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309 Posts
Discussion Starter · #1 · (Edited)
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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309 Posts
Discussion Starter · #2 · (Edited)
Day 1 - Decoding Toyota Tach signals?

First day of "work" (if you can call it that).

Took lots of measurements, played with sensors etc...

For the record, stock vehicle height (ground to fender) is:
- front: 31"
- back: 30"

Originally I was going to put resistors into all wiring harnesses to sensors
etc... (to fake out the ECM to think it was still connected to an ICE so the
Check Engine Light (CEL) would not activate) - I quickly gave up on this as
there must be >20 sensors on this thing - some have 4 or 5 wires (not
just simple resistive circuits). I will probably re-wire the CEL light to be a
trouble indicator from the controller or batteries (to be decided).

Along the way I got to use my ODBII code reader - I bought an
inexpensive ELM327 USB device - you connect one end to your computer
(drivers and software are a free download) and the other to the ODBII
port, and you can read codes, clear codes, see about 100 different engine
measurments etc... Highly recommended for the $50 it costs.

The only real sensor I have to deal with directly is the crankshaft position
sensor (CPS) - I believe this drives the tachometer, so I will have to
interface to the stock wiring harness in some way. Here is where the fun

Before I remove the gas ICE, I connected an oscilloscope to the CPS
signal (2 wires), then recorded what it looks like at different RPMs.
The scope is set for 5V per division, and 1 msec per division.

Here is what I saw (again everyone loves pics):
- idle (dash tach shows 750 rpm)

- 2000 rpm

- 3000 rpm

This translates into:
Tach RPM CPS Signal Ratio (CPS Hz/Tach Hz)
750 +/- 6V (peak), 425 Hz 34.0
2000 +/- 12.5V (peak), 1222 Hz 36.7
3000 +/- 12.5V (peak), 1777 Hz 35.5

36 seems like a nice round number, so this indicates that for every turn of
the motor, I have to generate a 36 Hz sine wave.

I was a bit surprised by the sin waves - I was fully expecting square
waves (perhaps PWM), which were either -12, 0 or 12V - has anyone else
seen this with a Toyota tach signal?

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309 Posts
Discussion Starter · #5 ·
Re: Day 1 - Decoding Toyota Tach signals?

36 seems like a nice round number, so this indicates that for every turn of the motor, I have to generate a 36 Hz sine wave.
I just noticed that the oscilloscope was set to AC coupling, which removes the DC component... I was still expecting a square wave which was either 0 or some other voltage... I think the AC coupling in the scope may also be distorting the waveform somehow...

I will repeat the test with the DC offset kept.

Google searching is amazing - I found this video explaining the different sensor types:

I probably have a Hall effect type sensor,,,

I still think I need a 36 toothed wheel (or maybe 34?)... I haven't found a picture of the crank timing pully from this engine - it will look something like this (although this is from a different Toyota engine):

I am still digging to find out more about Toyota VVT - I think the CPS (or CKP) sensor also feeds the spark plugs (there are igniters directly above each cylinder) so I do not want to generate a test signal into the ECM when the engine is still connected - the tach test may have to wait until the engine is out.

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309 Posts
Discussion Starter · #8 ·
Thanks Rob/Dimitri:

The height restriction means low amp batteries - this pushes the higher voltage design. I agree that this is a problem for the Warp motors - I hope the Warp 11HV motor is available soon ( as this sounds ideal.

Once I remove all junk, I will take more accurate measurements and see if those 240Ahs will fit, which gives me a LV option...

I have the Haynes manual, but it is not great. I looked but am having problems finding the 2001 RAV4 factory service manual - Toyota has a TIS service that allows US citizens to download all for $15 for 2 days, but this is not available to Canadians...

Dimitri - I re-read your build thread and now I understand - interesting that yours had only 35 teeth. I will go to a wrecker and buy the 36 tooth crank timing sprocket as well as the stock crank position sensor. I plan to keep a rear shaft on the motor, and will use it for the A/C compressor (no A/C when stopped though). I will have to figure out what size of pulley to use (as the motor rpms will be higher than the stock ICE) and how to mount the toothed wheel to the pully...

Thanks for the feedback - much appreciated!

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309 Posts
Discussion Starter · #10 ·
Thanks Dave - I see you have been there - done that. I will plan to keep the ECM and tach as-is - hopefully I can add the stock crank sensor and toothed wheel to the rear shaft, and it will all work...

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309 Posts
Discussion Starter · #13 ·
Dave - I think they work the same as yours - toothed wheel on crank pulley, into Hall sensor, then into ECM, and out to the tach. I have not found the VSS yet, but I think you are right that it is in the transmission - I will keep the stock manual transmission and AWD transfer case, so I should not have to touch this. My airbags also seem to interface to the ECM (maybe they are speed sensitive somehow?), so another good reason to keep the ECM.

Bowser330 - good point on the Kostov's - I have been reading lots and they seem to be much more involved lately and a comeback seems on its way - all good!

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!

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309 Posts
Discussion Starter · #16 ·
Hi Dave:

The ECM even has wiring to the ABS braking system and A/C system (in addition to the airbags) - not sure if this is only for the check engine light/diagnostics, or if there is more to it. I think I will plan to keep the ECM for now.

I did spent some time mapping out all of the sensors and which trouble codes light up - I was originally planning to fake out each sensor with resistors etc... (so the CEL light would stay off), but it got too complex (the 1 or 2 wire sensors would be easy, but some sensors have 4 or 5 wires, such as MAF etc...).

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Discussion Starter · #21 ·
Some great ideas here - I think I will walk before I run though - will think about all of the other lights later... I would have to have lots of spare time on my hands to work on the "talking dash" concept.

Since we are day-dreaming, I eventually will add a car-pc - it will have GPS/navigation, rear camera, fm radio, media player, weather, wireless internet, e-mail, engine diagnostics/OBDII interface, battery monitoring, bluetooth cell phone and voice dialing etc... There are some nice touchscreens that fold into a double din pc enclosure (need to find a bright one that works at -40C though)... No shortage of things you can do once there is a pc onboard... "Flash" is important (again I defintely am not an EV purist with statements like this).

I looked for some general purpose analog to digital I/O boards to connect to the PC (need many inputs for battery monitoring) - instead I will probably get a PakTrakr, which streams a CSV string every 1 sec, which can be captured onto the PC and decoded, plotted etc...

One thing at a time though - first to pull the motor and ICE junk!

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Discussion Starter · #22 · (Edited)
Made some progress on Saturday - most of the junk is away from the motor, just have the motor to pull. Only hacked 1 part to bits (short exhaust section) and all parts in good condition... Lots of Toyota fiddling required though (I curse the engineer who designed the power steering pump mount!).

Key tip: Before you start, have the Air Conditioner refrigerant evacuated at a shop! Releasing the refrigerant (both R12 and R134a) is VERY bad for the environment. Rob (RKM) warned me about this and I promptly forgot. Fortunately I have a friend in the A/C business (thanks Malcolm!) who is bringing by a portable purging unit.

The A/C has to be discharged for 2 reasons:
1) to get the condenser out of the way to pull the motor (same size as the main radiator and directly in front of it).
2) To remove the interior heater core, it may be necessary to remove the evaporator coil (mine does require this).

Pictures next weekend once the engine is pulled and the engine compartment is free of the clutter.

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309 Posts
Discussion Starter · #23 · (Edited)
I had an portable A/C evac unit lined up, but residential A/C fittings are not the same as auto A/C fittings. Shops around here would not sell me the R134A fittings, as you have to show them an A/C license.

Ended up towing the car to a shop - $45 later, the A/C system is evacuated.

How NOT to tow a car:

PITA - but I couldn't release the R134 refrigerant into the air (legally and ethically - would have tainted my "green" REV4 . Wish I "had my ears" on and did this while it was still running...

Removed all hoses, and tied up the ends with plastic bags/elastics (to keep the air/moisture/rust out.

Good to have the A/C disconnected though - made for easy access (now that the condenser and hoses are out of the way). Since I will imbed ceramic heaters into the heater core, I will have to disconnect the A/C anyway (to get at the heater core).

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309 Posts
Discussion Starter · #24 · (Edited)
How NOT to Pull a Motor on a RAV4 AWD

How NOT to pull a motor:

1) Never use your child's swingset:

2) Use proper chain hoists
Come-alongs are not made for lifting.

3) Make sure you read the factory manual and drop the motor as recommended by the manufacturer.
Toyota factory service manual tells you to keep the motor and transmission together (I have an AWD, so its the motor, transmission and transfer case). I clearly thought this was smoke and mirrors, so managed to pull just the motor and went straight up. I liked this approach as it leaves the drive shafts, cv joints, steering, brakes etc.,.. untouched. That said, it is a pain to do.

If anyone else tries this:
- remove everything from the front of the motor (power steering, water pump, crankshaft pulley, A/C, alternator, passenger side motor mount etc...
- remove the front transmission mount, and lift slightly (to give room for the transmission to clear the lower frame member (or unbolt the frame member).
- separate the motor and transmission as much as you can, then unbolt the 6 clutch bolts (slowly releasing each bolt a bit at a time) - you can rotate the motor/crank and unbolt the bolts from the clutch to the flywheel from the top
- move the clutch pressure plate back onto the transmission and remove the clutch disc
- there should now be JUST enough room (1/2" to spare?) to lift the motor straight up - see photo below:

Despite these pitfalls, we managed to get the motor out via the top - hurray!
Photo below has some of the junk on the front re-added.

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309 Posts
Discussion Starter · #26 ·
Oh-oh - big problem! Which motor will fit?

Oh-oh - big problem...

Look at these pictures - top view:

Manual transmission is on the right, AWD transfer case (top) bolts to the transmission, and has a rear drive shaft exiting toward the vehicle rear (not shown).

and side view (zoomed in):

The manual transmission bell housing is plenty wide, but the transfer case (remember, this is AWD with a transverse motor mount) sticks out and really limits how big of a motor can fit.

I was hoping to build a rocket, and maybe use a Warp 11 or Warp 11 HV motor, but this clearly is out of the question. My fallback was to settle for a Warp 9, however even this is questionable.

The Warp 9 diameter is 9.25" - I have just enough room for 4", 19/32, equals 9.1875".

This is too close to call - can anyone confirm that the Warp 9 is exactly 9.25" diameter?

I thought about pounding in the differential cover on the transfer case, but it looks like some sort of composite and probably will not bend nicely...

Now I know why no-one converts AWD (and here I thought it was just the wasted range).

Any ideas?

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309 Posts
Discussion Starter · #33 ·
Dave/Jim: There is only 20 3/4 " from the transmission mounting surface to the passenger side frame. The Warp 9 is 20.19" (shaft to shaft), minus 1 or 2" where the shaft enters the bell housing, plus the thickness of the mounting plate - basically it should fit but no extra space for CV joints etc...

Kittydog2 - I only need a 1/16 ", so a custom diff cover is an option...

Jack - direct drive - hmmmm, I have never thought about this option before... Will have to see what the clearance is above the steering rack. I think there are 4 diff ratios in '01 RAV4's, depending on 2WD or 4WD, auto or man, the lowest is 3.12:1, the highest is 4.562:1.

I also thought of using a Kostov 9 motor (diameter 8.66") - anyone have any experience with these?

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Discussion Starter · #43 · (Edited)
I was planning on keeping the clutch - I like the idea of a mechanical safety/off switch (in addition to an electrical breaker) for DC runaway scenarios, plus easier gear changes...

I gave up on the direct drive idea - would consider this with an AC motor only (higher usable rpm range) - I don't think DC motors like operating at low speeds in the city. It is a 4.562:1 rear diff ratio though (unusually high)... I would loose AWD with this too (there is snow on the ground 5-6 months of the year around here).

I like the twin motor and CV ideas - there is not much room below as there is a frame member (which probably could be moved/lowered). I had the 36x24 area above the motor/transmission pegged for batteries.

I will pull the diff cover plate and see what it looks like - it looks quite thick from the outside, so will see how much grinding I get away with. Also good idea to shave the motor itself (although my warranty would be toasted likely).

On the bright side, sure glad I waited until the motor was pulled before ordering batteries, motor and controller - they are all linked together. Definitely recommended for transverse AWD builds...

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309 Posts
Discussion Starter · #46 ·
Thanks Thaniel, Dave, Jim, Rob and all - great ideas and advice. It is great to get help on these issues from people who have been through this.

The stock 2.0L engine has 148 HP, 142 ft-lbs at 6000 rpm.

I also think it is better to keep it simple. The diff cover of concern has some thickness which can be shaved - also worst case there is some clearance behind the cover so a custom/thin metal cover could also be whipped together as Plan B. The Warp9 should fit (perhaps with some "persuasion"/grinding). It will not be a rocket, but I am sure I will not be disappointed.

Thaniel - you are bang-on that the Zilla will also need a speed input (for over-speed control) and can drive the tach - I have not considered this yet - it does not make sense to have 2 tach sensors/circuits...

I will add a pulley onto the end shaft (for the A/C) and hopefully can add the tach sensor for the Zilla onto the end too (and use the Zilla output to drive the tach)... If the ABS brakes, A/C, or airbags do not work (hopefully the ECU wires for these signals are only for diagnostics) then I can weld the 36 tooth wheel, stock CPS sensor and re-enable the ECU to work in parallel. I am still waiting for the factory wiring diagram/manual to arrive (so far relying on Haynes manual - not so good) so maybe can learn more shortly.

So, Warp9 it is. Also a Zilla 1K is the most likely contender (although hoping to avoid liquid cooling).

I will post plans for the motor, batteries, controller etc... shortly... Now that a "low" voltage for the Warp9 is enforced, this will also input into the battery decision.

All other inputs appreciated - thanks all!

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309 Posts
Discussion Starter · #48 ·
THE PLAN - Overview

Now that the ICE is out and I know how big of a motor will fit, this guides everything else...

So, here's "THE PLAN":
- Motor: Netgain Warp 9
- Controller: Zilla Z1K HV
- Batteries: 50 TS200AH LFP batteries
- DC/DC converter: IOTA DLS-90
- Charger: Manzanita PFC20
- Interior Heat: 2x1500W Ceramic heaters
- Power Steering: MR2 electric power steering pump
- Brakes: 12V power brake vacuum booster

More details on each of these (and some factors of each decision) is in separate thread/posts below.

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309 Posts
Discussion Starter · #49 ·
Overall Front Layout

THE PLAN - Overall Front Layout:
- PS pump in bottom middle (near to the PS rack) attached to the belly pan
- Controller and charger mounted in the very front (where the original radiator and fans are)
- Brake booster at front driver side (far away from the cab)
- A/C pump in original location (passenger front, low) and mounted to motor
- DC/DC converter (not sure yet - hopefully room in bottom passenger side close to the 12V battery)
- Batteries on top of everything else (hopefully room to access the controller and DC/DC).
- Other wiring (relays, etc..) - not sure yet, probably hanging off front
- full belly pan (plastic of some sort?) to keep water out
- air handling/routing (to get air flow across batteries in summer).

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309 Posts
Discussion Starter · #50 · (Edited)
THE PLAN - Motor

THE PLAN - Motor:
Netgain Warp 9
- this will be tight (9.25" diameter)
- no room for anything bigger (probably have to shave 1/16" from somewhere
- backup plan is for a Kostov 9 (8.66" diameter)

I will keep the clutch, so a taper-lock bush and hub will have to be machined (not my expertise - I will find a machinist to do this). The inside of the hub also has to be drilled for a end-bushing (for the transmission shaft to ride in).

The "critical distance" (flywheel face to engine-transmission joint) is 1.30".

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309 Posts
Discussion Starter · #51 · (Edited)
THE PLAN - Controller:

THE PLAN - Controller:
Zilla Z1K HV

I also would consider Soliton1, but Zilla seems to have more software/protection features and has been around longer.

I am not super keen on liquid cooling, but it seems to be recommended. I haven't thought about the pump/mini-radiator yet, but will look around to see what others are using...

Defintely want over-speed control, so will probably use a sensor on the motor shaft into the Zilla, then use the Zilla to directly feed the tach (bypassing the ECU - thanks Thaniel). A bit of experimenting required here.
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