How The Easiest Hybrid Diy Could Be Done...
 

I SAY (not an expert :) )

Simply put a 10hp (ala insight) engine connected to a fifth wheel, an on and off switch, and directly hooked up to the battery.

How would it work?
Go 60-65mph, turn electric engine on, stop pressing the gas pedal as much (close to idle, but just enough to slightly adjust the speed) and vuala! The alternator supplies the energy needed for the engine to run...

That way, instead of going 2500+rpms you would be going 1000-1200rpms and saving gas.

??

Or am I thinking WAY to simple here? I KNOW SOMEONE has had to try this, did it work or did it not and why?

you need X horsepower to maintain speed. you can either drive the wheels with the engine at that HP or you can convert rotational force into electrical and back into electrical. and lose some to inefficiency in the process...especially at 12v.

problem 2: most hybrids run off 240-350v 3-phase AC power...not what's coming out of the alternator. 12vDC motors are much less efficient. a 10hp 3-phase electric motor is pretty big (150-200lbs) and most hybrids integrate it into the drivetrain in a non-transferrable way.

BTW an electric motor is not an engine. I assume you mean use the insight electric motor.

True...

Or even simpler, get a 10hp diesel engine (on eBay for about $400) and connect that to a wheel. You could even use it in stop and go traffic and even completley turn off the big engine in your car... ? Easier and cheaper than electric.

If you could find a 12 volt electric motor large enough to work, it would work... for about 10 minutes if you are lucky, at that pont your battery will be dead, your wires will be melted, and such a large load will be put on your alternator that if you don't blow the fuse, it will simply lock it up, and start burning up the belt that drives it.

Not exactly the same method of execution but Mike D. did more or less the same thing with his Insight

https://99mpg.com/TheBestHybridmix/

I would just put an engine in there with a throttle control in the cab/front of car. a gas/diesel engine in the trunk so you could just shut the engine off completely when you got up to cruising speed. you could just pop the clutch when you needed a little more oomph from the big engine. you would also have to make some way of routing the exhaust out of the car. then a bar with a wheel and a belt going to the wheel and the bar would be mounted on a pivot with a spring for flexibility. this is, after you have cut a big-ish hole in the floor of your trunk/truck bed. you could seal it with a nylon brush on either side. there would have to be a pretty big pulley on the engine, to make the wheel go fast enough for 50-60 mph.

I agree this is a good idea and it's even better if you can make a boom that goes out behind the car so you don't have to cut a hole. maybe it goes over the lift gate (in a truck) then there are two pulleys attached to each other and two separate belts.

what do you think guys?

^^^ Exactly...

The problem is the gear reduction, if the shaft is (lets say) about 1/4" and spins at a max of 3,500rpm's what size of reduction gears would you need to get it right at 60mph? (to use it in the highway).

Or you could probably also mate it to a small motorcycle transmission or something simillar so you could use it at low and high speeds?

If you did this to a Civic VX or similar, I bet you could easily net around 80mpg in highway... ?

Dangerous much?

Engineering nightmare much?

Optimistic much?

I really don't think its safe practice to be placing ANYTHING inside the driver compartment that is rotating at 3,500 RPM... or even 10 rpm.

for the sake of contribution...

why not take a motor (you choose AC or DC) supply w/ the proper power, and customize your drive wheel/wheels (2 motors for CV) by mounting up some type of gear inside of the wheel, maybe like a round track w/ teeth, then use a switch to turn the motor on/off to help rotate those wheels forward. If it took 20% load off the engine, it would help somewhat. I have enough spare motors at work I bet I could make this happen... although I'm doubtful because most of the motors I have are the correct size, and yet, only 1/2 or 1/3 HP. I do however, have a 7 HP spare motor for my air compressor, and its practical to mount a gear on the end of the shaft and then do the above to the drive wheels... supply power and a switch.... it would work... much easier this way I think.

Keep in mind, I haven't thought that out at all.

On second hand, I bet you could make a really fun go-kart using the method above.

you wouldn't have to have anything spinning in the drivers compartment if you had it all in the trunk. quieter too.

yes of course it would be quieter to use electric, but then you wouldn't be getting the most possible mpg, because you convert the torque into electricity then back to torque. at 12 or even 24 volts it ain't too efficient.

If an 8 inch trailer tire was used as a spring loaded "5th wheel", it would need to turn 1200 rpm to give 60 mph. This would be a simple 3:1 engine to tire reduction. So, weld an 8 inch pulley to the trailer tire rim and use a 2.5 inch pulley on the motor (assuming 3600 rpm).

My math: tire diameter= about 16 inches. Circumference= about 50 inches. Inches per mile= 63,360 / 50 inches per revolution = 1267 revs per minute for 60 mph (1 mile per minute)

Electric-
Hmm, so you say they use a 10 hp 3 phase motor- I have two 7.5 hp 3 phase motors (240-480 volts) laying around. So assume the hardest part is making the box that transforms 12 V DC into 3 phase AC. And then there is the issue of hauling around 10 or so car batteries.

here's the math
watts=amps*volts
7.5 horsepower=5595 watts

for 240 volts
5595=a*240
23.31=Amperes
Because motors are NOT 100 percent efficient, we can say 25 amps respectively.

for 480 volts.
5595=a*480
11.65=amps
again, add a few amps respectively to get 13 or 14 amps.

So, it would be convenient if you had a 14 amp 480 volt generator or a 25 amp 240 volt generator that just happened to fit the alternator spot.
then you could use some kind of a converter to charge the battery in place of the alternator.

the problem with this is that the engine won't be running at peak efficiency (about 2-3 Krpm) and if it were then I think it would be making more than 15 horsepower.
that is why I think it is a better idea to use a smaller engine rather than go electric.

just a cool little thing I found.
https://www.unitconversion.org/unit_c.../power-ex.html

I see what you mean about the gasoline generator being inefficient- I was thinking a "plug in" electric drive that could be used around town and save the ICE power train for high speeds.

are those motors you have ac or dc?
it would be much easier to use dc because then there isn't any inverter/separate generator to deal with.
but you would still have to have 20 deep cycle batteries and isolator circuits to charge them all off of low voltage.

thecheese- they are AC (3 phase). I just mentioned them because kamesama pointed out that hybrids typically use 340-580 volts to power a 3 phase 10 hp motor

I'm not serious about doing a conversion (yet). But I'd be willing to cheer someone on who has the time and $ to do it- and if they were successful with using a similar 3 phase motor, then I might give it a try. Yeah, yeah, call me a chicken, because its true in this case:)

clencher- do you know of any 5th wheel/trailer success stories? Or did they all turn out "just as good as stock ICE"

A worry of mine would be that if a converted vehicle was in an accident- the lawyers might try to use that to get some $$$ or to place blame even if the mods had nothing to do with the accident.

My insurance company always asks this question when I get coverage on another vehicle: "Has the vehicle been modified in any way?" This is part of the insurance policy "application".

Maybe I'm on a one track mind or something, but I keep seeing how much easier it would be to put in a diesel or gas ice in the trunk. the smaller the engine, the less fuel used. the closer to peak power, the better the efficiency. with the main ICE under the hood, you would be using all of the cylinders rather than one or two of a small engine. you also have to deal with the fact that you are using fuel to open the valves when you are at idle, where you would be using this. I guess that what I'm thinking of is extreme P&G going entire street blocks at a time till stopped by a light.
A .5 litre two cylinder engine is more efficient than a 1.5 L 4 cylinder at idle.
maybe even using the smaller ICE to run a generator and then a motor of some kind.
Am I alone on these thoughts?

I would think it would help city mileage better than highway...

First you want to find a light diesel engine . . . good luck!
Battery power - forget about running on the highway on electric - the Prius can't even do that unless it is down hill - you just don't have a big enough battery to provide enough power - only maybe at 30 mph speeds on level roads it could work which is ok because that is when the ICE is wasting a lot of fuel and not putting out a lot of power. Beef up the alternator with a high output 3 phase generator on the main engine that can output high enough voltage to charge a second higher voltage battery and run an electric drive and you can operate the ICE under low rpm higer load more efficient operation and maybe if you keep the losses low enough you could come out ahead. You still have the issue of the battery life. It all comes back to making the gas burn better in the stock motor as the most cost effective solution. Remember that even a small engine is going to convert fuel at the same or less efficiency as a big engine - about 25% so you can't gain much that way. As a case in point the TaTa car is still only getting 50mpg which is what the Geo would get with a 3 cylinder 1 liter engine.
If you really want to save some gas and have some fun then build a new vehicle with two or three wheels, electric powered and get away from the extra weight and complexity of a gas vehicle.

How about compressed air?

Electric air compressor, also connected to one rear wheel for regenerative(compressive?) braking, a compressed-air tank, and a simple piston/cylinder/valve setup hooked to the other rear wheel. Then you'd just need a mercury switch to turn the regen on when the car's downhill, and a brake pedal switch to turn it on for regenerative braking.

Plug in the compressor at night, regenerative braking to keep the air cylinder pressurized etc, an extra boost on starts or when needed, should be very light and simple to engineer.

Whaddya think?

Mike in CT built one.

OK, he built it into a Honda Insight so he already had a big battery pack installed. Might have increased that to support the 5th wheel. But you have to admit his site is an interesting read.

His home page: https://www.99mpg.com/

https://www.99mpg.com/5th_wheel_in_place_trial_1.jpg,0

Not the easiest homemade hybrid but one of the nicest I have seen!

https://www.homepower.com/article/?file=HP97_pg98_Scott