David, Thanks for your detailed and thoughtful analysis! I *think* I'm dodging most of the worst pitfalls you caution against. Specifically:
> The result is that your hybrid isn't going to be optimized as either an ICEV > or an EV. It's likely that its EV range will be less than a similar BEV's, > and its fuel efficiency less than a similar ICEV's. It's a very safe bet that you're spot on...but, as wonderful as fuel economy is, that's actually something that I think is reasonably quite far down the list on this particular project. The EV's efficiency is most important in terms of range and battery pack size (and therefore cost, volume, weight, etc.) and secondarily in terms of cents per mile. The ICEV's efficiency is pretty much all about cents per mile. For this project, I'm really only looking for a battery pack big enough for local trips; a couple dozen miles would be plenty. I suspect that the smallest pack that puts out the necessary voltage is going to be just about the right size, even with those batteries having to lug around all the extra weight of the combustion engine and transmission and fuel and the like. And, even if it's right on the edge of being enough for some particular trip, having to use the combustion engine for the last mile or two of a twenty-mile trip really isn't a big deal. So, for practical reasons, electric economy isn't (much of) a concern. For financial reasons...well, I'm already generating so much surplus electricity from my solar roof that the electricity for the vehicle is going to be free, pretty much regardless -- and, again, even if I have to buy the last couple kWh or so from the utility, that's again a rounding error. The combustion engine's efficiency when working alone will certainly suffer, both from the added weight of the electric motor system and from having to spin them. However, I don't anticipate ever wanting to use only the combustion engine in isolation (save for emergencies). Rather, I'd use the electric motor as a "traditional" Prius-style hybrid, for acceleration and regenerative braking; that alone should significantly more than make up for any losses introduced into the system. Will it be as efficient as a new car, especially a new hybrid? Not even close. But it'll be a lot more efficient than a classic Mustang, and the total efficiency (when considering all-electric driving) will be so insanely more efficient that, again, the fact that it doesn't do so great in an absolute sense in certain limited situations isn't going to be worth worrying about. > From what I can see, it's (not surprisingly) any hybrid is tougher and more > expensive than a straight BEV conversion. I think this is especially true > of a parallel hybrid, because you have somewhat less flexibility in > positioning components. This has certainly been a big challenge in getting to this point. The initial thought was something mounted in place of the generator, then something mounted to the front of the crankshaft. But I *think* it's (potentially) solved with the direct-drive configuration. Even if the tunnel has to be enlarged a bit, there's about 50" of driveshaft in the car that's nothing but a spinning rod. Replacing a passive linkage with something that provides power makes a lot of sense to me, and there's the physical room to fit it in. That still leaves the question of where to put the controllers and the batteries, but I'm less concerned about that. The controllers aren't all that big, and likely would even fit under a seat. The batteries would need more room...but I don't think the battery pack is going to be much larger than a banker's box, and I can certainly spare that much volume from the trunk. > (One possibly more flexible parallel hybrid variant > is the "through the road" hybrid, where you drive the front wheels with one > fuel and the rear wheels with another.) I've investigated this, too. Using HPEVS- or NetGain-style motors to provide power to the front wheels...I just don't see that happening. That leaves hub wheel motors, and all the ones I've found that are readily available (and not solely the plaything of a research lab somewhere) aren't anywhere near powerful enough for a car the weight of a Mustang. If I'm mistraken on that and there really are hub wheel motors available that would work, that would be a *very* attractive option to consider. But a pair such wheels would have to be at least as powerful as an AC-35 or Warp 9, and I've not found such a beast. > To get a final result that's as efficient and as seamless as one where a > team of automotive engineers designed it (Volt or Plug-in Prius), you > probably need to have some automotive engineer chops yourself. Agreed -- and, fortunately, I'm not looking for something with the efficiency or engineering elegance of those cars, and I don't mind throwing a bit of brute force at the job (such as a pair of AC-50s) in lieu of sophistication. > Just remember that you have to provide all the patches that you'd have to do > in a BEV - power brake vacuum, power steering pressure, and aircon drive. > You need a DC:DC converter (or, somewhat cruder and less efficient, a motor- > driven alternator) to provide 12v house power. You need an electric heat > source for cold weather driving. (It occurs to me that in a homebrew hybrid > you might be able to dispense with some or all of those items burdening the > ICE. Just remember that the energy to run them has to come from somewhere.) Fortunately, electronics simply didn't exist in 1964. The car actually has a generator, not an alternator, and the current fuel pump is mechanical. The breaks and steering are fully mechanical. I'm pretty sure I'll have to *add* electronics to the car to get it to work ideally, such as an electric fuel pump and / or injection system so the EV motor controller can shut off the combustion motor when it's doing nothing. The whole question of climate control is still one that's up in the air for me, especially since I'm wondering if there's any way to tie that in with keeping the batteries happy during the Arizona summer. Heating generally isn't a concern, and I could probably live without it if absolutely necessary. It'd be really nice to have air conditioning for the cabin, but that's not an absolute requirement. I'm pretty sure, though, that *some* sort of cooling is going to be necessary for the electric motor and its components, and I wouldn't at all be surprised if cooling turned out to be a significant limiting factor of real-world performance. > Kits aside, if you're a good hacker (in the positive sense) with lots of > spare time, a machine shop and the expertise to use it at your disposal, and > nice deep pockets, what you describe would be a fascinating project. My pockets aren't limitless, but I'm hoping that the money I'd otherwise save on batteries will go a good part of the distance...and I have a shade-tree mechanic who doesn't charge nearly what he should who's a real artist when it comes to improvising and fabricating stuff. Thanks again for the input...it makes me think that I *might* still be able to pull this off.... b& -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 801 bytes Desc: Message signed with OpenPGP using GPGMail URL: <http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20140721/894d6d0f/attachment.pgp> _______________________________________________ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
