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Building A Diesel Electric Hybrid Conversion Kit

70384 Views 33 Replies 14 Participants Last post by  26it073
Hello all.

This is my first post to this forum so please excuse this post if it happens to be in the wrong section. I am currently in the design and early building phase of a Diesel Electric Hybrid conversion kit for cars and trucks and I am looking to see what kind of market is out here for this kind of product. I have very customized parts that will enable me to compete and beat many true EV conversion kits (I know, blasphemy).

Diesel engine is going to be a twin cylinder, water cooled, turbo charged, intercooled, 0.8L diesel engine. The engine already meets EPA Tier IV specs. Max rpm is 3600. The engine is further enhanced by several scientific technologies (like engine coatings, ect...). Looking at 50 miles per gallon minimum fuel efficiency. Other technology is being created to increase this above 60 miles per gallon.

Generator will be 12kw to 15kw and will produce all power required to cruise a vehicle at 90 MPH at rated fuel efficiency.

Using a permanent magnet motor, 3 phase, 120V AC drive assembly with an IVT (already in negotiations with company for rights). Total electric motor power will be 20KW nominal, 40KW Max. Also going to integrate the gear train into the electric motor for an IVT gear motor, though this is in the advanced stages of the kit. Also considering a Warp11 with Solitron controller.

Battery pack is small, 4KWH, and only used for acceleration of the vehicle. Considering ultracapacitors, but they seem expensive when you consider the load balancing and charging electronics needed. Regen breaking captures braking energy.

As I build the prototype, I will update this post with pictures. My first conversion is going to be a 1997 Mitsubishi Eclipse, converted to a RWD via the GSX rear end. I blew the engine and decided it was time to follow my dream.

I look forward to your comments and suggestions if you have any. You can follow me through my website as well if you so choose;

Thanks in advance,

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I chose diesel because for many reasons. First, it doesn't have the throttling losses a gasoline engine does as speed is controlled via fuel input, vice air input. Second, is the way the fuel is delivered (direct injection is more effiecient and make better power/torque). Third, a person could run bio diesel or straight vegetable oil (like waste oil from resturants). Diesels are more efficient than a gasoline engine due to the burn characteristics of diesel allowing higher compression with a longer stroke.

The expected cost for a conversion kit should be around $8,000. I have good relationships set up with the electric motor supplier and the diesel engine supplier. My target price will be set to compete directly with EV kits. A 20KW (40KW Peak) engine for this kit for instance costs me about $1500 and runs around 90% efficient at 120V. Motor controller costs $1000 and handles 600 Amps. Engine and generator will be about $3500 after upgrades. Batteries for the kit cost $1200. Extra's add the additional 800. Looking at selling them for $9-10k. That should be a couple thousand cheaper than an EV conversion based on my calcs and provide a useful range of well over 500 miles per 10 gallons of diesel.

I love EVs. The issue just seems to be with the range. It is limited. Batteries just don't have the energy density that liquid fuels have. Until we go to more of an electrolyte/fuel cell model of fuel distribution, I think fossil fuels/algae/vegie oil is here to stay.
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You are right. I should have said motor vice engine. I won't make that mistake again, especially in this crowd.

I get the sense that this might be a worn out topic. Thanks for any help you all can provide. I will post my results here as I get them. I will be making videos of the entire process. It's kinda exciting to be honest. If anyone wants to help, I would gladly accept it. I am in Portsmouth, VA.

Thanks again,


thanks for the info. I have never seen this site before but that is the method of hybrid motoring I am working on building. Their pricing is extremely high though, pushing 80k. They use a fixed gear box attached to the electric motor which appears to be a fixed ratio, vice a traditional transmission. While a direct drive system provides excellent torque, it does require massive energy to power it instead of using a gear set to amplify torque.


Thanks for your input. These figures were based on some EVs I used as test vehicles in order to get some "real world" data. Current draw at 90 mph at 120 volts with radio, ac, and lights was just under 120 amps. This was with regular lead batteries in a Mitsubishi Eclipse EV. Electric motor was attached to a manual transmission (and an IVT once the owner and I reach a license agreement). If you have different data, I certainly welcome it. 40kw is a lot of power, roughly 50 hp. I know that running a car at 90 mph takes some power, but 50 hp sounds high. Based on my calculations, it would take about 31 hp to travel at 40.2 m/s (90 mph). 31 hp is equal to 23KW. I actually believe this might be a little high, but I may be wrong. I plan on using 15kw generator on the engine for a safety margin against these issues.

My diesel engine has plenty of power available (pushing 35 hp at 3600 rpm). I overpowered the diesel engine compared to the generator for just this reason. If my calcs are wrong, or the real world gets in the way, I can simply just adjust the gen size and compensate. If needed, I have a 3 cylinder turbocharged diesel that can put out over 50 HP, which is what I had planned on using for my F150 supercrew conversion. It is much heavier though so I would rather keep it for the truck.

I really appreciate your comments and welcome them all, good or bad. This will help me in the long run make a better product.
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The reason I am trying for 90 MPH at 50 MPG is I want to design a vehicle powertrain that is "Americanized". We all know, or I suspect we do, that Amercan's love performance and ease of use.

I know how I drive, roughly 75 MPH on most highways so I just want to make sure that it can handle that speed with that type of fuel economy. The EPA tests all cars on circle tracks at 55 MPH. IMHO, this is not really reasonable with most states having 60 MPH or better on their highways.


Thank you for your data. I will recalc my figures. What figures do you get for 50, 60, 70, and 80 MPH? Car will be on the road in May/June with just electric motors, batteries, and controller.

Anyone else care to chime in with their real world results?

Thanks again.

Thanks. We shall see the results soon enough.

Based on your calculations, my 40KW motors will not handle the requirements as set forth by you. I was looking at a 11" Netgain before I started working with the permanent magnet motors. I left the netgain due to no regen braking available. The permanent magnet motors I found do have the ability. Looks like I may just combine a few in series. What motor would you suggest to enable my vehicle to reach 90MPH?
Thanks for the comment. So here is the question I pose then:

What is the advantage of using a larger electric motor with 1 gear reduction (other than simplicity) vice a smaller electric motor and a transmission that is designed for an electric motor?

After much research and speaking with many companies about the one gear system, I have come to the conclusion that many set ups use the one gear system because there is a lack of transmissions designed for EV use. While this may be reality, it doesn't seem to be a good enough reason not to make the system better. While IVTs are new in use, though not new in theory and testing, it just seems to me that using this set up is better than running an electric motor through a one gear set at a speed that may not be in its optimum efficiency band.

My thought process was to build a system that gets rated gas mileage at higher speeds. Who wants to drive 60 mph on a highway that has a speed limit of 70 or 75? I am sure a few folks do just because that is the way it has always been done. It just seems easier to accomplish this with the ability to adjust the gearing system of the transmission to vehicle speed AND electric motor amperage requirements.

If I am way off on my thinking here, please calibrate.
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You can absolutely make bio diesel at home. While I agree that capturing sun and wind is available, it isn't viable on small scale at this point. Solar panels are only 20%ish efficient at best and way too expensive. I don't think batteries will ever be the future. I think super capacitors are the future, or fuel cells that exchange electrolytes.

Using the heat of the sun to make steam and turn a turbine is much better than solar panels IMHO. This can be done much cheaper than solar panels. A 7kw solar panel set runs 24k+ while a 12kw steam turbine/engine set up is only about 10k with the same or better efficiency.

I am still not sure why running direct drive is better. I just see adding an IVT between the wheels and motor just seems better to me. I guess it is a matter of opinion at this point. Instead of a IVT, maybe just a customized 2-3 speed transmission to amplify the torque characteristics of the motor. Somthing like the old 2 speed rear ends that some of the big trucks used to use. I just have a hard time imagining only having one speed reduction, when you can have multiple options, one for acceleration (0-20mph), one for city(20-45mph), one for highway(>45mph).

I have decided to use a traditional AC motor set up though. I am thinking the AC55 or AC30. Both seem to have great characteristics and are solid motors. I though that the 20KW BLDC set up would be nice as well, but the premise was on using a transmission and overpowering the motor to peak levels during acceleration.
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Please provide me the link to $1/watt solar panels for sale. I am ready to write a check. I have been considering solar panels for some time. Best price I have found is 24k, before batteries for energy storage for rainy days. At $1 a watt, I would start my own business installing them and selling the electricity back to the homeowner at market rates.

As for efficiency, it would depend on what type of system you use. Lets say for instance you use an ORC type set up. The heat transfer medium would be either R134A or R245. With the crit temp/pressure what they are, about 11% is the best efficiency you can get. Now, if you use a refigerant blend, it is very conceivable to get 25%+. Turbines are very efficient, pushing 75% in many cases, higher with a vacuum in the condenser.
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