutch-slip if ever but in 99% of starts the system will produce instead “wheel-slip” and that will not result in the fastest way off-the line. It is a well-known fact that the biggest enemy of a clutch is the race start because of the induced clutch-slip. The fact that a full race distance can see up to 47 gearshifts per lap. Increase by 10% to account for gear change while defending or overtaking or close calls and pit stops. And work out the average total for a race distance, and then try figure out how long the clutch will last with controlled slip for gear-shifts. That is exactly why I was surprised by you advocating the use of “finely controlled clutch-slip during shifts to minimize the disruptive effects of shifts”. In short, to me a sequential type seamless shift (no loss of power or requirement of clutch after first gear race start).

[MtthsMlw]

@RaceEngReports

[saviour stivala]

Superb detail photo.

[Tommy Cookers]

.... It is a well-known fact that the biggest enemy of a clutch is the race start because of the induced clutch-slip. The fact that a full race distance can see up to 47 gearshifts per lap. Increase by 10% to account for gear change while defending or overtaking or close calls and pit stops. And work out the average total for a race distance, and then try figure out how long the clutch will last with controlled slip for gear-shifts. That is exactly why I was surprised by you advocating the use of “finely controlled clutch-slip during shifts to minimize the disruptive effects of shifts”.

In short, to me a sequential type seamless shift (no loss of power or requirement of clutch after first gear race start).

your last sentence suggests that you believe in magic beans and free lunches (as many seem to do in this area of the car)

the slip work I suggest is per shift event a fraction of a fraction of a fraction of the slip work in per race start event
so yes the clutch could do this throughout the race
this would be less than one thousandth of the slip work done per race by each of those slip work devices that we call brakes

'my' management of clutch-transmitted torque helps to avoid distress (eg driveline misbehaviour often reported in this thread)
of course it requires development/adjustment as there are many interrelated and potentially conflicting factors in play
management is primarily to avoid unsuitable rates of change of transmitted torque
and I have never suggested that the PU torque isn't modified as part of the shift process

btw
helicopters slip their rotor drive clutches at full torque for one or two minutes before every flight
this is like a race start (but lasting one or two minutes)