I wouldn’t limit it to axial flux motors only, but I would like it if they developed them for F1 applications.
Maybe some use them now for one of the motors.DenBommer wrote: ↑03 Aug 2025, 22:49I wouldn’t limit it to axial flux motors only, but I would like it if they developed them for F1 applications.
Yes - but he didn't say "restrict"
Okay so what's the advantage? I4 is long and slim, V4 is small and short.
He said axial-flux specifically an nothing else. No reason to argue about this.
Yes, but slimmer is better for aero, or alternatively you can package more stuff to the sides. And with for example aforementioned axial flux design an electric motor can be very short.
Not really. Your airbox and exhaust manifold will be located higher on an Inline engine and will ultimately fill space higher up than a V.mzso wrote: ↑04 Aug 2025, 13:44He said axial-flux specifically an nothing else. No reason to argue about this.
Yes, but slimmer is better for aero, or alternatively you can package more stuff to the sides. And with for example aforementioned axial flux design an electric motor can be very short.
It seems like to me it's a choice based on how good you can design other aspects of the engine and how do you want to package it inside the car.
What other types of electric motors could they use? Apart from axial flux?mzso wrote: ↑04 Aug 2025, 13:44He said axial-flux specifically an nothing else. No reason to argue about this.
Yes, but slimmer is better for aero, or alternatively you can package more stuff to the sides. And with for example aforementioned axial flux design an electric motor can be very short.
It seems like to me it's a choice based on how good you can design other aspects of the engine and how do you want to package it inside the car.
It's more like a layout then motor type. You can have axial and radial. Axial flux motors are basically disk shaped, radials are cylinder shaped. As far as I know axial flux motors have a better power to weight/volume ratio.
I don't know. Gruntguru talked up V4 engines (versus straight 4), but I see no evidence of any used in F1. Meanwhile there were multiple independent i4 engines, BMW and Coventry-Climax engine powered cars having won F1 championships.
disc shaped motors are inferior in response ie when the PU is maximally accelerating/decelerating for gearshiftsmzso wrote: ↑06 Aug 2025, 16:07... Axial flux motors are basically disk shaped, radials are cylinder shaped. As far as I know axial flux motors have a better power to weight/volume ratio.
... there were multiple independent i4 engines, BMW and Coventry-Climax engine powered cars having won F1 championships.
Not that I'm advocating for either, but why are they inferior in response?Tommy Cookers wrote: ↑06 Aug 2025, 17:44disc shaped motors are inferior in response ie when the PU is maximally accelerating/decelerating for gearshifts
direct-drive isn't a USP here because gear reduction between MGU-K and PU is needed anyway (with either motor type)
I think in the high reving NA era killed the approach with low number of cylinders and by the time BMW came back V10 was mandatory anyway. But if revs would stay low (with forced induction) i4/V4 would still be options nowadays.Tommy Cookers wrote: ↑06 Aug 2025, 17:44the I4 BMW and C-C were in design bound to existing production engines
later both companies chose V8, V10, or 16 cylinders having then given themselves a clean sheet of paper
the I4 is also unhelpful to the structural design of the modern car
<Personal stuff removed>
a disc-shaped motor will have a large diameter 'rotor' of small axial lengthmzso wrote: ↑06 Aug 2025, 20:48... why are they inferior in response?Tommy Cookers wrote: ↑06 Aug 2025, 17:44disc shaped motors are inferior in response ie when the PU is maximally accelerating/decelerating for gearshifts
direct-drive isn't a USP here because gear reduction between MGU-K and PU is needed anyway (with either motor type)
I don't think the requirement for reduction is strictly a must.
Hm. I wonder if a compound axial motor could be a different (viable) solution to the problem. Small diameter rotor with multiple rotor discs. Maybe cancel out the need for gears, if good enough.Tommy Cookers wrote: ↑08 Aug 2025, 12:00a disc-shaped motor will have a large diameter 'rotor' of small axial lengthmzso wrote: ↑06 Aug 2025, 20:48... why are they inferior in response?Tommy Cookers wrote: ↑06 Aug 2025, 17:44disc shaped motors are inferior in response ie when the PU is maximally accelerating/decelerating for gearshifts
direct-drive isn't a USP here because gear reduction between MGU-K and PU is needed anyway (with either motor type)
I don't think the requirement for reduction is strictly a must.
this means (relatively) large inertia and so (relatively) poor response
small diameter and larger axial length will do the same motor job but has (relatively) less inertia so a better response
the F1 PU needs to accelerate/decelerate c.1000 ICE crank rpm in c.5 millisec for good behaviour during gear-shifts
ie the MGU-K is a liability unless it is energised to do this and highly responsive
the responsiveness is better with mechanical reduction as eg the PU inertia will be much less of a load on the MGU-K
basically - if the acceleration-related load is high mechanical reduction is highly beneficial/necessary
the response time of a motor is quantified as its electro-mechanical time constant (a few or a few tens of millisecs)
such a low time constant demands a very low electro-magnetic time constant - this has practical drawbacks
the road EV avoids needing such responsiveness
But wouldn’t you actually end up with more “engines”? If you know what I mean. The fewer engines you have, the simpler it becomes and the less chance there is for something to break down, right?mzso wrote: ↑08 Aug 2025, 16:45Hm. I wonder if a compound axial motor could be a different (viable) solution to the problem. Small diameter rotor with multiple rotor discs. Maybe cancel out the need for gears, if good enough.Tommy Cookers wrote: ↑08 Aug 2025, 12:00a disc-shaped motor will have a large diameter 'rotor' of small axial length
this means (relatively) large inertia and so (relatively) poor response
small diameter and larger axial length will do the same motor job but has (relatively) less inertia so a better response
the F1 PU needs to accelerate/decelerate c.1000 ICE crank rpm in c.5 millisec for good behaviour during gear-shifts
ie the MGU-K is a liability unless it is energised to do this and highly responsive
the responsiveness is better with mechanical reduction as eg the PU inertia will be much less of a load on the MGU-K
basically - if the acceleration-related load is high mechanical reduction is highly beneficial/necessary
the response time of a motor is quantified as its electro-mechanical time constant (a few or a few tens of millisecs)
such a low time constant demands a very low electro-magnetic time constant - this has practical drawbacks
the road EV avoids needing such responsiveness
Perhaps, or you can look at it as a motor with more parts. Doesn't seem to be much different for me than having a larger diameter motor with more magnets and coils. It's just in a different layout.