Generator attached to the flywheel instead of the starter motor, and then find some way to squeeze a drive motor by the rear diff (probably more complicated, but surely not impossible). I thought something might pop up once companies like Bosch started making generic e-axles for manufacturers to use.
With a small Li-ion battery (and all the usual inverters, etc.), it could work like a manually operated version of the dual-motor Honda hybrid system. Put it into neutral, and whatever energy is in the battery could drive the motor on the rear axle. The engine could automatically kick-in and drive the generator if there's not enough in the battery.
It would never be as economical as a purpose-built hybrid, but old manual cars are often reasonably economical on the open road, and terrible in city traffic. Targeting only the urban fuel consumption would go a long way towards keeping them useable, with the added bonus of making manual shifting optional in stop-go traffic. Small motors would be enough for city speeds, and with a small battery, it sounds cheap to me at least.
I doubt it could ever be a simple kit, but I thought people would have a go.
Looks like he did commercialise it: https://www.jauntmotors.com/series
I recognise some of the photos from back then.
Some vehicles have this as a “battery starter generator” where the “hybrid” functionality is entirely on the accessory belt.
https://www.bosch.com/stories/48v-hybrid-battery/
https://hackaday.com/2025/01/24/bosch-starter-motor-freed-fr...
The best time to run your a/c or turn the seat warmers: when you’re trying to expel energy.
Would give you some extra braking without heating up the engine and take a small load off your brakes.
That or turn any vehicle into a mild plug-in hybrid for all electrical loads and flywheel the alternator until that time. Gasoline-powered generators are not very efficient.
Might get a few percent extra efficiency without having to touch anything mechanical.
That would effectively add 4wd to old cars and allow the onboard engine to work normally with an option for eboost/edrive with the only extreme modification being adding the battery and control modules.
I've considered it as a modification for FWD track performance cars. It is much easier to add a hub into a stiff rear axle. Turns out, that adding an electric motor, which is not part of the main engine assembly, ads way too much complexity in controlling the whole thing and weight to power ratio, that it stops quickly stops making sense.
1) New cars are too cheap to make at scale.
2) Old cars are quite unsafe to drive, comparatively (airbags, backup cameras, lane departure alerts, blind angle alerts, etc)
But yea, as for the rest of the "safety mechanisms" the only modern change that I can think of that's not easy to retrofit but is a huge safety boost is blind spot detection. As someone that drives older (and smaller) cars, being able to see the blind spot detection light on other cars' mirrors is always a bit of a relief that their car will notify them if they try to change lanes.
I think there are important dimensions of safety that go unmeasured. You have much less road awareness in new cars.
Survivability is great and all, but not at the expense of children and pets becoming invisible.
All the focus on survivability provided another incentive for makers to put ever larger pieces of steel on the road. I disagree that new cars are safer.
I have experienced driver aids glitching, and i want none of it. Anything that can take control of the car needs to be bulletproof, and it isn't.
It should be possible to just replace the flywheel altogether with a generator/motor that both brakes and powers during each cycle, cancelling vibrations. Then more generation during deceleration, and more power during acceleration.
We just read a story of someone who didn’t want to pay market price and went DIY.
There are companies doing bowling alley equipment and you can pay them for maintenance.
Is there a single one of those on F500 list? No and people are running those companies and what OP did … he didn’t want to pay market price.
Well yeah those companies are overpriced if you are software engineer who can wire up and program couple of ESPs have own bowling alley and have free time.
I'm tinkering with an auto-provisioning function that tells a given ESP what node type it's connected to and configures itself from there.
I’ve had similar experiences with “enterprise”-grade hardware.
But sometimes the “price” isn’t just the hardware, but also having someone on-call 24/7 to support and possibly fly-out to investigate within X hours.
It's really easy to pull $300k/y as an SRE (but that does amount to about $100/hr equivalent in SMB, assuming realistic >40h workweeks and the tax advantages in SMB, even less if you have to pay for services you enjoy and can't find time for due to FTE - nannies or even changing your own oil).
It is extremely hard to keep that $100/hr and a sliding scale - one week you work 50h, the other 30h, then you take a month or three off at $5h/week.
Mine (and I don't regret these) is running midsize PV plants. Slightly bigger than residential (hey, does OP want solar PV on the rooftop? I have a bowling alley as a client, they are a great match), but again not large enough to attract a scaled business.
I approximately put in 5h on each a year after the initial setup (around 100hr each), for $10k/y in profit from each.