Never gonna happen dream tdi diesel hybrid

[bandit86]

01 beetle diesel, 5 speed. I had over 50 mpg tanks, but typically it is 43.5 to 44 @ average speed of 76mph. Mostly highway, can't slow down or it's gonna be more hours behind the wheel.

Even hybrids don't like sustained high speeds. But what I was thinking you guys might like and appreciate, is that the rear wheel can be converted to AWD, but what I want is either an electric motor connected to just one wheel or an even smaller diesel like a Kubota 2cyl direct drive with a clutch... Since I only need to maintain highway speed I only need about 12 horsepower.

[freebeard]

Speaking of never gonna happen, I've got a Lexus electric axle (98lb 68HP) that needs batteries and VFD controller.

I'd give Ecomodder discount pricing, as is where is.

[oil pan 4]

12hp is pretty optimistic. My Nissan leaf needs up to 25hp to maintain speed in a head wind during the winter.

[cRiPpLe_rOoStEr]

Originally Posted by bandit86

what I want is either an electric motor connected to just one wheel or an even smaller diesel like a Kubota 2cyl direct drive with a clutch

The electric motor seems to be easier to control than a Kubota Diesel operating at a fixed speed. Anyway, most likely the added weight of an engine which may eventually have a lower efficiency won't be worth at all.

[Logic]

There are plenty of electric rear axles and controllers on the net.
But lets say you find a worthwhile on that operated in your speed range; how do you get the rear wheels to turn at the same rpm as the front ones?

Simple: (well simpler )
E-bikes use a torque sensor in the crank that senses how much effort you are putting into pedaling.
You then dial in the amount of assistance you'd like on the controller.

So all one would need is similar torque sensors on the front axles and you're good to go with a fully automated system that would feel just like a more powerful, or more economical engine, depending on your mood.
It has regen too.

You would then have 3 modes:
Petrol: front.
Electric: rear.
Both: thx to the torque sensors.

There are a couple of very clever and industrious people on Endless Sphere that can help with the electronics.
The kind that build motors and controllers.
Some financial incentive would likely help though.

[Piotrsko]

bldc controllers can provide tach style rpm signal data either as a frequency or voltage or, wait for it: digital signal. Some can tell you how much power is being requested, some how much applied, or both but it's an easy sample on one pair of motor leads. Automotive controllers have all sorts of data on the OBD data bus indicating stuff you never care about if you can decipher it.

[Logic]

Originally Posted by Piotrsko

bldc controllers can provide tach style rpm signal data either as a frequency or voltage or, wait for it: digital signal. Some can tell you how much power is being requested, some how much applied, or both but it's an easy sample on one pair of motor leads. Automotive controllers have all sorts of data on the OBD data bus indicating stuff you never care about if you can decipher it.

Ah! thx Piotrsko.
The more electronic side of things is above my pay-grade as I've never dug into it.

NB that here you'd have a stock FWD car.
So while a real time digital rpm and power signal is likely available somewhere in/from the car's electronics, and translatable, I'd rather leave all the stock electronics well alone.
I go under the assumption that most other's think similarly.

Wheel speed is easy but:
Where would one go looking for said power signals if, like you, we knew what we were doing?

[cRiPpLe_rOoStEr]

Originally Posted by Logic

You would then have 3 modes:
Petrol: front.
Electric: rear.
Both: thx to the torque sensors.

Peugeot and Citroën have a similar setup for some of its hybrids

[Logic]

Originally Posted by cRiPpLe_rOoStEr

Peugeot and Citroën have a similar setup for some of its hybrids

Sure, but Peugeot and Citroën have insider info on where to get and translate wheel rpm and torque data so they can match the wheel rpm and be clever about the amount of torque supplied.

If you don't have access to that real time insider info; how would you implement an electric rear axle in your garage..? For any car..?

Finding the wheel speed sensor wires is easy enough. Now translate that data into something you can use..?

[cRiPpLe_rOoStEr]

I didn't say it would be easy to make a similar setup at home. But anyway, since wheel speed sensors of the ABS brakes seem to provide input to electronic traction and stability controls, maybe they could provide a similar feedback for torque vectoring on an auxiliary electric drive.