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2001 "REV4" - Build Thread

101279 Views 144 Replies 27 Participants Last post by  tylerwatts
Formally introducing myself - I am an Electrical Engineer working in power
systems (wind farms, HVDC links, machines etc...) and specializing in
computer simulation. I also have a bit of auto-mechanic experience (I
have owned a 1975 F250 4x4 Highboy since 1983).

I have been a long time lurker here - thank you all for the phenomenal
support/information - this is a great site!

I am also fortunate to have my nephew (Derek) helping me on this - he is
18 and will graduate from high school this year. He has an aptitude for
taking stuff apart and fixing things, so this is a win-win situation. I enjoy
working with him, and his help will be appreciated. We hope to work every
Saturday and maybe one evening during the week. I have 2 boys (6 and 8)
who play hockey etc... so I am already pushing the limits of my spare
time - this will be a very slow build...

I recently saw Rob's (RKM) Red Miata - this lit a bit of a fire, so here we go...

My overall plan is to convert a relatively new vehicle (>2000) and to make
an EV that works just like its ICE counterpart in all ways - it will have
power everything, heated leather seats, full trunk space, air conditioning,
AWD etc... The plan is to demonstrate that you do not have to give up
anything to drive an EV (in fact it will be faster and better). Of course this
will not be a cheap build, nor will it be a super-efficient low kWH/kM build,
but it will be a very driveable car I will use as a daily driver in all seasons
(also more on this later).

I really only need about 50kM of range per day, but given winter
conditions in Winnipeg, and my desire to not push any equipment close to
its ratings, I will try to squeeze in more batteries/range than what is
really needed.

I finally bought my donor and started work:
2001 Toyota RAV4, 135,000 kM, AWD

I choose the RAV as it is a family car (would love a light 2 seater
convertible but with a family of 4 it is a no go), has some height/weight,
plus it has a history/reputation for EV'ers (stock RAV4 Ev etc...). also
considered a Ford Escape or Honda CR-V...

Everyone loves pics (although this is only the stock car so far):

Yeah - I know - the big sticker on the hood has to go. You should have
seen the car before - it had "all available Canadian Tire options". I bought
an OEM leather interior kit, as well as some carbon seat heaters for driver
and passenger with 5 position dial (I can hear the groans from all the EV
purists who have scrimped on weight/features etc... to get max range!)

My "REV4" EV Conversion Plan (please - all comments/suggestions/feedback welcome!):
- Warp 11 (or maybe even Warp 11 HV?) motor
- Zilla HV 1K or Soliton1 (not decided yet)
- SE or TS LFP batteries, probably 65*100AH (more if there is room - more on this later)
- keeping the 5 spd manual transmission, have bought a new clutch

Note that the motor and controller are likely more than the stock
clutch/transmission/AWD system can handle - I figure that equipment that
is rated for higher duty conditions but driven "soft" will last longer, not
heat up etc... (definitely an engineer talking - over design it). I love the
power however, so will start with the max controller amps limited, then
increase it until everything feels shakey, then back it down a bit...

If the Warp 11 HV motor receives good tests reports, then it seems like a
no-brainer for the cost - I will use a high voltage and as many batteries
as I can fit.

I plan to put the majority of batteries under the hood (on top of the DC
motor, manual transverse transmission and AWD transfer case). There
also is room under the rear of the car where the gas tank used to be (2
smaller boxes) - keeping the 4x4 definitely adds a penalty here as the
rear drive shaft cuts everything into 2. I do not want to fill up the
trunk/back seat with batteries though.

The batteries are a big pain (a low-height LFP battery that can stick under
the floor pans would be killer) - in reality I only have about 11" to work
with (which means TS or SE 100AH batteries, which are 8.66" high - once
you add the BMS, enclosure, insulation and heating pads, this doesn't
leave too many options. There are also the new SE 240Ah batteries (6.73"
high, 17.72" long, 2.8" thick) but that massive 18" length just won't match
up with the room I have in the car.

Horizontal placement of the batteries would also work, but I have been
told by SE that this is not recommended and would void warranty.

I think I can fit about 20kWH of batteries into the 3 boxes - I will pull out
all the junk in the way before ordering batteries though (maybe a
reasonable priced A123 deal will come along between now and then?)...

One non-logical aspect to my choices are using a 1000Amp controller with
100AH batteries - 5C would be a huge draw (perhaps too much?) so higher
AH batteries would be a better fit - they are too darn tall however (or too
wide for the 240AH) so I am somewhat torn/stuck. All suggestions
appreciated here - what would you do?

I am undecided on many other parts - will be deciding soon though. I will need:

- electric vacuum pump for power brake booster (Rob/RKM showed me a
pump that was enclosed inside of the vacuum tank - that made sense to
- electric power steering pump (no-one in Canada has a 2000-2005 MR2
Spyder pump - trying hard to find one in US for a decent cost - let me
know if you find one!)
- hydraulic pump/heater for interior heat (will keep stock heater core and
fan/controls - I don't like the idea of electric heaters inside the interior
heater core)
- 1000 Amp contactors/breakers/fuses?
- battery heating pads (it gets to -40 deg in Winnipeg for a few weeks
every year and I have to get to work!).
- charger (I want a dual voltage 120/240 charger - 30 Amps would be lots)

I plan to pull the motor etc... soon (1 or 2 weekends from now) - I will
take careful measurements for the motor and batteries and make some
decisions then...

I have never done this (and definitely respect the people who have) so
please - all comments/suggestions appreciated!

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Congrats on the official start to your conversion! It almost sounds like a religious process doesn't it? I've been waiting for you to get this thread started. Let the journey begin...

Your's will be interesting to watch for at least a couple of reasons. First off, you are doing a high end build on a vehicle that will suit your family requirements. It sounds like you are prepared to spend the money and limit the compromise. Secondly, your background is electronics. I know you have ambitious plans for a tres cool control system interface.

Re. Batt selection

I don't want to sound unsympathetic, but the many of us who have wrestled to put batts in small cars are envious of the space available in an SUV. Had to deal with that first. I realize you still need to work with the dimensions available and that height is the real issue. My boxes are 13" tall from outside top of lid to the outside bottom. The cells are very nearly 11.25" to the top of the post. I have only about 1/4 of an inch to spare. The BMS takes up some space.

You had mentioned using 65 X 100Ah with a 1000A controller and pulling 5C. Maybe I missed it, are you intending two packs in parallel to get 200Ah which would give you 5C to drive the 1000A controller. If the 65 cells are in series, you would reach 10C to power 1000A (?). I know TS has increased the max surge rating to 12 or so, but I'd rather keep the draw as low as possible. My max C should be about 4.4 which is still plenty high. This string would also have a nominal voltage of 208, max 250. I'd be surprised if the Warp 11 will handle this high a voltage (Warp 9 rated to 170V). Are you planning to limit max voltage to the contoller?

If you opt for relatively low Ah cells, could you consider adding a cap bank to handle the brief high current load for acceleration?

I like those 240Ah, would make a great match for the controller. The height works so well, shame you can't fit the length.

Decisions, decisions. BTW, I appreciate your tongue in cheek comment defining spark plug!

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I also read about using the stock power steering pump attached to the motor 2nd shaft (see post 6 here: ). I now have the A/C, power steering and crankshaft position sensor sprocket all run of the motor. I think there is lots of room (below the batteries) so its worth a shot - I could always change it later and add the EHPS pump![/quote]


The obvious downside for PS off the tailshaft is that you won't have it when you most need it i.e. low speed parking. The EHPS pump from Toyota has worked well for me (okay only two miles driven).


Despite the hassle and cost, you know you did the right thing by properly evacuating the refridgerent. I think I told you this story already. When I contacted my local Ag dealer about a service call out to evacuate my AC, he looked at me and said "You know, most people would have an "accidental" leak." Like you, I explained that releasing the R134A to the atmosphere wouldn't fit well with a Green car project. It cost me $75 but that was a service call, no tow required.

Glad to hear your progress. Fun, isn't it?

Take care.


The most appropriate response to the intruding housing is DANG. Moving on...

I understand that you have a couple of priorities for this conversion; that it be quick and that it retain the AWD. If this is the case, Woodsmiths suggestion of running twin 8's should let you do this. The motors would be situated side by side or over and under and connected (chain, belt, gear) by the tailshafts. You would need to confirm how much power and torque the motor shaft can transmit of course. Twin motors would not be as space efficient or as economical as a single 9 or even an 11. I suspect you'll have the space.

RE confirming motor OD...I'm 99% sure the OD on my WarP 9 measured 9.25".

Lots of interesting suggestions. Jimdear2's comment re thinning the motor jacket is likely the easiest, aside from using a smaller diameter motor.


So, I know that you are a small business owner, a family man and that you were up at 3:30 am posting your schematics for your heater control (very impressive). You've got it bad Garth! Forget H1N1, the EV bug has already claimed you.

Lots of updates, looks like most of the ducks are in a neat row. I'll make a few comments;

I'm pleased with Brian's vacuum kit, though I don't know how it would compare with the alternative you list. I chose Brian's for its compact size (like the pump inside the reservoir, till it fails of course), to support a fellow EVer and for its economical price. The kit offered by EVcomponents looks excellent and was the other system I considered. I like the sound (no pun) of the oil muffler. This kit was over twice the price.

The DC-DC is a monster, which is good. Mine is about 2/3rds that size, which I think will be more than adequate given the buffer of the 12V battery. I haven't added up the sum of the 12V loads, I expect you will though. The largest single load will likely be the PS pump and that will only be a very brief load. Better too large than too small.

I thought you'd have lots of room for cells! I'm wishing I'd had room for more thorough insulation and a heating system (the Miata is that tight). Some recent posts are suggesting the performance of LiFePO4 in cold weather is not as good as I had thought. If you can accomodate it insulate and heat the boxes. Good for you to opt for Al. That was my intention, then I changed my mind for economics and convenience. I don't regret the decision. I'd estimate the steel boxes are only about 30-40 pounds heavier than Al would have been. I should be able to make up for that differential personally!

Long live the Zilla. Green is beautiful. I agree that motor over speed protection is very important. Bryan (Beltronix) did a great job with his option. It also provides a tach signal. Works great, saves a motor.

The WarP 9 shaft is machined for a pilot bushing. I don't know if your tranny shaft and motor shaft will reach each other or not. You may just need a sintered bronze bushing to get the correct match for OD/ID.

Very well thought out conversion!

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I think you've done a great job at designing an efficient, effective coupler for a challenging application. I say this knowing that the effort was 99.9% your's!

The sketch is impressive also. I use a different CAD program but may download SketchUp 7 and give it a try. It will be a real bonus if the software is compatible with the programming for the CNC equipment at the machine shop. Let us know about that!

I chose a similar bushing design, with inner and outer keys to have a mechanical connection between the motor shaft/bushing and bushing/hub. We all know there is a lot of torque through this connection.


Coming together nicely! The coupler looks great, congrats on an effective, efficient design.

Just for my own information... what scrap supplier had 3/4 Al plate in Winnipeg? I couldn't find any months ago when I was looking.

Your welcome to the use of my 4" hole saw rather than using the jigsaw for the motor/coupler pilot hole. You could use my post drill as well if you'd like. My shop is your shop!

Good to see progress.


You weren't kidding when you said it is a tight fit!! Looks like 0.010"! How far does the cover extend beyond the gear? I guess you'll make it fit.

Do you plan to use flat washers, lockwashers and/or self locking nuts on the adapter plate for the final installation? As you know aluminum is much softer than steel, would be a good idea to have a flat washer beneath the nut.

I think I recognize the hydraulic hose holder from Princess Auto! Where would we be without PA?!

Great to see progress.

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Glad to hear you're almost back on the road! I've used Nokians for years and think they are the best snow/ice tires. I have four on the Miata too. In 4WD, you'll be almost unstoppable.

To continue the Nokian commercial....

I regretted my choice of choice of words almost right away, "unstoppable". I agree that steering and braking are the critical advantage to good snow/ice tires. Being able to go is another benefit!

I bought our first set of Hakkapelita Q Nokians after a 15 cm snowfall on top of ice. I had been planning to buy the "WR" Nokians, which are good but which can be driven in the summer as well. On my drive over to the tire shop, the car felt like a curling rock as it would gently slide along with the brakes applied. I thought I'd be lucky to get to the tire shop without bumping into something or being bumped into. I called my tire guy (while parked) to change the order to "the best you've got". It was a night and day difference.

Under most winter driving conditions, our little front wheel drive car, with good snow rubber, is far better than the 4WD truck. The truck will handle more deep snow, but the car will stop and steer far better.

See you on the 27th.

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