[stillsearching]

I know this has been mentioned in the past on and off here but maybe someone could bring me up to speed because i'm not sure whether any projects ever got further than the brainstorming stage.

(and yes i'm bad for that too, lots of projects I tried to start two years back which have just ended up postponed due to things like work and school and friends who promised help not falling through, but that's how it always is, right? :P)

I'm wanting to more seriously look at the possibility for an electric FWD motor conversion on a large SUV and was wondering how close we are to having an off the shelf solution for that.


Basically to bring anyone up to speed on things i've already decided:
- Planning to use a 3/4 ton Chevy Suburban, either the older 73-90ish chassis or the newer 91-99ish update (the first downsize ever, first attempt at aero, etc. The later ones both are getting larger again and seem LESS aerodynamic plus cost too much for this to start), I expect to use a Cummins 6bt P-pump turbodiesel, NV4500 manual transmission, with an expected max tow of 9990lbs. I would like to use 3.07 or at worst 3.42 axle ratios on normal highway towing tires if that's not too numerically low for startability with that tow weight on a 7% grade but the NV4500 has a steep granny gear helping things. 95% of tows would not be Rockies anyway let alone that weight usually through there. But some future tows WOULD go through there perhaps at max weight to pay the difference of the extra capability just not enough to design the whole vehicle to routinely do it.
- Yes this has to be a Suburban, not a little economy car, because of basic physics of both peoplemoving and towing. I hope to drive a small Jetta with a trailer whenever possible for efficiency, but this is for when I can't and adding a humans-only minivan for when i'm moving 7 people/traveling doesn't justify a third vehicle after carefully analyzing how often it'd be used vs further mpg savings. FWIW improving 2mpg on an SUV is worth alot more than improving 2mpg on an econobox and human-only travel will be much less common than towing (but would be a full load when it happens).
- Because of towing realities this needs to be a RWD-normal vehicle with FWD-electric assist added, rather than an FWD conversion (which i'm aware is more efficient) with RWD added. This needs to be a reliable tow vehicle first that will always get me there and out of there/muddy fields for farm and ranch duty, rather than a max-mpg peoplemover. The biggest MPG savings will be taking the Jetta whenever possible which I will do!
- Yes I hope to fully aeromod this (both vehicle and trailer and coupling them) but i'm exploring whether it's worth it to then reduce mechanical inefficiencies vs the simplicity of just getting part time 4wd. I'm looking for an honest discussion of what specific motors, bolted where, what batteries or controllers would cost, etc - like if you wanted to do this this year how would YOU do it? Secondhand salvage ideas and unorthodox thinking to drop the ticket price is the whole reason for posting this!
- Simplicity wins over best. Less of my pie-in-the-sky dreaming (me wishing for 7 speed medium duty transmissions with the extra fab hassle or uncommon but more efficient engine swap options) and more off-the-shelf get'r-done because otherwise the best solution will never get built. Possible upgrades in the future to stuff like that but not now - I would like something on the road within 2 years from now and need to know how i'd do electric-fwd conversion if I later choose to.


I've no idea whether the best solution is to start with a 2wd chassis or a 4wd chassis - but i'm guessing my main options are either stick an electric motor to the front differential sorta replacing the transfer case, eliminate the differential and stick motors in place of the CV joints (in a 4wd suspension) or stick motors right IN the hub (with either 2wd or 4wd suspension) and i'm open to any of the three (or other) options - plead your case!

I am still up in the air about under what all conditions I need 4wd. There may well be some inexpensively put together system that would provide grip and mobility up to 8mph that would cost a fraction of what one would up to 55mph I mean. This has to be able to drive into a muddy rancher's field 400 miles from civilization and not need a tow every week doing so so the 4WD is nonnegotiable, but it's primarily about not getting stuck or getting unstuck at low speeds until back on the highway. I might not even need truly variable throttle in the controller for that/might just be a couple 'steps' to keep wheels moving.

That said if it's not a huge price difference something that could add stability at highway speeds would be nice sorta like AWD does - this will be a peoplemover at times with kids and that's a safety enhancement if I could turn on the front drive the moment wheel slip was detected for instance. For that matter something that would actually add power would be nice too. I'd considered leaving the cummins around 160-200hp and seeing whether the electric motors could provide the power boost since it seems diesel jetting is most efficient if sized for constant instead of peak load. If the machining/adapting cost and rest of the system costs more than going from 5hp to 50hp per side I just might go bigger. It might be less of a difference than power boosting the engine I mean to get to the same place if some common powerful usable motor is out there.

Experimenting with DIY hybrid ability is not out of the question either - actually it's part of the reason for considering this combo. I just wouldn't expect to experiment with that until later but with strong front motors i'd be mechanically ready just needing programming to make it work. If i'm considering an on-demand AWD 'stability control' adding hybrid is just some extra computer code and this WAS meant to be a bit of a testbed.


Can someone guesstimate how many thousands of dollars would be required to do this, including if using secondhand parts or unusual design (like a 5hp 8mph only "get unstuck" system with stepped/not totally variable throttle for a simplified power controller, and maybe even have to unlock the hubs once i'm on the road again because of how steeply it's geared) to drop the cost? I don't know my exact budget but it's something that if closer to $2000 becomes totally worth trying and as it creeps north of $5000 has rapidly decreasing interest. Some of it is for experimental/I doubt it would pay for itself in mpg savings, but there's a limit how much extra i'll pay to run those experiments I mean.