Honda Power Unit Hardware & Software

[saviour stivala]

“The torque at start is that of PU (ICE+MGU-K)”. At start the torque is that of ICE alone, when the MGU-K is allowed to kick-in they would most probably already have up-shifted into second gear.

[etusch]

“The torque at start is that of PU (ICE+MGU-K)”. At start the torque is that of ICE alone, when the MGU-K is allowed to kick-in they would most probably already have up-shifted into second gear.

Before mgu-k they couldn't use full engine power with nas engines until 140 km/h. Now there is more power at lower rpm with higher torq. According to what I read about Honda Engine they are using mgu-k to generation at least until that speed. It is some kind of TC contrl Engine power and store some of unneeded engine power to use later.

[henry]

“The torque at start is that of PU (ICE+MGU-K)”. At start the torque is that of ICE alone, when the MGU-K is allowed to kick-in they would most probably already have up-shifted into second gear.

How do you think that affects the arguments I made in the rest of my post?

Don’t worry I won’t hold my breath.

[subcritical71]

Before mgu-k they couldn't use full engine power with nas engines until 140 km/h. Now there is more power at lower rpm with higher torq. According to what I read about Honda Engine they are using mgu-k to generation at least until that speed. It is some kind of TC contrl Engine power and store some of unneeded engine power to use later.

https://youtu.be/VxwyM_fo8Ss

**moved from another thread... don't know how it got misplaced**
Just to clarify, they cannot use the MGU-K as traction control (although it would be technically possible), but as you say there is no reason the torque controller cannot generate from the MGU-K during traction limited acceleration (ie. increased ICE output and K harvesting). The ECU can determine where and what percentage of the delivered torque is from between the K and ICE. It's all in the pedal map which corresponds to the current strategy implemented. As long as the pedal map and total (PU) torque match it's all well within the rules.

[Tommy Cookers]

afaik
s s hasn't shown us any evidence supporting his view ....
that the clutch isn't 'used' after the first corner

during the recent thread lock I was trying to say that ...
the modern position of the clutch body (on the gearbox not the crankshaft) is consistent with the above 's s doctrine'

iirc I have not had any view (prior to my recent mention of the 2009 Honda paper) on this factor
the original and perennial controversy being over the meaning of the 'zero shift' claim
I suggest quasi-zero shift is a more accurate term
the shift doesn't solve the problem - it passes the problem downstream

whatever is/was done these issues were surely greater in the '20000 rpm' 3 litre V10 days than they are today

btw I have had an Italian car clutch and a British motorcycle clutch that did exactly what s s declares is impossible
lasted thousands of miles when continuous slipping would appear or be avoided according to use of throttle
and of course a helicopter must stay on the ground for inspection unless its clutch slips big-time

[Tommy Cookers]

sounds like you don't understand that for a required axle torque you can operate the engine ....
conventionally ie a normal gear and normal rpm giving normal (quite high) crankshaft/clutch torque or ...
unconventionally ie a low gear and high rpm giving abnormally low crankshaft/clutch torque
yes you use a higher gear when going downhill than the gear used when going uphill or when accelerating on the level

car (AlfaSud) I sold (with disclosure) for £20 - the buyer did 1000 miles then lent it to someone who blew the clutch in 5 min
the motorcycle (bought from new) had an unhardened clutch body which wore so that eventually only 1 plate worked

accelerating (slowly) you back off the throttle to keep torque low enough to avoid slip
you can't do this in a helicopter or you'll never accelerate the rotor
accelerating the rotor the clutch slip shows via 2 tacho needles - engine rpm and rotor rpm converted to engine-rpm equivalent

[henry]

The numbers are different to your gut feel unfortunately. Using a low rotational inertia for the engine plus MGUK of 0.05 kg.m^2 and a rpm change on upshift from 12,000 to 10,500 we get a change in kinetic energy of 18 kJ. (To achieve this in 1 second would require a braking power of 18 kW). The MGUK has a power limit of 120 kW so it will slow the engine from 12,000 to 10,500 in 0.15 sec (150 ms). That is way too slow for a gearshift. If the shift was say 15 ms, the braking power required to slow the engine would be 1200 kW.

@SS.
18 kJ (actually something less) per gearshift would not destroy the clutch over the course of a race.

For the gearchanges that happen when consistent traction is useful to the driver, in and around corners, I think it would be useful to maintain constant power. Assuming in qualification the power from the PU prior to the shift is 660kW then the PU could be switched off for 27msec, during which the 18kJ of inertial energy could provide the 660kW, and then the PU could pick up where it left off.

Obviously that’s not what happens but a combination of reduced or even negative PU, plus some clutch slip to vary the gear ratio and extend the change time might be useful to achieve constant power, if that is a useful goal.

An implication might be that change time would be different for each power output level the PU is targeting.

Another implication is that it might be useful to arrange the power curve so that the output is the same before and after gearchanges. When I looked at Ferrari’s power curve a couple of years ago that is roughly what I saw.

[gruntguru]

Another implication is that it might be useful to arrange the power curve so that the output is the same before and after gearchanges.

Definitely useful:
1. Equal power before and after the gearchange means equal torque/tractive effort at the tyre - clearly easer for the driver to manage.
2. The part of the power band which should be used is the peak power region. It follows hat the upshift should be made after the power peak and the revs should fall to a point below the power peak. In most cases the power level immediately before the shift will be very similar to the power level immediately after the shift. (The most common exception is a rev limit which applies while the power is still rising.)

[restless]

Something similar to
"It is useless to argue with someone who knows everything"
and
"Never argue with an idiot...."

I'm not quite sure its ok to post insults using non-english language as admin-deflector

[dren]

Another implication is that it might be useful to arrange the power curve so that the output is the same before and after gearchanges.

Definitely useful:
1. Equal power before and after the gearchange means equal torque/tractive effort at the tyre - clearly easer for the driver to manage.

These ICE should have a fairly flat power band in the upper rev range when accelerating. The MGUK could be used to make things equal.

[digitalrurouni]

https://www.motorsport.com/f1/news/hond ... y/4392892/

I mean Honda has been massively improved this year. I somehow believe Gasly. However despite the straight line speed Ferrari is demonstrating I think yes their PU is a bit far ahead but it's their aero that's affecting the top speed more than just straight line grunt and deployment IMHO.

[j.yank]

Before mgu-k they couldn't use full engine power with nas engines until 140 km/h. Now there is more power at lower rpm with higher torq. According to what I read about Honda Engine they are using mgu-k to generation at least until that speed. It is some kind of TC contrl Engine power and store some of unneeded engine power to use later.

You mean to use MGU-K in generation mode during accelartion in order to simulate something like pasive traction control?

[Tommy Cookers]

.... use MGU-K in generation mode during accelartion in order to simulate something like pasive traction control?

action of ICE and MGU-K combined should be mapped to comply with the accelerator pedal-to-PU torque map rules
ie the PU torque for a given accelerator position can't fall quicker than rpm rises - a constant power map as allowed in NA F1
(presumably constant though no-one here seems to have checked this exactly from the slope limit given in the rules)

the K's dynamic behaviour might collapse (and recover) its torque (driving or generating) if triggering factors were encountered
eg if there was a sudden change in eg wheel grip (driving or braking)
accelerating whilst K-driving would give a weak TC-like effect but accelerating while K-generating would give anti-TC
and braking while K-generating would give a weak ABS-like effect
I think
these dynamic response effects might not be seen as breaking the rules on mapping

[Zynerji]

.... use MGU-K in generation mode during accelartion in order to simulate something like pasive traction control?

the action of the ICE and the MGU-K combined should always comply with the accelerator pedal-to-PU torque map rules
ie the PU torque for a given accelerator position can't fall quicker than rpm rises - a constant power map as allowed in NA F1
(presumably constant though no-one here seems to have checked this exactly from the slope limit given in the rules)

the K's dynamic behaviour might collapse (and recover) its torque (driving or generating) if triggering factors were encountered
eg if there was a sudden change in eg wheel grip (driving or braking)
these dynamic response effects (somewhat like TC and even ABS) might not be seen as breaking the rules on mapping
and anyway they would be limited due to the limited size of the K

I think with the PU control maps, and "Diff magic" that the 2019 cars are probably light years ahead in "driver assistance" than the 2007 cars...

Sadly, this is probably the most "road relevant" tech in Formula 1.

[Nonserviam85]

Something similar to
"It is useless to argue with someone who knows everything"
and
"Never argue with an idiot...."

I'm not quite sure its ok to post insults using non-english language as admin-deflector

Never argue with an idiot, they will drag you to their level and beat you due to their experience...