JD's 'new' Comuta-Car EV Project (1 of 2)

[oatnet]

I've been thinking about one since seeing one in my hometown in the 70's. so last week I bought a Shuttlecraft Galileo, er 1980 Sebring Vanguard Comuta-Car. TD, I'll be chasing you down for advice!

I have been wanting to leverage LiFePO4 in a lightweight EV project for a while - the lighter the better to minimize pack size. I have been thinking about converting a VW fiberglass kit-car as well or reconditioning a Citi/Commuta car, but most of the worthy examples have been too far away for me to consider - I think an electric car shipped cross-country is not very green.

This Comuta-Car was already titled/registered in my state and the owner was nearby and willing to deliver for free. This example has the sliding windows (the older ones were fixed but removable) but the seem stuck right now. It comes with the larger GE 6hp moter (vs 3.5hp), but it only has a 15 minute rating.

Although it only has 818 miles, it is pretty stripped and has been sitting for a while, so maybe $1,200 was too much. There are no batteries or controller. the tires are shot, I need to rework the brakes and I am skeptical about Dana differential until I fill it and see it in action. OTOH I planned on replacing tires/batteries/controller ANYHOW, and avoiding the hassles of re-titling a 30 year old electric car is worth a lot to me.

I expect to reduce the cars 1400lb weight by 1/3. AFAIK the Commuta cars came with (8) 6v lead-acid batteries that I estimate weighed in at @530 lbs. I will replace them with a 138lb, 6kwh, lifepo4 pack. I can put the LiFe under the seats, and eliminate the big Battery Buckets under the front/rear bumpers.

I think TD has reported 333wh/m on his Citicars, which would only give me a 14 mile range from this pack at 80% DOD. It would be nice if the 33% weight reduction decreases consumption enough to at least do my 16 mile work commute, although I dream of doing 150wh/m and get a 30 mile range! Maybe a diff rebuild and some aerodynamics will help.

-JD

View attachment citi_side_r_5374.JPG
View attachment citi_front_r_5373.JPG

 

[TylerDurden]

Nice!

If you are not a purist, major aero mods should make a significant difference. Most of the car could be highly modified and still qualify as street-legal in all 50, since you have an original VIN. (You may need more motor too, if you want to go highways.)

http://autos.groups.yahoo.com/group/C-Car/message/8978

Be forewarned: once you are on the road, you may be mobbed by question-askers and picture-takers; especially when gas gets pricey again.

 

[oatnet]

Nice!

If you are not a purist, major aero mods should make a significant difference. Most of the car could be highly modified and still qualify as street-legal in all 50, since you have an original VIN. (You may need more motor too, if you want to go highways.)

http://autos.groups.yahoo.com/group/C-Car/message/8978

Be forewarned: once you are on the road, you may be mobbed by question-askers and picture-takers; especially when gas gets pricey again.

Hi TD!

it hasn't left my garage uet but the question-askers you mention have already descended.

I would be a purist if it was fairly complete and original, but since the chassis is stripped I see it like a blank slate, ideal for my project. I am looking to prove that LiFePO4 can be cost-effective in electric cars, and the lightest car means the lightest, and cheapest, pack. AFAIK, this is as minimal a chassis as I can get for a factory-registered unrestricted electric car, in the most "potent" configuration with the 6hp motor with the Dana Transaxle.

My first target is to make it an effecient commuter that can easily keep up with 40-45mph traffic, simply by upgrading to lightweight modern power storage and control. I get cold sweats thinking about highway speeds on such a short wheelbase with with that plastic steering wheel, so I am not looking to push the top end. It would be nice to make it quick instead, albeit without catostrophic wheelies. 8)

I have a fantasy of bolting on a high-efficiency Mars BLDC and upgrading to an independant suspension. I also have a fantasy of stripping the ABS body, welding on some thin tubing in an aero shape, and covering the entire structure with mylar. I have a lot to do before I start thinking about tweaks though. Like, any idea where I can get a replacement for my glass rear hatch?

-JD

 

[oatnet]

TD, when you said you were getting 333wh/m @ 25mph, was that what you were putting into the batteries (kill-a-watt) or what you were getting back out of them (CycleAnalyst)? I was hoping for 150wh/m from the pack until I read your real-world experience and revised my expectations. However, I might have been comparing apples to oranges, so maybe my oriignal estimate will be accurate after all, that would be happy.

Have you rebuilt any of the diffs in your C-Car Fleet, any chance that they are leeching power? Are all of yours the Citi version?

-JD

 

[TylerDurden]

Hi JD,

The figures came from KAW readings for charging v. odometer readings. System is nominally 60V: 10 6V cheap golfcart batteries ~ 2yrs old.

Since the rear hatch is flat you can use acrylic or glass. The glass shops will prolly suggest laminated... it can be cut & drilled. Having a custom shape tempered is quite costly.

I haven't opened a diff yet, but I don't rekon there is much to them... IIRC, straight cut gears. Noisy. I suppose you could spin yours and measure just how much power it takes...

One citicar is running , the commutacar is wrecked but repairable.

Keep in mind, contactor-based motor control is immune to EMP attacks...

 

[oatnet]

Hi JD,

The figures came from KAW readings for charging v. odometer readings. System is nominally 60V: 10 6V cheap golfcart batteries ~ 2yrs old.

Since the rear hatch is flat you can use acrylic or glass. The glass shops will prolly suggest laminated... it can be cut & drilled. Having a custom shape tempered is quite costly.

I haven't opened a diff yet, but I don't rekon there is much to them... IIRC, straight cut gears. Noisy. I suppose you could spin yours and measure just how much power it takes...

One citicar is running , the commutacar is wrecked but repairable.

Keep in mind, contactor-based motor control is immune to EMP attacks...

The Dana-Spicer diff on the Comuta has heilical gears that should be a little quiter, gonna tackle it tomorrow. That spin test to measure wasted power is a great idea! Now that I know I don't need 333wh/m from battery, I can worry about rebuilding it for efficiency later.

I'll need to find/fabricate hardware for the hatch when I get to the cosmetics. Mine came with only bare mounts and cheap plexi screwed on. :x

 

[oatnet]

I got all 4 wheels off without snapping any of the rusty old bolts. One rim is the wrong offset,.I am waiting for 2 chevy monza 13x6 rims I hope will have the correct offset. I bid on some snazzy gold Cosworth Vega rims that should be the correct size, but they got pricy and I didn’t want people thinking “Austin Powers:Goldmember”

View attachment goldmember.jpg

It is hard to find tires for 13” rims, but TireRack.com carries Bridgestone Potenza RE92 165/65R13 that I am also waiting for, uncannily close to OEM diameter, and I have had great success with Bridgestones on performance ICEs so why not.

This year C-car has the Dana-Spicer Model 18 differential, which is purpose-built for electric motors up to 20hp, so it should stand up to overvolting the OEM 6hp 6.7” motor. To drain the differential, you actually have to pump oil out of the fill hole. Clean oil poured out the moment I opened the fill hole, so someone overfilled the diff for long term storage. I closed the fill hole and moved on to more pressing tasks, like the brakes.

The brake system was dry. On a whim I filled it, and although I managed to open all 4 bleeders without snapping them off I only got dribbling flow. I could have ordered a new one from a C-Car specialty shop for $85, but for 18.99 my local Kragen autoparts store carries Cardone Part number 10-1373 for a’75 AMC Pacer (and others) that was a direct fit. No thanks to the Comuta Car owner who posted to the c-car list that 10-1373 didn’t work - it does, here is a pic:

View attachment brake master 5419.JPG

WD40 and I got the old master off without stripping or snapping the bolts and brake lines. I bench-bled the new master, fitted it neatly in place – and still dribbling, the rubber lines are probably swollen shut so I’ll go order new ones, but right now I am dedicated to my other EV project, the VW Bus conversion: http://www.endless-sphere.com/forums/viewtopic.php?f=7&t=8012


In the meantime, the new batteries are here! I’m going to post a thread on the pack on the battery forum and link here. I want to get to 72v, but will start at OEM 48v so when I go to compare WH/M and acceleration, the only difference will be dramatic weight savings from LiFePO4 and a modern controller. If I want more speed, acceleration, or range I’ll increase the voltage with more cells in series.

 

[oatnet]

Sadly, the Monza wheels have the correct offset, but the lightweight forged aluminum is way too thick for the lugs. I got a vega GT steel wheel to replace the bad rim, and I'll just use ugly wheels for now. I'm going to try to get the tires mounted today.

I got stainless steel M6 set screws from Amaon that I will use to join the cells end-to-end in series. I wanted 15mm but the longest they had was 12mm, hope that is long enough to sandwich the copper-strip I am using to parallel the cells and land the charger leads.

Lots of the Citicar folk recommended replacing 29 year old motor brushes - even though they only have 850 miles - and I will bow to experience so I bought some. I absolutely needed new brake lines, and the ONLY place I could find them was at http://www.evperformance.com/c-1-brake-components.aspx . They also claim to have a special version of the motor brushes that the Comuta needs, allegedly different from the standard golf-cart brushes. I would have purchased more items from them, but there prices are 4x-6x more than I see elsewhere, so I only purchased what I absolutely couldn't find elsewhere. I ordered it on 12/26, it didn't ship until 1/5, and I got the parts on 1/9. When I called in for status I was told someone would get back to me, but they never did. Here are those parts:

View attachment Motor brushes and brake lines - 5607.JPG

 

[TylerDurden]

I use cheep 13" trailer wheels on my cars. Trailer tires are often lame but you can sell em and get car tires.

 

[oatnet]

I use cheep 13" trailer wheels on my cars. Trailer tires are often lame but you can sell em and get car tires.

A lot of owners reported significant handling improvement by going from the stock trailer tires to radials, and I want it to be as safe as possible when I bump up to 72v. Car tires are a bit much for the 4" trailer rims it came with, so ultimately I'd like to find 1-3 more of these 6" Vega GT rims and paint them gloss white to match the car.

I bought a set of Bridgestone Potenza RE92 165/65R13 from tirerack.com for $63 each and $56 shipping, and it cost $40 to have them mounted/balanced locally. There were 2 slightly cheaper tire choices, but this was within a whisker of OEM diameter with significantly larger contact patch, and I have had a lot of success with Bridgstones on my ICE's.

Now to get the brake lines going so I can start sorting the mess that is the drum brake spiders.

-JD

 

[oatnet]

Assorted brake line replacement projects. No point in making it go if I can't make it stop.





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EDIT 12/12/12: replaced pictures lost when the forum crashed a few years ago.

 

[TylerDurden]

FWIW, PB-Blaster is a much better penetrant than WD40 (IMO). I will sometimes soak joints for a day or more.

A mini-torch to heat the coupling will also help, if you keep the flammable stuff away.

 

[Ypedal]

+2 on the PB blaster.. i love that stuff ( and yes.. it kinda smells like peanut butter ) :wink:

 

[deanoseadog]

Man I wish we got those C-cars here in Aus!
Improving efficiency is nice and stuff, but I rekon get the biggest D&D motor that fits in there, and 120V of Lifepo4's! WoooHoo! That would be cool! Then if you get time, you could put some of those fancy "disc brakes" on it or maybe even a rack & pinion steering setup.....have they even got any dampers standard? Or are they just a bunch of leaf springs?

Keep the updates coming.

 

[Roy Von Rogers]

Man I wish we got those C-cars here in Aus!
Improving efficiency is nice and stuff, but I rekon get the biggest D&D motor that fits in there, and 120V of Lifepo4's! WoooHoo! That would be cool! Then if you get time, you could put some of those fancy "disc brakes" on it or maybe even a rack & pinion steering setup.....have they even got any dampers standard? Or are they just a bunch of leaf springs?

Keep the updates coming.

I started as an automotive tech in the early sixties, and found a little secret along the way for getting rusted bolts and nuts off. Actually found it by accident working under my wifes 73 Nova, trying to remove the exhaust pipe off the manifold. Anyone whos ever done that knows how though it can be to remove those, not to mention braking one off in the process.

The manifold nut wouldnt budge, so I'm laying under the car looking for something, and spotted a can of carburator cleaner spray near me, I said "wth its wet" and sprayed it on the stud and crabbed my long extension with the ratched, expecting to have to get out from underneat and get some heat to get the nut off. I was totally amazed how easy the nut came off and been using that stuff on rusted bolt/nuts ever since.

Next time you have a rusted bolt/nut, try it, it will amaze you.

Roy

 

[oatnet]

What a great car!

 

[voicecoils]

I think an electric car shipped cross-country is not very green.

pret auto

Think life-cycle


@ JD

Good luck with the sale

 

[julesa]

LOL @ "Shuttlecraft Galileo." Maybe you should weld some nacelles onto the sides. :lol:

 

[oatnet]

Updated pics:

Now that it is on the new tires/rims, I was amazed that I could move this around easily with one arm, it is truly a lightweight project.

-JD

 

[oatnet]

The comuta has moved on to a really cool new owner.

He built this amphibious geo metro that does 60mph on the highway and 30mph on the waterway. Here is a video, it is really impressive to see this baby plane and take off:

EDIT: Not sure what is wrong with my youtube imbedding, here is a link to the vid:
http://www.youtube.com/v/HabVkoW2T_8
[youtube]HabVkoW2T_8[/youtube]


Jon already has a citicar with just the rollcage (abs body removed), but he ran into a group of folks converting 5hp Briggs & Stratton motors into compressed-air driven motors. He has a river tours/dives business so he has plenty of compressed air, so he is putting one of these motors into his citicar to use it as a submersible. The tank that drives the motor will also supply him with breathing air.

Frankly, if I heard that plan from anyone else, I would fit them up with a tin foil Fedora - but that video above shows Vision and project execution, so I not only expect it get finished, I expect it to be cool and be incredibly functional.

Jon drove a long way to pick up the Comuta, far enough for me to break my Golden rule, we negotiated a price up in email instead of waiting until the cash and product were ready to be exchanged, I knocked off $200 to sell at $1400, a $800-$900 less than I had into it and a screaming good deal. He was a good buyer, and did not attempt to reopen negotiations.

I sent a bunch of measurements to make sure it would fit in the back of the truck. Jon could have brought a trailer but didn't want to be forced to do 55mph (CA trailer law apparently) on the way home, and have the extra drag/gas $$$. Because of the long drive (600+ miles round trip) he wanted to meet mid-day. I was able to come home from work at lunch to do it, but that meant we had to do the deal FAST so I could get back.

Jon showed up early and had the ramps ready when we arrived. He did a quick checkout of the comuta, and settled right into the title/cash exchange. He tried to winch the Comuta up the ramps, but the winch was secured by ropes that snapped, so we pushed it up the ramp - and it took my wife pitching in for us to make it up there. The Comuta took up a ton of space in the garage, but fit so handily in the back of the pickup, that my wife said "It looks so much smaller when it is outside". I have heard that before, but not about the Comuta.

I grabbed the last few photos (below) before I headed out to work - I wonder how much downforce he got from the comuta windshield at 85mph on the freeway. :lol: Anyhow, Jon was a great buyer who lived up to his promises and bent over backwards to make the deal happen, I would recommend him to anyone!

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View attachment 3

pvorlicek is local and came out to see it, but he thought the build was more than he could handle. Preston and I have bought stuff from each other and he has always been great to work with. I was disappointed because I wanted to see it grow up nearby, and I think he didn't give himself enough credit, but it doesn't make sense to start a project that intimidates you it makes it less fun.

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I've been riding my Vectrix so I haven't driven my s2000 since June, plus it has been buried in EV flotsam above that would have made it difficult to dig out. With the comuta gone, I can now ride my s2000, my Vectrix, or my current favorite ebike, without moving a damn thing. AAaaaaahhhhhhh.

Oh, and my wife can fit her car in the garage again now. That makes my life easier too.

-JD