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Discussion Starter #1
I am planning on converting my 2006 Scion Xb in Green Envy to all electric. I live in the Kansas City area and would like to find someone who has done a build to help me with it, any help is greatly appreciated.
 

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OP and I had a conversation off forum.

While my conversion has been quite successful (42k miles on conversion in almost 5 years of driving, no major failures) doing another xB I would do things considerably differently, owing to the changes in availability and prices of components. The Azure dynamics / Solectria system I have certainly works, but is getting to be outdated and who knows how long until something irreplaceable in the inverter dies. (The motor will probably last forever)

These days, a direct nissan leaf drivetrain swap would be a compelling alternative, as would using the leaf pack. My xB was built for a 100 miles range with a 32kwh LiFePO4 pack and has achieved that range on a single charge on several occasions. A 24kwh leaf pack would not be enough to get that range, but a 30kwh definitely would. I know that my LiFePO4 pack had a few cells that probably never met their 100ah spec (I figure the weakest one was probably more like 75-80ah) so a strong 24kwh pack would probably be good for 75-80 miles and a 30kwh leaf pack would probably approach 100 miles in the chassis, all else equal to mine.

I have been known to tow an 5x8 tall boy enclosed utility trailer with my xB (which clobbers the range) but is doable even with the direct drive, as long as I stay away from starts/stops on steep hills. Because I sometimes use that way I would seriously consider a single stack remy HVH250 and appropriate 100kwh-ish inverter, attached to a stock or somewhat modified original transaxle. The transaxle mod would be removal of reverse, 5th, and maybe 1st/2nd ratios to reduce friction and spinning weight. What exactly I would do would depend on how easy it was to make the modifications. I removed reverse and 5th in my MR2 conversion, but I've never looked at the innards of an xB 5 speed, though I presume the design is similar. Battery in this setup would still be leaf cells, ideally a 30kwh one if I were doing it again.

The lower voltage AC50 / curtis 1239 system attached to the original transaxle would also work well in the car, and the leaf cell modules could be paralleled to get the AH up to a respectable capacity at 144v nominal voltage, though it would be less overall capacity than the equivalent of a full leaf pack.
 

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While my conversion has been quite successful (42k miles on conversion in almost 5 years of driving, no major failures) doing another xB I would do things considerably differently, owing to the changes in availability and prices of components.
While available technology has changed, that xB still serves as an illustration of available space for battery mounting, the practicality of a single-ratio transmission with an AC motor, and the energy needed to move this weight and shape of vehicle in real driving.
 

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These days, a direct nissan leaf drivetrain swap would be a compelling alternative, as would using the leaf pack.
I agree that this is a natural for a complete Leaf drive unit, since it already has the same configuration (transverse front-drive, and McPherson strut front suspension) as the Leaf, and the vehicle size and type is similar.
 

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... I would seriously consider a single stack remy HVH250 and appropriate 100kwh-ish inverter, attached to a stock or somewhat modified original transaxle. The transaxle mod would be removal of reverse, 5th, and maybe 1st/2nd ratios to reduce friction and spinning weight. What exactly I would do would depend on how easy it was to make the modifications. I removed reverse and 5th in my MR2 conversion, but I've never looked at the innards of an xB 5 speed, though I presume the design is similar.
I understand the reasoning behind removing unused gears from the transmission, but I'm not sure that reduction of rotating mass is a significant effect. After all, most conversions using the original transmission retain the flywheel, which has far more rotational inertia than any gears in a manual transmission would. I also wonder about what gears to remove. Omitting reverse is obvious (with an AC motor), but if the ability to shift between two gears is to be retained, it would be good to have them usefully different. 3rd and 4th are usually only about 30% different, so I don't know if it makes sense to keep just those two. I would think that whatever pairs of gears share a dog clutch / synchro set (typically 1&2, 3&4, 5&6) should be retained, but none of those pairs seem likely to be two useful ratios covering the desired range between them.

According to Wikipedia, the first-generation xB uses the C50 transaxle, also found in other similar Toyotas, such as the Corolla; related "C" transaxles are found in other small Toyotas, such as the Echo/Yaris.
It looks like first-gen (Corolla-based) MR2 use the same transaxle, or similar C52, or E51 (supercharged only), while the second-generation (Celica-based) MR2 has an E153 or S54 (depending on engine) - I don't remember what MR2 this was. All of these transaxles should all be reasonably similar in design. Whatever the details of the design, it should always be possible to remove one gear of each pair (the one with the synchro), although spacers might be required if the other gear sharing the shift fork is not removed.
 

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you are absolutely right about the gears sharing clutch/syncro components. So removing just 1st would be more complex than removing 1&2 together. One thing I might do to retain 2nd but lose the gear friction from first would be to grind off the teeth and as much diameter as I could while not having the assembly fall apart, but it would be more work. I did grind the dedicated reverse engagement teeth out of the MR2 transmission. These days I would grind first, then turn on the lathe to smooth it up more.

this chart shamefully stolen from the scionlife forums showing ratios for the xB 5spd:

1st 3.54:1
2nd 1.90:1
3rd 1.31:1
4th 0.96:1
5th 0.81:1
Reverse 3.25:1
Final Drive 4.31:1

The base speed and advertised specs on a standard HVH250 (http://evwest.com/support/remy250.pdf) running at 320V is actually pretty similar to my AC55 it turns out, though the HVH250 is waaay lighter and has more low end torque.

So compared to my current fixed 4.8:1, having just 3rd and 4th for example would give me a 4.3 and a 5.59 ratios. That would be a decent split to have in the car for better top speed and better city/hill/towing torque. Combining that with the HVH having ~300nm of low speed torque (the AC55/solectria max low speed torque is theoretically ~200nm, but the UMOC inverter software limits torque at stall to about half that) so it looks like at least theoretically I could have at least double (4th) or triple (3rd) my current starting wheel torque even with just a 2 speed setup. Given that I can already now almost spin the tires dry (easy wet) That would be more power than I could use, without also upgrading to an LSD of some sort.

With just 3rd and 4th I'd probably go clutchless. at minimum I'd do what I did in the MR2 and get an aluminum flywheel and knock the ring gear off of it.

1st was too low to be useful in my MR2. I think I used it once climbing a steep dirt road. I did use 2nd a lot though. However it was a 120v DC lead sled conversion with a curtis controller. If I were doing a RWD conversion and modding the transmission I would probably leave 1st and 2nd. I think traction will be gone before the extra torque could be used in a FWD like the xB.
 

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The base speed and advertised specs on a standard HVH250 (http://evwest.com/support/remy250.pdf) running at 320V is actually pretty similar to my AC55 it turns out, though the HVH250 is waaay lighter and has more low end torque.
The HVH250 also has a broader speed range (so it can use more reduction) and maintains power much better at high motor shaft speed (so higher speeds are more usable).

Remy was purchased by BorgWarner, so this is the current web page for this motor series:
HVH Series Electric Motor
I don't know of any change in the actual product.
 

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Discussion Starter #9
I would like to thank both of you for all of the excellent ideas you have suggested and will keep you posted on the build.
 

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Discussion Starter #10 (Edited)
Some more questions about using LEAF components

Question 1. Would I be able to keep the Scion wiring harness, or would I need to adopt the LEAF wiring harness to the Scion?



Question 2. What part or parts would you try to purchase first to gather the need parts over time?



Question 3. Would it be worth waiting for a used 2019 long range car to be parted out, They are supposed to be increasing the range substantially.


Thanks in advance for all the time you have spent helping me.


Michael
 

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Question 3. Would it be worth waiting for a used 2019 long range car to be parted out, They are supposed to be increasing the range substantially.
The 2018 Leaf already has a 40 kWh battery, compared to 24 kWh and 30 kWh of earlier versions. Yes, a 60 kWh battery is anticipated for 2019, but I don't know how much capacity you really need... or are willing to pay for. There will always be more capacity later, which could be considered a reason to not wait (because if you wait for the ultimate solution you will never build anything), or just to wait to buy until you are ready to build.

The 60 kWh battery is expected to be substantially different, so nothing about working with the Leaf battery that has been worked out by DIY builders will likely apply to the new battery. Since the current battery design is well understood, if using Leaf components it makes sense to me to design and plan for the existing battery (preferably accommodating the glued-together double modules), taking advantage of a 40 kWh unit if it is affordably available when it comes time to buy one.

The 2018 Leaf also has a significant increase in motor output (to 110 kW from 80 kW), probably due mostly (or entirely) to inverter changes; the 2019 is expected to go further, to 160 kW. On the other hand, even the earlier Leaf has enough power for an xB.
 
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