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Welcome to the Electric Car Weblog. In addition to links, news, and tips about electric cars and other forms of alternative transportation we are publishing an on-line diary of our current EV project. Started in August 2005 the chronicle follows the conversion of a gas powered Ford Probe into an Electric Car.

You will find articles organized by categories, along with recent comments, along the right hand column of the website. If you are just getting started with the idea of converting a gas car to electric be sure to check out Your First Electric Car

Welcome and enjoy!

Lists of Lists · 5 December 05

Santa EV List

It’s that time of year.

Time to make lists.

We’ve had a few folks wondering what needs to be taken out of the old donor car, what to keep, and what “new stuff” goes into making an EV. I’ve posted partial lists elsewhere but never a full, comprehensive list.

Not that these lists will be comprehensive right off the bat. I’ll probably forget things and everyone’s EV will be slightly different.

The first list shows everything coming out of the donor car. How you remove this stuff is up to you: do it yourself, hire someone, or maybe the local High School shop class would be interested? In a perfect world we’d go to the local car dealer and order a “glider”, a brand new car without any of the gas engine stuff included.

Hey, we can dream…

Some of the parts might find use in the EV, if so I’ll put a yellow check next to the name. Green checks signify things you’ll probably be keeping. Even though you have no use for the other items you should still be careful while removing them. You never know what someone else might find valuable.

Instead of cutting wires off try to disconnect the connector and label the wire left behind with masking tape, if you can. You may never, ever need the wire but it’s far easier to get rid of it or put it out of the way if it says “engine heat sensor” than trying to discover what it is after the fact.

To remove:

R.I.P. First drain oil, anti-freeze…you’ll thank yourself later.
Radiator Fan
Nope. In fact you can probably close up most if not all of the front grill.
A/C & A/C Radiator EV Check
You can keep the Air Conditioning by hooking it to the main motor or even a separate electric motor. If so you’ll need the A/C radiator. Be careful unhooking compressor from engine and around the A/C hoses.
Gas Tank
Gone! Ditto with fuel pipes and pumps and sensors.
Heater Core EV Check
Located behind dash. You can buy an electric liquid heater option that hooks to this core and uses anti-freeze to transfer heat. Me, I go electric
Battery EV Check
A few EVs use only a DC-to-DC converter to provide the normal system 12vdc (lights, signals, meters, etc..), others opt for the battery and the DC-to-DC.
Alternator EV Check
I suppose you could rig up the old alternator to the DC motor instead of using a DC-to-DC converter.
Transmission EV Check
Unless you are springing for a custom gear box/AC drive then most likely you’ll keep the old tranny and adapt the DC motor to it. Most EVs use manual transmission because they don’t have to rig things up to keep the transmission hydraulics “pumped.”
Clutch EV Check
Yes, maybe, no? I don’t use a clutch, others swear by them. Depends on who’s driving the car, etc.. Unless you have regen the motor can’t be used to slow down the car (as you might do with a gas engine), so downshifting to slow down isn’t applicable. If you choose not to keep it then you can also get rid of the pedal and any cables/hydraulics.
Flywheel EV Check
I’ve never used them, but some EVs do. Helps keep a “load” on the motor, especially when shifting with the clutch.
Brakes/Master Cylinder EV Check
Yep, still need brakes. In fact without the gas engine to make vacuum you’ll need to install an electric vacuum pump and additional reservoir.
Muffler system
All of the pipes, catalytic, muffler, and those rubber-hangy things…gone!
Radiator Reservoirs
Not needed.
Wiper Fluid Reservoir EV Check
You’ll need this and the windshield drive motor of course.
Power Steering EV Check
This includes a pump and a whole bunch of pipes. We found that our first EV was easy enough to steer without any power assist. Maybe if you spend each day parallel parking you’ll disagree. To keep you’d have to rig up some sort of connection to the drive motor or use a separate motor.
None of this is useful for the EV, although some cars have a wire attached to the distributor for running the Tach. Keep this wire around, labelled, in case you decide to rig up a tach drive for the new motor.
Mount brackes EV Check
The old engine and transmission will have a bunch of brackets hooking them to the frame and chassis. Keep those, you’ll need to mount and brace the new DC motor and these may come in handy.
Heat panels
Your gas car puts out a LOT of heat, Summer and Winter. All of the heat shield panels, underneath and inside, can be removed.
Spare Tire EV Check
Depends on your commute. Some folks leave it at home to save weight and/or because they use the space for batteries. Carry a can of fix-a-flat instead?
To keep gas engines running these days requires one or more onboard computers. We don’t need no stinkin’ ‘puters!
Dummy Lights, gauges EV Check
If you are pulling apart the dash then some of the meters will no longer be needed (fuel, oil, heat) and some of the dummy lights can be removed out as well.
Air Intake/Cleaner
Not needed, what little air we might need for cooling the controller can come from anywhere (small fan).
The large cable, relays, and wiring just for turning the engine over aren’t needed.
Suspension EV Check
You’ll need all that and a bit more if you have a heavy set of batteries (and most of us do).
Factory Radio EV Check
In a world with iPods and XM radio? You can do better…
All depends on how crazy you want to be.

To add:

Electric Motor
DC typically (lower cost, wider availability) or AC if you have the money and source.
The controller translates your subtle foot commands (hey, go!) via a potbox into electric pulses that turn the motor. Type and cost of controller varies based on how much performance you want and DC vs. AC control.
As Lee Hart so deftly put it: Miles = BatteryType x Weight. For each mile of range, a particular EV might need 5 pounds of lead-acid batteries, 4 pounds of nicads, 3 pounds of nimh, or 2 pounds of lithiums. Pick your battery type, and you know how many pounds of them you need for a given range.
For filling the battery back up with worker electrons. Also a cord or plug to plug into a nearby wall socket.
Misc. Electronics
Relays, fuses, and wiring to hook the electronics up.
To help monitor and measure the system, notably the batteries.
Motor Adaptor
The motor needs to be hooked to the transmission.
Batteries need secure hold downs. If you aren’t in a warm place or the batteries are near a passenger compartment you’ll also need enclosures.
DC-to-DC Converter
Something to keep the car’s regular 12vdc system fully charged/happy. You could just use a battery and then recharge it each night with the larger pack (separate charger), depends on how much juice you need for lights, wipers, and blowers.
Comments 30
  1. — Greg Coleman    Dec 06, 2005 00:31 AM    #
    On the subject of clutches. How do most builders control the thrust from the clutch when it is pushed in? DC motors don’t have good enough bearings to control this do they? Shifting without one is so easy, I didn’t see a need for a clutch.
  2. Jesse    Dec 06, 2005 11:18 AM    #
    On the subject of spare tires: Definitely carry one. Fix-a-flat rarely works for even small punctures, and can’t fix a tire that’s come off the rim. Also, anybody who has to work on that tire after will want to murder you with dull shop tools, because when they pull the tire off the wheel, they get a shower of fix-a-flat.
  3. — James May    Dec 06, 2005 11:34 AM    #
    Greg. My car is an existing conversion. I think it has been about for 5 years. It has the standard clutch and flywheel. I am really surprised, but there seems to be no issue with bearings even wiht a standard clutch thrust and standard bulky flywheel. For Christmas I would like to have my flywheel lightened because I believe it’s wasting my power accelerating and decelerating it all the time – yuk! For a simple flywheel, (same thickness thru radially) the energy stored is proportional to radius to the power of 4. I wouldnt need to shave much off of the outside of my flywheel to make a lot of difference. There’s no need for the starter ring and there’s plenty of metal outside the clutch mating face.
  4. Jerry Halstead    Dec 06, 2005 19:29 PM    #
    Here’s a couple links for you James, you may have seen them earlier:

    flywheel machining

    remove ring gear

    Ease of doing this depends on the type of flywheel and/or you have access to a machine shope.
  5. — Dan    Dec 06, 2005 21:15 PM    #
    If the torch-hammer method doesn’t get the ring gear off, try sawing or grinding partially through the ring gear and then split it with a cold chisel. Once broken, the ring will come right off.
  6. — James May    Dec 07, 2005 09:24 AM    #
    Thanks. After I take the ring off I’ll send the flywheel away and get the outer edge outside the clutch face removed.
  7. — Joe    Dec 07, 2005 10:39 AM    #
    Great website for Tire size Calculations.
  8. Jesse    Dec 07, 2005 14:28 PM    #
    How much rotating mass does a typical electric motor have? Without a clutch, if the motor is just freewheeling, I wonder if the synchros could deal with synchronizing both the motor and the intermediate shaft. In my gas cars, I often shift without using the clutch using rev-matching, but that might be hard to do with an electric motor, because of lack of audio feedback. Hmmm… I wonder about making some sort of control system to rev-match the motor to the next gear?
  9. Jerry Halstead    Dec 07, 2005 19:55 PM    #
    Joe, thanks for the url. I edited your comment to make it a hot link. Nice to see how the size/shape of the tire profile changes with each setting.

    Jesse, I don’t know off-hand. The motor is 9” diameter and 15” long. The spinning mass inside will be smaller, maybe 5-6” diameter and 12” long or less? Total weight is 140lbs, not sure what portion the spinning components comprise.

    The transmission still makes some sound and the tach or speedo are good indicators. I think with this motor the max rpm is 7,000 but I’d never want to get to close.
  10. — James May    Dec 08, 2005 09:04 AM    #
    Jesse. I used to do clutchless gearchanges a lot as well. It’s the downchanges that are difficult! Gotta press the accelerator and brake at the same time. I think that matching the speed and changing with synchros only is probably a job best with electronics. Now there’s a project for someone. Would you be up for it Jerry?
  11. Fredrik Runqvist    Dec 10, 2005 05:42 AM    #
    Read on the first page that you have gotten a lot of questions about putting solar panels on your car. However, I cant fint the answer. Will there be any solar panels?

    And BTW, isn’t the ford supposed to be some kind a soprts car? Then there should be some liteweight dorrs, hood and windows for racing that maybe could be used to get a lite car.

    /Fredrik from Sweden were gas costs 4.91 per gallon.
  12. Jerry    Dec 10, 2005 11:12 AM    #
    Hi Fredrik!

    No solar panels on my car. My opinion is that they are best installed on a non-mobile surface, like the roof of a house or a sun tracking mount.

    Solar panels on an EV add weight, reduce aerodynamics, and for the $$ spent you don’t get that much additional range.
  13. — JohnG    Dec 28, 2005 19:37 PM    #
    Clutchless shifting with s synchromesh type transmission (most, if not all automotive types) is a VERY bad idea. The synchros are made of soft material like brass, and they will not last long if the speed differentials are great. They are designed to handle a differential of less than 100 rpm, that is VERY difficult to attain.
  14. — quasi    Feb 23, 2006 02:57 AM    #

    Has anyone considered a semi-automatic gearbox ie a standard auto that has had it’s ability to auto-shift disabled? Would sort out gear shifting problems and also make it possible to shift into Park to stop your EV rolling away.

  15. — Terry    Dec 27, 2006 07:16 AM    #

    Well, on the subject of a ‘semi-automatic’ gear box…... Years ago, Mazda produced what they called a TQ box. Essentially, a manual gearbox with a torque converter from an auto stuck on the front. The idea was that you would shift gears manually, but you didn’t have a clutch to worry about when shifting or stopping in traffic. Although I never drove one myself, they were an option on the RX5 which I used to own. Word on the street was that they were like $50.00 from the importers because none of the japanees liked it and almost all of them were pulled out and replaced with standard auto’s. I used to be heavily into rotaries years back and although my RX5 was a manual, and with the motor work done to it, it chewed up and spat out many a suped up V8, I never needed to replace the gearbox. apparently the RX5 manual box was the ‘ultimate’ in ‘bullet-proof’ness. However many in the rotary club (that rotary car club, not the do gooders that build new hospital wings etc) blew gearboxes left right and centre so they often grabed these cheap QT boxes and thrashed them till they blew then dropped in another one.

    Anyway, to cut the story short, if your looking for a manual gearbox that will change without needing a clutch, it might be worth hunting around for one of those old TQ boxes.


  16. jerry Halstead    Dec 27, 2006 08:29 AM    #

    Thanks for the tip Terry. Does it go by any other name or part #? I found a few mentions of a tq box in some auto forums, but that’s about it.

  17. — Greg Fordyce    Feb 25, 2007 18:07 PM    #

    Hi Jerry,

    Thanks for the great website. It should be recommended for any students/apprentices in the auto repair industry even if they aren’t interested in electric vehicles. The depth you go into explaning how things work and the pictures are superb.

    I have been in the auto repair industry for over 25 years and have had an interest in electric cars but never did anything about it. I am now self employed and I am seriously considering converting a car for my commute to work (10 miles each way in slightly rural and hilly Scotland). However enough rambling, while reading your progress on converting Eve you mentioned using an alternator driven off the motor to charge the 12v battery instead of a DC-DC converter and that got me to thinking. My ideal donor car would be Escort/Focus size and diesel powered (heavy duty suspension on a diesel). A lot of diesels have a vacuum pump on the back of the alternator so if this is rigged to the drive motor you would save the cost of a convertor and vacuum pump. The alternator/battery light would come on whenever the car was stationary but that could be solved with some clever wiring.

    Regards, Greg

  18. jerry Halstead    Feb 25, 2007 19:52 PM    #

    Hi Greg,

    If you happen to remember or come up with some of the models of cars that have the combo vacuum/alternator be sure to drop me an email or post it in a comment. I’ll try to put together a page of useful things to know, like that, rather than have them be obscure. Someone told me about cars with electric vacuums, but since I haven’t saved it or posted it in an easy to find place I can never remember what year/model they are.

    Great to hear from you and thanks for the nice comments.


  19. — James May    Feb 26, 2007 08:15 AM    #

    Hi Greg

    I am in the UK too if you need any UK specific help

    My car has a dc dc converter and a proprietary 12V vacuum pump for the brakes, so that’s one way of doing it. The electric vacuum pumps have the advantage of only drawing power on demand.

    The vacuum pump would have originally come from AVT in Somerset

    James (Coventry)

  20. — Greg Fordyce    Feb 26, 2007 08:25 AM    #

    I’ll see if I can compile a short list from cars that go through my garage over the next few weeks and post it here. The other option would be to go to your local car breakers and find a suitable alternator. Many or these vacuum pumps are connected to the engine oil supply so that would have to be got around somehow, or find one that doesn’t need an oil supply.
    Also diesel alternators usually supply a tach signal for the rev counter which could be useful. The vacuum pump would require a vacuum reservoir and you might find that you don’t have any brake assist after the car has sat for a while, I suppose a gentle blip of the throttle in neutral to spin the motor and alternator would build the vacuum.

    This information probably won’t be of much use to those of you in the States but in Europe there are a lot of small diesels running about.


  21. — Dan P.    Mar 06, 2007 03:56 AM    #


    Hope it is what you are looking for.

  22. Greg Fordyce    May 30, 2007 16:49 PM    #

    Hi Jerry and congradulations on your new arrival, Zane.

    A few months ago I posted an idea of using an alternator with vacumm pump but have now gone off the idea for 2 reasons.

    1- I have started a conversion of a Volvo 440 and am going to use a clutchless design which wouldn’t work well with a vacuum pump and alternator permantly attached to the motor. The drag from them would put extra wear on the gearbox syncros.

    2- Realized that the brake servo would lose vacuum in stop and go traffic because the motor wouldn’t be turning enough to build up vacuum.

    So I will source an electric vacuum pump and use a battery for the 12v supply, at least for now.

    A bit more about my conversion, As I said it is a Volvo 440, Stated curb weight is 1000kg and gvwr is 1580kg. After removing engine and related bits, car weighed 720kg leaving a decent capacity for batteries.

    I have sourced 17 12v 100ah gel batteries, these were unused old stock and I couldn’t refuse the price. Will initially use 12 for a 144v system but am going to experiment with different configurations such as 16 in a series parallel arrangement at 96v and longer range.

    I have ordered a Curtis 1231c controller and NetGain 9” Impulse motor. Originally was looking to use their WarP 9 (similiar to ADC 9”) but when I got the tape measure out I realized the length would be a problem in the front wheel drive engine bay. The Impulse motor shares components with the WarP motor but is shorter making an easier installation.

    I have read some of James May’s posts regarding battery monitoring which I have found helpful and interesting. I also saw the PakTrackr on your site and have ordered one.

    Another idea from your site that I am using is individual battery chargers. Ring make a “SmartCharger” that is a 12v 16amp charger in a very small case (once its chopped down, most of the case is cable storage)

    I would like to connect the rev counter and add a rev limiter for the motor. Does anyone have any ideas on this?

    Thats all for now, but should have a website up in the next few weeks at www.go-ev.co.uk.


  23. — James May    May 31, 2007 07:25 AM    #

    Hi Greg

    Sounds really good!

    Re. the battery monitors:
    You should keep encouraging me to post my full circuit board diagrams and instructions, otherwise the danger is that it’ll get de-prioritised and won’t happen for a long time.

    I have been wondering about going clutchless myself. I guess you think that the momentum of the motor and shaft won’t be too much for the synchros.
    I am runnning regen as well so I’d maybe have to suppress that on “out of gear” otherwise it’ll act like the weight of a flywheel on change-downs.

  24. — James May    May 31, 2007 07:35 AM    #

    Hi Greg

    Re the rev limiter:

    one of the previous owners of my car has implemented an analogue rev- limiter. It uses a frequency to voltage IC and voltage comparator ICs. It just cuts the 12 to the controller via a relay and the motor power stops.

    It’s a bit crude. If you over-rev the car it just cuts out in the middle of the road and takes a couple seconds to restart as the controller self tests (you have to also take your foot off hte accelerator). I have a 3 second delay circuit which I might put in to delay the cut-out and display a dash light. Then you would get the warning to lift off the accelerator.

    The revs pick-up is a magnetic pick-up close to a lightly castellated wheel on the motor rear end. I think it is a Fiat item. It gives a truly rubbish noisy signal. I have amplified it and filtered it a little and I use it for a rev counter signal but it is unreliable and bounces round. If you can use an opto pick-up I think it would be better.

  25. Greg Fordyce    Jun 02, 2007 09:11 AM    #

    Hi James,

    I have been thinking of a similar idea but using a hall sensor instead of a magnetic pickup. The hall sensor will supply a dc square wave which should drive the existing tacho. I was also thinking I might be able to use an off the shelf rev limiter but instead of cutting the power to the controller, short the potbox wires together so the controller thinks I’ve let off of the throttle and wouldn’t have to wait for the controller to reset.


  26. — James May    Jun 03, 2007 17:35 PM    #

    Hi Greg,

    That sounds like a good idea. Has the controller only got 2 wires to the potbox?
    I think, for a standard 4 stroke, 4 cyl tacho you’ll need 2 magnets diametrically opposite on the motor shaft or flywheel for your hall sensor.
    I think it would originally have been 2 sparks per crank rev, 4 per cam rev. Correct me if I’m wrong, anyone.

  27. Greg Fordyce    Jun 07, 2007 12:55 PM    #

    Hi James,

    The Curtis 1231C only uses 2 wires to the potbox and you are correct in assuming 2 magnets for a 4 cylinder engine although the tacho on this car is driven by the engine ecu and not the ignition coil so it could be different, but not likely. I think I may have found a solution for a rev limiter. Found this company, http://www.splatco.com that make progammable controllers, works on 10-24vdc and can accept an rpm signal. I have ordered one and will also use it not only as a rev limiter, but to activate the controller with inputs from key switch, battery charger, throttle microswitch, etc.


  28. Mark Jeffers    Jun 07, 2007 17:18 PM    #

    I couldn’t figure out where to post this question, so here it is: does anybody know someone who can program a Curtis controller, in south west Ohio? Or where I can rent a 1311 Curtis programmer? Thanks!

  29. Greg Fordyce    Jun 11, 2007 13:03 PM    #

    Hi Mark, can’t help you with a programmer, but have you tried contacting Curtis , they may have a dealer/customer near you who might be able to help.

    James, if your out there I have a UK specific question, I am about to send my vehicle log book V5 document (pink slip for those of you in the states) to the DVLA to change the fuel type to electric but I wanted to know what your V5 has as fuel type, battery or electric?

    Thanks in advance,


  30. — James May    Jun 11, 2007 13:29 PM    #

    Hi Greg

    On my V5C document it has
    (after wheel plan)

    Revenue weight “”
    Taxation class “ELECTRIC”
    Type of fuel “ELECTRICITY”
    Cylinder capacity “”
    CO2 “”

    without the quotes of course

    HTH James