Introducing myself - eejit with an electric car project

PostPost by: Own Little World » Sat Nov 07, 2015 5:53 pm

Also, on the purism front, the car I have didn't come with an engine or petrol tank or Elan gearbox. Even if I could source all of these it would never actually BE original. The closest it would come, with a good wind, is LIKE an original in some regards.

It also has 4 minilite replicas and needs a rear bumper etc. etc.

I can sleep at night bringing it back to life and burning fewer hydrocarbons in the process.
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PostPost by: Bombay Racing Green » Sat Nov 07, 2015 9:34 pm

Hi Alec,

If you go to www.thunderstruck-ev.com/ac-motor-kits/ ... 51-ev.html it quite handily has the charts for each motor/controller option. One option has the torque going flat out to 2500 rpm and another goes out to 4500 rpm. 144v is what I was looking at.

If you look at some of the EV4U tutorials the chap uses a rough rule of thumb for range calculation. I've just dug it out. Here goes:
Weight(lbs)/10= watt hours/mile

Pack size = (battery voltage x amp hour rating) x number of cells.

NB Only 80% is useable.

Range = pack size divided by watt hour/mile

For example:

2500lbs/10 = 250 watt hours/mile

Most lithium batteries are 3.2 volts. 3.2v x 44 batteries = 140.8 Volts. Hence the 144 system voltage.

Pack size = (3.2 x 180ah) x 44 = 25344kwh x 0.80 = 20275kwh useable pack size.

Range = 20275/250= 81.1 miles.

Apologies if the units are incorrect.

Later he does real world test runs to see what range he gets. It actually comes quite close to the calculation. The tutorials go into conversions of a Karmen Ghia, VW type 25 crew cab van and a Porsche. They will give you some good ideas about battery pack placement. I was thinking along similar lines to yourself in that regard. An EVTV programme goes into some of the newer batteries which are smaller in size (and capacity) but they are much easier to get into awkward shaped spaces. It shows comparisons between an older conversion of a yellow VW Thing and a newer Yellow one.

I'd certainly recommend having a look at some other conversions. There are a lot of mx-5/Miata conversions which may give you some similar results as a +2. Bear with the EVTV programmes, they are over an hour long in many cases! The EV4U ones range between 15-45 minutes. The Ghia conversion would be quite pertinent for our projects.

Hope it helps,

Pete
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PostPost by: Own Little World » Sun Nov 08, 2015 10:22 am

Hi again Pete,

I have been looking again at the controllers to find the source of my confusion and see now that it was the Scott Drive controller that is recommended for AC and brushless DC. It is also red, which is probably it!. However, it is too small. It looks as if the Curtis 1239-8501 is the best option.

On the motor front, the AC-76 is about $800 more for only a couple of extra horses, which may equate to a couple of extra mph and half a second 0-60 than the AC-51. Only marginal.

Do you know of any other AC options out there?

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PostPost by: JJDraper » Sun Nov 08, 2015 11:39 am

I had these thoughts once.. Probably cheaper than sourcing and a full rebuild of a Twinc!

elan-mods-f31/and-you-thought-zetec-was-heresy-t31908.html#p213785

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PostPost by: Bombay Racing Green » Sun Nov 08, 2015 3:59 pm

Good afternoon Alec,

Siemens seem to produce some good motors but for ease of purchase and installation a complete HPEV/Curtis solution is more practical. Is the AC 75 a lot larger than the 50/51? It may cut down on the number of cells that can be placed in the front.

I was thinking of mounting the controllers etc. on a heatsink mounted in place of the radiator. Obviously the covered electrics would be mounted on the aft side and therefore out of direct water. This might do away with the need for a pumped liquid chill plate. I am based in Ireland so am not expecting Southern California heat waves.

Someone has actually done an electric conversion of a Europa. If you do a Google search you will find it. It used a DC motor and lead acid batteries. The range was around 30 miles I seem to recall. It looked very nice.

I suspect this thread will be moved in time to the mods section but if you want to chat privately then just give me a PM. What names are you thinking of? eLan? +zEro?!

Regards,

Pete
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PostPost by: Own Little World » Sun Nov 08, 2015 4:53 pm

Hi Jeremy - yes cheaper and maybe simpler too. Certainly easier to maintain afterwards...

Pete, I think the AC-76 is about 3" longer and about 1/2" bigger in diameter, so apart from the price it is unlikely to make all that much difference.

I was thinking that for aerodynamics I would block up the radiator intake and put an aluminium belly pan under the engine bay. That would hopefully give a teeny bit more of a crumple zone between bumper and chassis (another thread to come on that subject) but also help keep the batteries away from winter gales (even the South Coast of England is not California either). Some components that need chilling could maybe have heatsinks mounted on the belly pan with the fins facing down and oriented front-to-back for aerodynamics. However, this planning is still in its infancy.

I think I saw something about that Europa somewhere. I'll have another look.
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PostPost by: Bombay Racing Green » Sun Nov 08, 2015 5:13 pm

Hi Alec,

I've just had a look at the AC-76. It certainly looks impressive in terms of torque output out to 4000 rpm. It will give you better overtaking performance. Nice choice.

In terms of authenticity, I think this is a neat way of breathing new life into some abandoned +2 projects. There always seems to be either a +2 or S2/TC Europa that has been relieved of its engine and other valuable parts then put on eBay.

All the best,

Pete
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PostPost by: Own Little World » Mon Nov 09, 2015 8:39 pm

Yes, overtaking torque would be welcome (especially wearing a Lotus badge). I have had loads of fun for years in my B with great low end torque, leaving people standing at the lights. However, the acceleration at 60 mph and above lets you down somewhat. It would be a shame to suffer the same in an Elan.

Many of the rule of thumb range calcs in the EV4U vids are in the same ball park as my own, which is encouraging. The 100 mile barrier (not to mention the 150 mile goal) is going to prove to be a challenge, which will probably come down to shedding all creature comforts or a breakthrough in battery chemistry, or both.
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PostPost by: jimj » Mon Nov 09, 2015 11:32 pm

"I have had loads of fun for years in my B with great low end torque, leaving people standing at the lights." ??? Really?
It`s more fun in a Lotus peering down from the moral high ground, with a look of disdain, obviously, and not bothering, with nothing to prove.
Fit a twincam and a fuel tank, add value and save money and you`ll have a really nice car..........but I know that`s not such an interesting challenge. Good luck.
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PostPost by: stevebroad » Mon Nov 09, 2015 11:59 pm

If I was starting my project now it would be either a V8 bike engine or electric
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PostPost by: The Veg » Wed Nov 18, 2015 4:05 am

[quote="Own Little World?]The Ferrari sounds very interesting - the 308 was fiberglass too, wasn't it?[/quote]

Only the earliest ones. Not long into the first year of production they went to metal.
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PostPost by: yvesmontreal » Mon Feb 01, 2016 1:07 am

Welcome. This is an interesting project, and I'm sure we'll see more and more of those in the upcoming years.

When I'm not playing with old sports cars, I work with transit buses - and a lot of action is underway to develop electric buses. I'm following very closely, and I like to remind people that powering a road going vehicle with an electric motor has never been an issue. The first car that broke the 100km/h barrier was electric (1899). The issue has always been and still is to go far. Batteries still do not have a high enough energy density to make electric conversions easy.

I once met a fellow who had electrified a VW Rabbit pickup truck (a US oddity); a forklift DC motor was mated to the 5 speed gearbox thorough the clutch. The bed was filled with 8D lead acid truck batteries. He ran the thing at the drag strip; it would run the 1/4 mile below 16 sec. He used an ammeter as a tach; flooring the "throttle" in first gear he would get a high amp rating, and would shift to second as the amps went down, and so on.

I wonder if "current" battery technology is really compatible with lightness. To get decent autonomy you need to load the thing with batteries; you need space and load capacity. Getting enough power to move this weight is not as much of an issue; unless you're climbing a lot of hills, once underway weight has only a minor impact on rolling resistance. In short, I wonder if it wouldn't be easier to start with a bigger/heavier car than an Elan.

This said, there is currently a basket case Sabra Sports on the local market. Guess what crossed my mind...
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PostPost by: The Veg » Mon Feb 01, 2016 2:30 am

yvesmontreal wrote:I wonder if "current" battery technology is really compatible with lightness. To get decent autonomy you need to load the thing with batteries; you need space and load capacity. Getting enough power to move this weight is not as much of an issue; unless you're climbing a lot of hills, once underway weight has only a minor impact on rolling resistance. In short, I wonder if it wouldn't be easier to start with a bigger/heavier car than an Elan.


Maybe just wait for this to come along?

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:mrgreen:
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PostPost by: yvesmontreal » Mon Feb 01, 2016 3:28 am

That's what I was saying... this works on a much larger car. Even if it has a Lotus influence. But it's on the market somewhere... this scene was back from 2015.
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PostPost by: john.p.clegg » Mon Feb 01, 2016 7:37 am

...no where near April ,yet.

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