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Auto conversion to Prius drivetrain

Discussion in 'Gen 2 Prius Technical Discussion' started by samuraikm, Jul 17, 2006.

  1. samuraikm

    samuraikm New Member

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    Hey all! I would like to know if anyone has placed a Prius hybrid engine into another vehicle. Currently I have an old Nissan Axxess that dropped its transmission about a year ago. Transmissions of the 2.4L AWD type are REALLY hard to find. So I was thinking of purchasing a damaged Prius (undamaged engine) and installing it into the Axxess. The Axxess specs out PERFECTLY with my '06 Prius in size, engine space, and hybrid battery space. The Axxess sits much higher than the Prius, so bottom space is not an issue either. I think it would be acceptable to tie the Prius drivetrain to the floating differential on the Axxess, as the engine specs for the Prius is smaller (1.5L vs 2.4L). I expect to totally gut the dash of the Axxess (there is plenty of space for the MID and CD) or just replace the whole dash with the Prius dash. All electronics should be nearly the same with the exception of the doorlocks and Smartkey system and antennas. Both take a 11.9 gal gas tank, Prius's bladder type hopefully is not necessary or will not pose a space problem.

    I was thinking of replacing the Axxess with a 2002 or 2003 Prius engine. Does anyone forsee installation, registration, or other problems? The Axxess is not demo, the transmission died. Otherwise the car is PERFECT!
     
  2. efusco

    efusco Moderator Emeritus
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    "All electronics should be nearly the same..."??!!! Are you smoking Ganja?

    There are some 16-18 computers in the Prius, many are functionally necessary 'brains' to make the HSD work. And you can't just throw the "hybrid engine" into another car, you've gotta take the Inverters, the Motor-generators, etc.

    IMO, without expending funds far in excess of the cost of multiple Prii, there is absolutely no way to retrofit the HSD into your car.
     
  3. aaf709

    aaf709 Ravenpaw of ThunderClan

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    Yes, some may wish there was a Hybrids R Us place where you could convert your old car to a hybrid, but that's not available right now. It probably could be done, but way expensive.
     
  4. samuraikm

    samuraikm New Member

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    <div class='quotetop'>QUOTE(efusco @ Jul 16 2006, 11:06 PM) [snapback]287425[/snapback]</div>

    Yes, yes. Obviously all electronics need to be transferred. The ones not tagged according to the electronic specs from both vehicles are the SKS, variable speed wipers, airbag subsystem, VAR and antilock braking systems. But no systems critical to the operation and functionality of the Axxess, all are present and at proper voltages.
     
  5. KMO

    KMO Senior Member

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    I think Evan's over-reacting a little.

    It would be an interesting exercise, possibly not terribly easy, but certainly possible, if you can manage to fit the engine, transaxle and battery mechanically. The the rest of it "just" involves transferring all the main control computers and associated wiring.

    The problems are going to occur where you have to interface between Prius and existing systems. Personally, I suspect instrumentation might be one of the trickiest problems. Either you transplant the Prius dash, or you're going to have to sort out some sort of display of your own. The Prius dash (and MFD) use the buses to get a lot of their info; it's not just individual wire signals. Hmm, maybe you could dismember the Prius dash to get at its control computer, and route the LED signals out to the Axxess's dash.

    It would certainly a be a lot easier to find replacement original parts, but if you want the cachet of having the only hybrid Nissan Axxess, then it may be fun to attempt.

    It's not really much more hare-brained than attempting an EV conversion of a car, and people do that quite regularly. The difference here is that the parts you're installing are mass-produced, proprietary systems, so you'll have slightly less scope for modifying their behaviour; you'll have to adapt around them. The whole project might be better thought of as a body transplant for the Prius, rather than a drivetrain transplant for the Axxess.
     
  6. efusco

    efusco Moderator Emeritus
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    <div class='quotetop'>QUOTE(samuraikm @ Jul 17 2006, 12:36 AM) [snapback]287435[/snapback]</div>
    Let me begin just a tiny list of the issues you'd have. And I'm not concerned in the least about non-critical functions such as SKS, wipers, air bags, etc.

    HV ECU--this system is not just a couple of wires attached to the ICE, it is a slew of wires integrated into nearly every function of the car, it ties into the battery, the brakes, the inverters and MGs, the speed sensors, the catalytic converters, etc. Some of this might be bypassable, but doing so would probably require a complete reprogramming of the ECU itself.

    Battery ECU, recieves data from the regenerative brakes, the ICE, the MGs the Inverters. Again, you could probably figure out how to bypass some of this, but not without a major reprogramming.

    One would need to figure out how to safely install and electronically shield all the various components.

    Again, I don't mean to overreact, but accomplishing this would be a nearly futile exercise. It might make more sense and be more feasable to adapt something like Honda's hybrid system however.
     
  7. Presto

    Presto Has his homepage set to PC

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    It'd be easier to rip off all the body panels on a Prius and weld on the Axxess body pieces, and call that a conversion ;)
     
  8. naterprius

    naterprius Senior Member

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    If you are going to all the trouble, why not put it into something cool, like convertible? Or an MR2?

    Nate
     
  9. matteo

    matteo New Member

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    <div class='quotetop'>QUOTE(naterprius @ Jul 17 2006, 09:00 AM) [snapback]287559[/snapback]</div>
    Or a Lotus Elise. They are already using the old Celica motor.
     
  10. ken1784

    ken1784 SuperMID designer

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    Another tough part is replacing the entire brake system which is called brake-by-wire.

    Why don't you convert it to EV?
    http://www.electroauto.com/

    Ken@Japan
     
  11. hdrygas

    hdrygas New Member

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    What a bunch of sick in the muds, if one had the skills it would be fun! I might take a while but there would be a certain satisfaction. It is out of my league but I can understand the attraction.
     
  12. galaxee

    galaxee mostly benevolent

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    well, i could see installation being the major problem. there are oh, 40something computers in the car. if it ties into any of the ecu's in any way, it's gotta be transferred.

    a couple major things:

    you'll have to retrofit a steering rack and steering column since there are no belts to drive a power steering pump. the braking system will probably be the thing that really breaks the project, even if you had the time/money/energy to do this. regen braking is a big source of battery charge.

    but hey. if you wanna try it, more power to ya. ;)
     
  13. hdrygas

    hdrygas New Member

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    <div class='quotetop'>QUOTE(galaxee @ Jul 18 2006, 07:52 PM) [snapback]288512[/snapback]</div>
    I would bet that DH would take it on! I won't mention it to him but IFixem has designs on doing something like that.
     
  14. statultra

    statultra uber-Senior Member

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    in 2 years i am going to take a try at doing a prius conversion, i dont believe its too hard, considering i fixed up two salvaged prius', all that you need is a perfectly good wiring harness for the vehicle.

    what it hink the procedure for doing this swap is :

    1. Disconnect HV Service plug
    2. Drain all fluids (brake, some engine oil, inverter coolant, maybe hv transaxle )
    2. Disconnect the inverter, two ( or 3 on the 04 not sure ) HV plugs, and the 3 or 4 wires to the elec motor ( 3 bolts )
    3. Disconnect inverter circuit breaker sensor, and the 3 wires on the right side of the inverter.
    4. Remove inverter ( take out the neccessary bolts)
    5. Remove air cleaner
    6. Disconnect fuel injectors and spark plugs
    7. Disconnect throttle body motor connector
    8. Disconnect the sensors located on the front of the electric motor and air compressor and such.
    9. Disconnect the fuse boxes ( not too sure if you can ? )
    11. Remove the thingy that the exhaust is on, including o2 sensor connectors, and insert random other connectors
    Then im not sure what to do from here, either go in the interior of the car strip it and disconnect all ECU's and pull the wiring harness through the firewall into the interior. then..
    10. Support the engine and transmission with a jack and remove the mounting bolts including torque rod and remove the engine and trans.
    12. Pull the rear of the interior apart, and disconnect the two HV wires behind the back seat, then route it through the floor and remove the high voltage wiring ( this is for the HV battery to inverter connection )

    also during this swap i believe the SRS will not work, or it will, it depends on the vehicle you are converting, i believe most new toyota and lexus's share similar airbags, but i believe the SRS is also connected through the HV ECU and the ECM, this is due to the circuit breaker that shuts off power in the event of a airbag deploying , seatbelt charge releasing etc.
    and im tired so i wont continue maybe tommorow

    oh yeah, after the swap you need to make sure that all the wiring harness's are properly stowed away in the safe places, especially the HV wiring that runs from the rear, also the ambient temperature sensor and random other stuff thats on the prius, its simple, just i hope toyota used connectors on the harness that are different for different ECU's, because im not sure how you would figure out which plug goes to which ECU

    im not sure if this applies to the 04-06 but i have worked on the HV system on the 01, including removing the inverter and charging the HV battery, so from the best of my knowledge i think this would be the way to do a swap. i have done a swap on a honda civic that i got for 50 dollars, and i think the prius is no different ( minus the emmense amount of wiring harnesses in the car.
     
  15. Frank Hudon

    Frank Hudon Senior Member

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    call this number and ask for George, he's doing this conversion on Dodge Caravans. 604 438 6611
     
  16. itjstagame

    itjstagame New Member

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    Any updates, anyone else tried this? I had half-hearted thought about this a bit because I really hate automatic transmissions but really love my wifes ES300 or maybe get an RX300.

    Was thinking that either of those with a blown engine/tranny and gut them out to make a very slick and economical machine. Of course that's only a someday thing because I don't really have any funds and even parts priuses are waaay pricey.

    I'm suprised by the very confused knowledge here though, why do some maybe people think the brakes on the car are special and generate electricity? The Prius uses MG1 for regenerative braking. It does have a special brake pedal system that engages MG1 regeneration first and then applies actual hydralic brakes as needed. This could probably be either swapped over or my thought (ghetto, I know) would be to back off the existing hydralic brake pedal on a car so there's a bit of play or slop, so I press down for 1/2"-1" before I actually start engaging the master cylinder (and hence the hydralic brakes). During this slop area I either engage MG1 or add an actual TPS and increasingly ramp up MG1 until just when the hydralics will kick in. I'd have to play/engineer the Prius brake system a bit to be sure, but I'm sure something like that would work fine.

    As for power steering, why do you need it? Disable/remove that junk and go with manual steering. Unless you have a fullsize pickup you really won't notice too much of a difference. Remember the trick is don't just unhook the pump, you want to remove all hydralic lines from the steering column and hook the two on the steering rack in a loop (with fluid still), or else you'll have to fight stale hydralic pressure as you turn the wheels.

    The biggest part to me seems mounting the engine (building engine mounts, etc), mating the output of MG2 to the existing driveline, depending on the car, etc, it's probably easier to just swap the Prius axles and hub or possibly entire front suspension. Lastly, making an alcove for the batteries that will get cabin air, with a fan when needed but secured enough to not be messed with and closed off/far enough away the "god forbid" something fails and the li-ion pack explodes.

    After that wire routing and multiple 'brain' placements is basic car mod stuff, just rip out the existing wire and make it fit and then find the appropriate outputs for the dash and stuff if you want, but to run you probably don't even need that. Definately you want to pull over the main bus and MFD and not splice into the Prius harness at all. You only really need to do hook in the parking/driving lights and existing dash board indicators if you want to, I suspect the Prius dash is fully electronic and you are probably better off just doing some plastic/fab work to make it fit.

    Aside from a Lexus I think a first gen MR2 would be sweet. I love that car and would love more milage and power.

    Really the hard part is I'd like to know how the PSD connects to the engine, that is the bellhousing/bolt pattern and if other engines could be used. It'd be much nicer to use the 3.0L V6 from the lexus or maybe a black-top 4AGE, etc.

    It'd be even nicer to be able to swap out/upgrade the motors, get a 150HP MG2, 2 battery packs and an MG1 that will go -15k rpm to 15k rpm (instead of -10 to 10) and that'd be a screaming machine. I really want more MG1 range so I can go up to 55-60MPG in EV mode and also for a higher top speed. Because lets face it if it's going in and MR2 and we find out how to hook up a more powerful engine and MG2 then we will want to drag race it :).

    After that all that's left is to find out how we can fool or program the ECU to have a launch program, something that keeps the engine turned on and then right before launch revs to max HP/torgue output and holds that RPM the whole time, using the PSD to adjust drive ratio as needed for acceleration. I long to see the 60 foot time this could achieve.
     
  17. richard schumacher

    richard schumacher shortbus driver

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    Everyone needs a hobby :_>
     
  18. ragman

    ragman New Member

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    I bet it wouldn't be easy, but I have seen a Reliant K-car do a 9 second quarter mile so anything is possible. How are your fabrication and welding skills? Any good at geometry?

    I worked for a body shop on the mechanical and electrical side of the shop and I have seen some crazy repairs done to these cars involving removing the entire electrical system and replacing it. After the wiring is done, it is all fabrication and engineering. Its hard, but not impossible. (don't I make it sound easy?;))

    If you are in my area, I'll work on it with ya!
     
  19. alanh

    alanh Active Member

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    Effectively you'd have to build a Prius inside of another car body, at least if you wanted everything to work mostly correctly. The ECUs monitor all the car's systems, so if there's a piece missing they're going to complain.