Friday, September 19, 2008

Some Details of My Build

Since I am now referring other people interested in building Mopar EV conversions to this site, I thought I would take a moment to provide a few specific details about my build.

Netgain Warp 9 DC electric motor.
Logisysystems 550 amp motor controller.
Trojan T-125, 6 volt deep-cycle batteries - 26 wired in series for 156 volts.
Manzanita Micro PFC 20 on-board battery charger (variable input voltage).
Iota DLS-30 DC-DC Converter to provide 12 volt system & control voltage.
Xantrex Link-10 battery bank monitor.
Digital volt meters for battery management - 26 total, one for each battery.

The car has manual steering, drum brakes, no air conditioning or power anything. I am using the original 3-speed manual transmission but without a flywheel and clutch. The 3-speed is much lighter than a 4-speed manual trans. Most normal driving will likely be in 2nd gear, but I will be able to shift without the clutch if necessary. I'm also retaining the original 8 3/4 rear end with 3.23 gear ratio. I may swap in a much lighter 7 1/4 rear end after the build is complete, although the brakes are much smaller on that rear.

8 comments:

Anonymous said...

I'm wondering what your master vision is for all 26 of those volt meters?

I'm guessing you're planning on putting a block of them in some kind of cluster in the trunk and another cluster under the hood (unless you're planning on making the dashboard look like Kitt from Knight Rider).

An inquiring mind wants to know!

Bruce said...

LOL, as with almost everything on this project, I don't have a set plan for this. Most likely they will be laid out on a board in the trunk, or perhaps where the back seat is now. It's one of those things I won't know for sure until the day I actually install them.

brad said...

Thanks for the response! I like how this project is an adventure and things happen organically as you go (makes for better blog reading as well).

I never considered the backseat area, but can now definitely see a simple lightweight pine ledge or bench (wrapped in auto fabric) with all the meters proudly on display.

Could be a really nice EV touch.

Anonymous said...

Just curious... I was looking at the selection of motors available from Net Gain. I notice that they make all of there motors in a version with a tail shaft that can be mounted in place of the tranny and hook directly to the driveshaft.

My question is: With your concern over weight and battery placement, wouldn't it have been significantly better to use one of these motors? You would have gained extra room in the engine bay for battery clearance, avoiding the cutting of the K-member. You would have saved the grand it cost to machine an adapter plate for keeping the tranny. You would save 100# of weight considering tranny, bell, shifter, adapter plate, etc...
There is an old formula racers use that converts 100# into 10 rear wheel horsepower, and equivalent to .10 second ET over a quarter mile track. Quite a significant amount for a gas burner. Must be at least as significant for a smaller electric motor.

Not being smart... Just genuinely curious if there was a better reason to go your route.

Thanks!
Dave, aka ratio411

Bruce said...

Dave,
Dang man, those are some excellent questions and really made me stop and think.

Remember, I have never done a project like this before so my decisions were all based upon the limited information gained from research before I began. That's one of the reasons for doing this blog - to let others benefit from what I am learning.

That being said, when I was researching my motor choice, I did not know what the trans adapter was going to cost me, but I was thinking I could do something significantly cheaper. There are ways to build them yourself on the cheap, but in the end I decided to make the big expenditure because it turned out to be such an important part. I also paid more to get it done locally and quickly - instead of having to wait two months at this stage of the build.

Originally, I looked at the TransWarp motors and liked the simplicity of eliminating the transmission. However, there really was a cost benefit to going with the Warp 9 and the adapter plate (although less than I originally thought). The TransWarp costs about $600 more. It still would have required some method to reverse the motor, such as a more expensive controller/contactors. It would also have necessitated using a different, custom driveshaft.

In addition, the motor itself, due to its size, would still have to have been mounted in roughly the same location as it is now, so space was not a factor in my decision. I also didn't know until recently that I would run into the K-member problem.

It was also very important to me to keep the 'look' and operation of the Duster as close to stock as possible. I really wanted to keep the shifter. I would like to have kept the clutch but just couldn't justify it.

Lastly, I don't think there is too much of a weight difference between the TransWarp setup and what I eventually used. If I had a 4-speed instead of the 3-speed, that would have been more of a factor. The Mopar 3-speed is actually not very heavy.

Regarding the weight issue, my plan is to do the build the best way possible, then work on eliminating weight in areas that don't affect vehicle operation.

So there are my reasons. And honestly, now having gained the experience, I would still choose to do the installation the same way.

George said...

Great project. I got the link from AutoblogGreen.com. I really like what you are doing and want to view the progress, but I too have questions. I am curious about the choice of 6 volt batteries vs 12 volt specalty batteries from someone like Fullriver or Optima other than cost and weight?

I have an older truck that will need a motor eventually but the body is close to showroom condition and this option sure is appealing. With my solid tonneau over the bed I have plenty of room for batteries and I could include a small portable generator and battery charger for emergencies.

Keep up the good work!

Bruce said...

George,
Thanks for visiting my site. I chose 6 volt batteries for the extra storage capacity. This will directly relate to better range than with 12v batteries. With lead-acid technology, the amount of storage is directly related to the amount of lead you have. Two 6v batteries in series have lots more lead (storage capacity) than one 12 volt battery.

A good place to play around with different combinations of equipment & results is the EV Calculator located here:
http://www.evconvert.com/tools/evcalc/

Your truck sounds like a good candidate for a very cool conversion IF it is not too heavy. From what I have found, it seems like 'usable' conversions are a maximum of 4000# when complete. You might want to find a truck stop and see what your weight is to begin with, then estimate what you would end up with. You could always sacrifice some range and use 12v batteries to save a lot of weight.

Jesse said...

Did you finish this project? Im wanting to do this to a 71 scamp!!