Need E-truck concept advice - newbie

So - I'm having great fun with little PM motors and making scooters and go-carts for the kids. I'm trying to hit 50 on "mine" with six Chinese 250W motors, twelve SLAs, an AllTrax controller, and a simple fairing.

Anyway - I have a great personal app. for an electric vehicle for me, for two years usage, starting in August. For various reasons, I want to slam my rusty old truck I've had for twenty years (my daily driver), leave the outside with all its patina, make a beautiful interior, and electrify it. Here are the parameters:



I'm a professional mechanical engineer with a good home shop;TiG & MiG, oscilliscope, mill access, etc.

Truck is ~3000# without engine and trans, has full ladder frame.
For style reasons, it will have to have a narrowed rear axle and wide tires - 33" diameter.
Aero - no rack, lowered 5-8", front air dam, no side mirrors, tonneau cover, flush wheel discs of rusty steel.
I'd like to rotate the rear axle 90° (pinion shaft pointing up), and mount a used forklift motor directly.
Forklift batteries for now - I can get a deal.

Mileage is exactly 90 miles per day, 5 days a week, 40 weeks/year
95% Interstate driving, little traffic, flat-ish terrain (Madison - Conyers, GA on I-20)
Needs to achieve 75 mph; maybe cruise at 70 (the speed limit)
3000-3500 motor rpm will work with the axle ratio I have now (could easily change)
Sequence is 75 miles in the morning, then 15 miles in the evening - work will allow me to day-charge
It must be able to spin the rear tires from rest - goofy, but required for the street cred
Will have seat heaters
Will have a 5000 BTU window AC unit thru the "firewall" at the old transmission hump

Seems like I need 20-30KW cruise; 30-80 acceleration; ~110 mile range

So - 40-50 KWH pack capacity? Less, and part-charge at work?

Goal is a fun learning project, to shock people, and spend $10-15K max.
Could be lithium later, as we get into them at work.

One alternative is buying that bright green 2011 Ford Fiesta - fun, but not cool.
The other is to still slam the truck, and put in an 8.2 liter Cadillac drivetrain in I have.
Cheap to do, and super-cool, but Cro-Magnon and no mpg at all.

Help me ball-park this - all comments welcomed!

Forrest - in Atlanta

Here are some "visual cues" for which I'm shooting -



Forrest

Sounds interesting. For best rear tire spin without using as much power to do it, you will want to avoid lead-based batteries, especially since the best place to put them is in teh ladder frame, most of the space of which is in the rear past the axle. Also, putting as much of the weight forward as possible will help, especially since taking out the engine is going to make it rear-heavy, with the electric motor not likely to be as heavy as the ICE.

If you can afford it, Headway or Thundersky or CALB/SE would be decent choices; they have been used successfully in lots of conversions.

If you look thru EVAlbum you can find at least a few conversions of similar vehicles. At DIY Electric Car forums there are a few different threads that contain build logs of vehicles that have various parts you can emulate for yours, such as battery boxes in the ladder frame, traction-breaking torque, etc. Those might give you good starting points to work from, since there's not much on ES like what you want, yet.

Are you going to go for airshocks that will let you raise/lower the truck for different situations?

McDesign said:

The other is to still slam the truck, and put in an 8.2 liter Cadillac drivetrain in I have.
Cheap to do, and super-cool, but Cro-Magnon and no mpg at all.

Click to expand...

This option gets my vote, Airbag it and drop the the biggest nastiest fuel sucking V8 you can get
in it...

KiM

I sort of already have that kind of toy as my "weekend car" (5.7 Chevy now) -



And a 500 inch Eldorado drivetrain for the "upgrade" -



Forrest

^^^^ Oh hell yes thats what i'm talkin' bout
I gather shes a kit car replica but unsure of the 'model'
Looks like it has a prancing horse badge but i dont
recognize it as a Ferrari?

KiM

It's a '78 Mid-Engineering Kelmark - with mucho personal mods. Something I had wanted since Car & Driver did an article in High School in 1979 -

\
View attachment 1

http://www.youtube.com/watch?v=65Jt3K3SU9Y

Forrest

I rekon about 2.5 tons in PbA.

I'm hoping under 4000lbs for motor and batts, from looking at forklift battery suppliers. I need to know the best voltage to run the motor, so as to pick the NUMBER of batteries.

The good thing is that the truck is fine with that weight. I've always had air "helper" springs, and often driven it loaded to the dump at just over 8000 lbs. Cutting the front springs will stiffen them 15-20%, and a front-biased weight distribution is normal for pickups (ands easier to spin the tires).


Forrest

I was going by the Trojan t105 specs: 6V 225AH, 62lbs. Divide by 2 for peukert & DoD.

"I'd like to rotate the rear axle 90° (pinion shaft pointing up) "
You know, that makes me wonder, whats going on in there to get oil up to the pinion bearings....

If this was a lighter S-10 sized truck (especially if you only needed a non-highway 50-MPH max), there have been several e-conversions on the web with detailed pics and info using a motor directly spinning the driveshaft. Since this is a pretty heavy beast (I've had a couple of these) I would seriously consider finding a junkyard manual transmission.

I don't know what the best gear ratios would be, but you will likely only need two of the gears, and hopefully you could find a cheap 3-speed with acceptable gears.

Having two gears available would lower the over-all amp-draw, and that will help in several areas. The size/price of the controller, size/price of switches/copper-cable, several factors concerning the battery pack, etc...

If geared/volted for 70-MPH and being direct drive, you will have "X" amp-draw at low speed during acceleration. Raising the pack volts as much as possible, and adding 2 gears will help lower peak amps.

You might consider putting 1/3rd of the batteries in the engine compartment, and 2/3rds in the bed, just behind the cab. That seems to be pretty common with truck conversions. Best of luck!

You need to find a new painter for those windows !

This looks like a good project. Here are a couple of links that should inspire you. These guys provide detailed, step by step, reports on their conversion progress and provide the theory & calculations needed to plan for motor, controller, gearing and battery sizing. They are converting full size cars with the goal of duplicating or improving original performance and not compromising anything. Some of you guys may already be familiar with Victor & Bob's work, but for those who are not....

http://www.metricmind.com/

http://www.evdrive.com/BMW_project/ProjectBMW.html

Wow - I devoured that for hours last night. There's a lot to get my head around - luckily I've got a fairly simple and well-defined target, and it's SUPPOSED to look sorta' like a hack.

Forrest

double down on the windows. just reorienting your priorities to the windows will maybe stop you before you dig this hole deeper.

Hillhater said:

You need to find a new painter for those windows !

Click to expand...

LOL! I AM a good painter , gosh-darn-it, and people LIKE me! - here's a look at the part of the house visible out that window, taken last weekend.



Forrest

maybe instead of a 6 ton vehicle which will be mostly immobile anyway, pour 6 yards of concrete in front on the street to make a pad for a neighborhood electric vehicle charging spot.

it is always a delight to see the quality of work people once did. and how cheap it can be now. 1907?

Let's see - the front part of the house is 1886; part of the back and the rear 2nd story from 1915. The octagonal bay I added about fifteen years ago. When I grew up down the street, it was the run-down house where the mean old sister ladies lived. They were born there in 1907 and 1910, IIRC. It was a boarding house for the college down the street (became Emory University) from 1886 to 1917, when the college moved to Atlanta - we've got lots of cool (preserved) graffiti carved into the mantles (an even dozen of them) with hot pokers.

As far as the truck, it's more a project to have fun and get my hands wet as much as anything else - I mean, I will try to use it as a commuter vehicle for those two years that I need it. Here at work, the emergency group is starting to explore battery packs with Lithium in general and 123 cells in particular. In a year or so, I may have access to as many of them as I do to SLAs and NiCads now - I want to be ready!

Forrest

to get ready, watch for '84-87 CRX with blown motor for a chassis with trannie after you strip the motor exhaust and gas tank (1500lbs).

the 6 tons of concrete will be more useful than the 6 tons of truck full of lead acid. the springs have lost a lot of punch already imo, so it will be a low rider by default.

i really think creating charging spots is more valuable than building more old technology EVs. maybe in 5-10 years you can find a used leaf or iMEV waiting for a new set of batteries so it would be the deal then.

i do like old houses, i could see 3 chimneys, all still intact, that is impressive, so 12 fireplaces is not surprising. usually they would add propane heaters in the fireplace which would be covered to cut the heat loss, vented through the chimney. all classic. sweet digs.

maybe 3 yards of concrete would get you to a 20'x16' slab 2.7-3" thick with some rebar or 6x6 mesh, just don't ask for an inspection from your local building dept. run a double loop of 12G romex out there, you will be so far ahead of the game, especially there.

I think it 'may' be a false savings to use a truck you already have, of the type that is somewhat outside-the-norm for successful builds. You save money by not having to buy a truck for this project, but the cost of the amount of battery you need to get barely acceptable performance will hurt the budget. The truck that you use should last years, the expensive batteries will wear out and have to be replaced.

If the large gasoline truck runs OK, you might be able to sell it for $1000-ish, and then find a more appropriate vehicle for that same $1000. I would look for a Chevy S-10 (unless you have strong preferences for something else) that has a fried motor and a manual transmission. You might even get that for even cheaper since it has a fried engine.

Saving 1,000 lbs right in the beginning will help everything, cost, speed, range, braking. I wish you the best of luck with whatever you choose...

Just for street cred, here's the same view of the rear of the house right after we got it, in 1992 - it had been vacant since 1978.



Forrest

Wow, nice job on the house! I love a good house renovation.

nobody dissing your 'street cred'. mine was built in 1924, had been vacant 2 years when we bot it in 1980. somebody did a lot of nice brick work, chimneys and footings. that red sandstone is similar to what they take from the lyons formation where i live in colorado. the sandstone slabs were broken out and shipped east to make sidewalks before concrete became so cheap in the late 19th century.

think 100 years from now. concrete which now costs $100/yd will cost over $1000/yd as the price of fuel to make clinkers follows the price of energy so the best investment now is in the things that seem like they are of little value now.

of course it does not help that copper has made this huge run, it is not going back so gotta bite the bullet now, build the charging spot, and they will come.

gas will be over $4 this year, crude will close over $137 this year, never going back. expect ready mix to be $140/yd as the economy recovers too.

you can see where they added on the bathroom on the left as sewers were introduced in the 20s. steel pipe vent.

go for gutters, you guys don't have basements there do you? i poured sidewalks around the entire perimeter of mine to keep water from ever getting into the basement again, it all drains to the back yard now. 12 year project that was capped off by my own neighborhood EV charging spot in my driveway apron. BOL, go lite. 84-87 CRX with blown motors are $250-400 in straight condition, and very common if you watch for them on CL or do people use CL down there?

CL is definitely used! Got a buddy with a nice red electric rabbit cabrio, been in the paper; been in parades. Nice, but like a CRX, just exactly what people expect for an electric conversion. Before I'd do that, I'd just get the 2011 Fiesta for the same $, and happily get 40 MPG and not think.

Less entertainment value in doing what's been done!

Forrest