Asking Slashdot: Converting an SUV Into an Hybrid Diesel-Electric? 543
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timothy
from the confuse-both-sides-of-the-spectrum dept.
from the confuse-both-sides-of-the-spectrum dept.
joaommp writes "So, my team has started a project to convert an SUV into an hybrid diesel-electric vehicle — basically, an electric vehicle with a diesel engine working as a range extender. We've now setup a campaign on Indiegogo to help with the project costs (we are a non-profit team) and later we'd like to, if the project is successful, be able to provide conversion kits and additional kits for elements of the transformation, like the HUD, for example. Why an SUV conversion? Because a lot of people like SUVs (sense of safety, overcompensation, etc) but they're un-economic and environment unfriendly. I'd like to ask all slashdotters if they have any advice or tips for this project. We already have the project well defined but more input is greatly appreciated before we begin tearing apart the beast. So, if you could help providing additional advice and information, it would be awesome."
do NOT start from an SUV. start from a smaller car (Score:5, Interesting)
ok: i've been working on designs for hybrid electric vehicles for some time; i have a 1st prototype project underway at about 30% completion, and am planning the 2nd and 3rd vehicles already. the 2nd and 3rd vehicles will be a saloon and an SUV, respectively, but critically they will be *from the ground up custom built*. there will *NOT* be a *SINGLE* piece of the original chassis used.
why is that? well, it's very simple: they're far too heavy. you're starting from a 2,000kg vehicle where all the parts are designed to transport a 2,000kg vehicle. google "mass decompounding", and you'll find out more about the concept. look up how much fuel is needed *just* to overcome rolling resistance because of the heavier vehicle. it's absolutely insane.
unfortunately, as i've just found out from the 1st prototype, even if you use a 750kg vehicle (a suzuki swift aka "geo metro" in the US), the weight of the four wheels, their brakes and the steering assembly are all a significant fraction of the target weight of 350kg.
so i have instead been looking around for "quad bike cars" - aka "microcars" as donor vehicles. the parts on those are *much* more suited for use in a hybrid electric vehicle. apart from anything, you will *automatically* get better fuel economy simply because of the lower weight.
so what i recommend that you do is to get one of those "microcars", chuck away all the plastic (or fibreglass) bodywork, and then make your own (large) geodesic bodywork *from scratch*, and cover the entire thing with either canvas or dacron (sail cloth). there's a web site online about a guy who makes single-person canoes weighing *less* than a carbon fibre one, out of dacron and a wooden geodesic frame strengthened diagonally with kevlar strips. pure genius.
and because you're making the bodywork from scratch, it'll be possible for you to literally make the vehicle as large as you like. and, because it's made of 1mm or 1.2mm tubular steel in a geodesic frame, it's easy to make (and repair), it's strong, and it's light-weight.
regarding the powertrain: i too originally was going to go for a series hybrid powertrain. but then it occurred to me that that is ridiculous. you have a 240v AC generator comprising a diesel motor and a generator. then you have some quite expensive electronics to convert 240v AC mains down to the DC voltage for charging the batteries. then you have a motor controller, which is also expensive, and then you have *another* electric motor! oh, and then a gearbox.
so the drivetrain i finally settled on (for the 2nd and 3rd prototypes) is a parallel hybrid, out of nothing more than a diesel engine, a clutch, a CVT gearbox (from the donor microcar) and an electric motor. the diesel motor will be connected to a double-ended output shaft from the electric motor, via a clutch. there will be *no* starter-motor (again, saving weight) because you simply disengage the clutch, effectively using what most people call a "push start", and the diesel will kick in. it'll need a bit of computer-control to compensate for the back-lash from the clutch, but that's just software.
this rather crude lash-up is all that distinguishes a series hybrid from a parallel one, but it saves enormously on both the overall cost (measured in thousands of dollars) as well as the weight, which again translates into a cost saving due to not having to lug vast lumps of metal around.
the message should therefore be coming through loud and clear. don't for fuck's sake start from a pre-existing SUV. if you've bought one already, do the planet a favour and scrap it, because there's nothing on the vehicle that is of any use to you in achieving anything *remotely* resembling a fuel-efficiency saving or carbon emissions reductions. if you don't follow my advice, you will find out *why* you should have listened, which is probably a much better lesson for you. i won't say that you will have wasted everyone's money on indiegogo, because you won't have: they too will have learned an incredi
Re:Use a Lupo engine (Score:5, Interesting)