2024 Powerboost eletric-gas transition: flywheel starter vs hybrid motor

[DeepBlue]

First time Powerboost owner here. Have been driving my 2024 Powerboost for a month now. I understand that the BISG has been removed from the 2024MY, thanks for the excellent analyses and posts of @UGADawg96 @fatBatman @Snakebitten @testerdahl among others

https://www.f150gen14.com/forum/threads/powerboost-changes-in-2024.24891/

https://www.f150gen14.com/forum/threads/2024-king-ranch-picked-up-from-granger-ford.23343/page-2

https://www.f150gen14.com/forum/search/6006770/?q=Bisg&c[users]=Snakebitten&o=date

https://pickuptrucktalk.com/2024/06/2024-ford-f-150-hybrid-engine-starter-dropped/

Now, here's my observation of two scenarios when ICE kicks back in while the truck is in motion:

1. I do not feel or hear anything except the increase of RPM, which is perfect/seamless. I suppose in this case, the hybrid motor starts the ICE.

2. I hear a "click" sound when ICE kicks back on, although I do not feel any vibration. The click sound is very similar to the traditional flywheel starter sound and it is noticeable and somewhat annoying due to the frequency of it in local driving.

Question: Does this mean that 2024 PB uses the traditional flywheel starter to start the ICE while in motion? Many 21-23 PB owners say the traditional flywheel starter sound is rarely heard because BISG and hybrid motor do most of the work? With the removal of BISG in 2024MY, does this mean the traditional flywheel starter is used more often?

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[UGADawg96]

I would think the flywheel would only be used from a cold start if there wasn't enough SOC for the HVB to start the truck in Electric mode. I cannot imagine the flywheel doing anything at speed. But I'm not an expert like @Snakebitten or @HammaMan or @Samson16

 

[Snakebitten]

My Factory Service Manual is for a 2022 Powerboost. So it included the BISG in various starting scenarios.
But the Bendix/flywheel starter was a coldstart/remote start method only. Or at least that's how it read.

I don't know what the annoying click you hear is, but I'd be surprised to hear that the 12V flywheel starter was in play. Certainly not while the vehicle is in motion.
But I also wouldn't be shocked to hear Ford removing the BISG caused them to use the flywheel starter at stops just like they do with ICE auto/stop-start?

I'd love to get my hands on a 2024 Factory Service Manual. Or login to PTS with a 2024 VIN and view that portion of the online service manual.

You can do that yourself for about $25 for 72 hours and scrape as much content as possible?

 

[DeepBlue]

My Factory Service Manual is for a 2022 Powerboost. So it included the BISG in various starting scenarios.
But the Bendix/flywheel starter was a coldstart/remote start method only. Or at least that's how it read.

I don't know what the annoying click you hear is, but I'd be surprised to hear that the 12V flywheel starter was in play. Certainly not while the vehicle is in motion.
But I also wouldn't be shocked to hear Ford removing the BISG caused them to use the flywheel starter at stops just like they do with ICE auto/stop-start?

I'd love to get my hands on a 2024 Factory Service Manual. Or login to PTS with a 2024 VIN and view that portion of the online service manual.

You can do that yourself for about $25 for 72 hours and scrape as much content as possible?

May I ask where to find the Factory Service Manual? I see Helm and Factory-Manuals both offer a service manual? Also, Ford Service Info has this 72hr subscription for $26.34.

 

[HammaMan]

Question: Does this mean that 2024 PB uses the traditional flywheel starter to start the ICE while in motion? Many 21-23 PB owners say the traditional flywheel starter sound is rarely heard because BISG and hybrid motor do most of the work? With the removal of BISG in 2024MY, does this mean the traditional flywheel starter is used more often?

Interesting. I've speculated things w/ gen 1 PBs and have yet to fully test them (need a handful of variables w/ forscan logging). If the truck is stopped, the HVB fires the ICE 99% of the time. Our flywheel starter is pretty much never used (I've heard mine twice, it's noticeable) . I'd been curious about how the in-motion starts are happening in 24s and if you're hearing the starter then we have our answer. There's more than one rolling start condition though, there's at speed and power demanded. Keep in mind the ICE to traction motor clutch is essentially a wet transmission clutch like any other but it's in a much different spot. The stator of the electric motor and the flywheel are bolted together. The clutch sits between them and the ICE.

I theorized perhaps they nailed unlocking the torque converter and clutching in the ICE which can be hard to do At the same time I could see them just using the starter that's already made for a start/stop duty cycle. Anyone that's push-started a 5/6 speed knows the feeling. Same with shutting off the engine at speed and then clutching it back alive. It's not that it can't be done, it's making that transition unnoticeable, that's the trick. Perhaps the bean counters said it saves beans, who cares if they hear it? With gen 1 PB, when you're rolling you cannot hear/feel the ICE come back at all. It just slips in and out without a peep or a shudder.

A sudden acceleration command can change that though as it pretty much will start / downshift / clutch in the ICE all at the same time. Hard to make that pretty.

 

[Snakebitten]

May I ask where to find the Factory Service Manual? I see Helm and Factory-Manuals both offer a service manual? Also, Ford Service Info has this 72hr subscription for $26.34.

I have the factory-manuals version purchased using your VIN. It will be an ~18,000 page PDF.

 

[dochawk]

I hate to ask how much that pdf cost. Surely more than the $35 or so I pay on my old Cadillacs . . .

[and hopefully more sanely indexed and paginated! One might even hope for working hyperlinks . . .]

 

[Gros Ventre]

In the Powerboosts before the BISG deletion, there is an over-running clutch between the engine and the electric motor. Thus the engine can drive the motor and transmission but not the other way around. There is no reason the motor cannot start the engine (it does in the Escape Hybrids), but for some reason Ford went a different way on the F-150s.

 

[HammaMan]

I have the factory-manuals version purchased using your VIN. It will be an ~18,000 page PDF.

Just pulled the info on a 24PB -- its manual is revised in 2020 and still shows the Belt starter

 

[Snakebitten]

Not shocking.
Those poor authors are probably at the end of the line for some things, like revisions in manufacturing.

 

[js312]

My Factory Service Manual is for a 2022 Powerboost. So it included the BISG in various starting scenarios.
But the Bendix/flywheel starter was a coldstart/remote start method only. Or at least that's how it read.

I don't know what the annoying click you hear is, but I'd be surprised to hear that the 12V flywheel starter was in play. Certainly not while the vehicle is in motion.
But I also wouldn't be shocked to hear Ford removing the BISG caused them to use the flywheel starter at stops just like they do with ICE auto/stop-start?

I'd love to get my hands on a 2024 Factory Service Manual. Or login to PTS with a 2024 VIN and view that portion of the online service manual.

You can do that yourself for about $25 for 72 hours and scrape as much content as possible?

In 17000 miles, I have never heard my truck use the conventional starter. It is possible it has with remote start on cold days occasionally and I just haven't heard it from inside the house, but I have never personally witnessed it. It has to be rare.

 

[DeepBlue]

check out this driving POV:


If I am not mistaken, around 12:57, you can clearly hear the starter sound.
At a few other occasions, for example, around 11:34 and 11:48 the ICE kicks back in without such a sound.

Still puzzled how the logic behind starting the ICE works.

 

[HammaMan]

Yeah, that was the flywheel starter for sure

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