Simple Cheap Hybrid Car? (DIY)

[pete c]

I think Ryland's suggestion will probably work best for you. It does eliminate the ability to run on electric only in stop and go heavy traffic, but, it is far simpler, mechanically speaking.

I think a fairly high voltage motor/generator/starter mounted where the alternator currently lives could work. Being an electronics type, you should be able to come up with some sort of engine stop/start system which would maximize city mileage.

You should also be able to regulate whatever voltage you use down to 12 vdc to handle the rest of the car's needs.

Good luck with it, Chris. Show us that an englishman can actually make a functional auto electric system (insert obligatory Lucas joke here).

[chrisoverson]

Originally Posted by pete c

Good luck with it, Chris. Show us that an englishman can actually make a functional auto electric system (insert obligatory Lucas joke here).

lmao .

Well my car was designed and built in England so that's a start.

The car is a 1998 Rover 218 iS weighing 1032kg, 1.8 litre naturally aspirated K-Series engine, Aluminium head and block with Twin Overhead Cams.

Manual gearbox with 5 forward gears and one reverse gear so pretty standard. 4 spark plugs, multipoint fuel injection controlled by the Rover MEMS1.9 engine management system, which is OBDI.

The car has power asisted steering (belt driven), alternator belt driven obviously, DC fan which hardly ever kicks in, and no air conditioning, although there is an air-con version of it.

Standard highway rating: 48.4mpg, city rating: 27mpg. My current best is 57.8mpg with an average speed of around 34mph.

Drag coefficient: 0.330cd
Frontal Area: 2.00 square metres
Cda: 0.66

Current gearing puts the engine speed at 55mph in 5th at 2488rpm

Here's the car:





Engine bay:





My cone air filter:





My grille block test:



Here's my DIY arduino based fuel monitor and MPG calculator:



Thanks all for the current ideas... I'm liking the mild hybrid idea best, the idea of a 5th wheel would be a little too rediculous looking for me. I want to preserve the looks of the car where possible as I have future design plans for it to modernise it a bit. If I was absolutely dedicated to MPG to the extent I'd make such huge alterations I'd just change cars to something more economical . Even if the other options are more complex... I'd rather go that way. I'm aiming for a more professional OEM outside appearance really.

So if I were to attach an electric motor to the the engine, I could easily mount it where the power steering goes... but would it be able to assist the engine and be belt driven? If so, I'd be interested in this idea as I was thinking of converting the power steering to an electrical pump anyway as I could turn it on/off as I wanted.

[pete c]

I have a better idea for an energy source for steering.

It's called arm assist. They used to use it on vehicles much larger than yours, back when men were men.

The auto industry seems to have convinced us all that we need power assist for braking and steering. It certainly is nice in an S class benz, but, IMO it is a waste of money in a 2000 lb compact.

So, convert it over to powerful steering or I will have to taunt you with nancy boy jokes!

I suppose maintaining vacuum assist for braking is OK as it is basically free power and will allow you to conserve energy for those parking lot steering workouts. Also, I assume you may have some sort of ABS which probably needs to have the vac. assist to function properly.

Personally, I wish I could buy a modern subcompact with absolutely no power assist like I had in my '78 fiesta. I think such models exist for you euros, but not for us obese lazy colonists.

[chrisoverson]

Originally Posted by pete c

I have a better idea for an energy source for steering.

It's called arm assist. They used to use it on vehicles much larger than yours, back when men were men.

The auto industry seems to have convinced us all that we need power assist for braking and steering. It certainly is nice in an S class benz, but, IMO it is a waste of money in a 2000 lb compact.

So, convert it over to powerful steering or I will have to taunt you with nancy boy jokes!

I suppose maintaining vacuum assist for braking is OK as it is basically free power and will allow you to conserve energy for those parking lot steering workouts. Also, I assume you may have some sort of ABS which probably needs to have the vac. assist to function properly.

Personally, I wish I could buy a modern subcompact with absolutely no power assist like I had in my '78 fiesta. I think such models exist for you euros, but not for us obese lazy colonists.

lol fair enough .

I used to have no power steering on my first car, a Peugeot 106 1.5 diesel. I imagine the efficiency on that was pretty good and I've thought about getting another one but the ride and comfort was shocking, along with the build quality.

I can drive my car without power steering, and I would hapily sacrifice it for fuel economy, but if it only gives me something rediculous like 1mpg then I'd rather keep it as it does get bloody heavy and 90% of my driving is in town.

[pete c]

It's bloody heavy because you are having to manually drag all that power assist stuff around. I could do the same with my old 91 accord. I can not do it with my ranger or my wife's sonata. Parking lot steering with them most definitely requires assist.

Is power steering an option with your car? If it is, you might be able to find a manual steering rack. Or you could just step up to the challenge and enjoy the popeye like forearms that you will soon develop.

[chrisoverson]

Originally Posted by pete c

It's bloody heavy because you are having to manually drag all that power assist stuff around. I could do the same with my old 91 accord. I can not do it with my ranger or my wife's sonata. Parking lot steering with them most definitely requires assist.

Is power steering an option with your car? If it is, you might be able to find a manual steering rack. Or you could just step up to the challenge and enjoy the popeye like forearms that you will soon develop.

xD no it comes as standard on all of them. To be honest I prefer the idea of electric power steering that I can turn on or off as I need it. In the mean time if I can't find such a pump I'm happy to go without and make like popeye .

So, back to the original point, could I put on a motor in place of the power steering? If so would the belt be able to transfer enough energy to the engine to make a positive difference...

[nimblemotors]

Originally Posted by chrisoverson

So, back to the original point, could I put on a motor in place of the power steering? If so would the belt be able to transfer enough energy to the engine to make a positive difference...

A key to the mild hybrid idea is to replace the starter and alternator with a single motor-generator that can assist the engine. It adds no additional weight and is a simpler design. Strange it still isn't common even today.
What it allows is to tune the engine to have less low-RPM torque.

If you just ADD the weight of the motor, and don't retune the engine to take full advantage of the electric power, I don't think the gains will be much, since even the tuned versions it isn't that big.
For stop-n-go, a Prius can yeild large improvement because the engine isn't running at all, and braking can put back the power used. You get none of that with the mild hybrid and certainly not the add-on approach.
Swap your car with a Prius, it requires no work or mechanical skill at all and you get 50mpg, and not only does it look oem, it IS oem.
You will not be able to do yourself anything better and cheaper, without changing cars and/or engines.

[chrisoverson]

Originally Posted by nimblemotors

A key to the mild hybrid idea is to replace the starter and alternator with a single motor-generator that can assist the engine. It adds no additional weight and is a simpler design. Strange it still isn't common even today.
What it allows is to tune the engine to have less low-RPM torque.

If you just ADD the weight of the motor, and don't retune the engine to take full advantage of the electric power, I don't think the gains will be much, since even the tuned versions it isn't that big.
For stop-n-go, a Prius can yeild large improvement because the engine isn't running at all, and braking can put back the power used. You get none of that with the mild hybrid and certainly not the add-on approach.
Swap your car with a Prius, it requires no work or mechanical skill at all and you get 50mpg, and not only does it look oem, it IS oem.
You will not be able to do yourself anything better and cheaper, without changing cars and/or engines.

Ok so what you're saying is the mild hybrid idea is doable on my car but I won't see gains without tuning the engine properly, and any gains I see will still be less than having a hybrid car anyway.

Well I don't really want to just switch to a Toyota Prius just yet... as unless it can offer me a huge improvement (and 50mpg isn't really) then it won't pay for itself with the number of miles I do, as I don't do many long distance trips.

How would the mild hybrid system work then? Do I simply attach the motor in place of the alternator or power steering and make it spin the driveshaft at the same RPM the engine is at? Or differently...

The engine management side I can do, as I'm very familiar with how the engine management works and I'm planning on converting it to megasquirt so I can remap it.

[nimblemotors]

I suggest the prius because seeing your car, it isn't a clapped out metro or such, it is a car that is similiar in value to a Prius. I know their prices have gone back up again, have you priced one lately? I bought one of mine for $3,000, the second for $1500, and the third for $1,000. All had something wrong of course, but easily fixed, easier than adding a hybrid system to an existing car! And btw, I have built a dual-powered hybrid, by adding an electric motor to the rear wheel of a Ford Aspire (sorry can't find the pics easily), it was a LOT of work. But it did allow all-electric driving of the car, no gas at all for local driving.

[chrisoverson]

Originally Posted by nimblemotors

I suggest the prius because seeing your car, it isn't a clapped out metro or such, it is a car that is similiar in value to a Prius. I know their prices have gone back up again, have you priced one lately? I bought one of mine for $3,000, the second for $1500, and the third for $1,000. All had something wrong of course, but easily fixed, easier than adding a hybrid system to an existing car! And btw, I have built a dual-powered hybrid, by adding an electric motor to the rear wheel of a Ford Aspire (sorry can't find the pics easily), it was a LOT of work. But it did allow all-electric driving of the car, no gas at all for local driving.

Thanks for the idea

Well I'm actually holding out on the idea of switching cars because my uncle has offered me his Honda Civic hybrid for £900 when he comes to sell it. That could be a fair while away though...

Hybrid cars are not very common over here, certainly not for that money. Also my car is not worth as much unfortunately, if I were to sell it I might get perhaps £500 for it but not really much more... I like the idea of using it as my project car even if it costs me because I love the cars and know them inside and out, having had 3 of them. (2 diesels and this petrol).

I can get 57mpg out of my car now, which is not all that bad. If I could see 65-70 out of it I'd probably be happy, so this is my goal.

None of the smaller engines (there's 1.1, 1.4, 1.6 and 1.8 versions) offer much higher efficiency, only Rover's VVC engine which is a little like a honda vtec, offering variable valve control. Even if I fitted this I wouldn't see a huge improvement as the book states mine at 48.4mpg, and the VVC version is around 49.3.

Currently I'm wanting to try aerodynamic changes, hot air intake, higher tyre pressures and power steering delete. I'd really love to try the electric assist idea as even if it just makes a little difference it would be worth testing .