Using Automatic Transmissions

[mechman600]

Powerglides make good transmissions for EVs. And the torque converter can be eliminated in many transmissions. Do some searching in DIYelectriccar.com.
Here's a good thread:
The Reasons why Automatic Gearboxes WILL Work with EV's & how to do it.. - DIY Electric Car Forums

[gone7]

Here is a possible scenario. I want more room; similar to my Town Car. In the decision-making process, the wife and I believe we still want the safety and space of a four-door sedan. That said, it must be at least a mid-sized car, and aerodynamic as much as possible.

A possible candidate is a late-model Lincoln LS with a bum motor. It can be had for a couple thousand, but comes with an automatic. Mechman600's post is helpful in this regard, along with Torque Converter Lockup in the wiki. And obviously, there is no inexpensive way to switch to manual. I have checked two-speed aftermarket trans with electric shifting; rare as hens teeth and I'm afraid to ask the price.

So far, the big issues are hydraulic pumping losses, heat and torque converter lockup mods. Once the clutches engage, it is direct connect, so I can't imagine any mileage loss to be significant at all.

Perhaps a very low-stall converter kit might do the trick, coupled with the lockup mod idea. Maybe an external hydralic pump with a small, presure-controled motor would work well. Just a couple thoughts.

[mechman600]

If it's an electric Town Car you want and a manual gearbox isn't really a viable option, I say go with the automatic.
In your current town car, at what RPM does the torque converter lock up if you have the gear shift in third? As an EV this would likely be the gear you would use on the highway. Does the torque converter ever lock up when shifted into second gear?

If using an automatic kills 20-30% of your potential range, simply adjust the size of your pack accordingly. Besides, with an automatic doing smoky electric powered burnouts would be that much easier!

[gone7]

I was looking at a late model Lincoln LS; a mid-sized car. The automatic problem will probably be fixed with an aftermarket controller to allow a TC lock-up and remove all slippage. Therefore, from other forums about that issue which I've read, it appears that an automatic may actually become very efficient, and lower the cost of an electric conversion to boot.

BTW, I'm not really worried about burnouts. Fast acceleration is more important.

[vskid3]

The '00-02 LS could have a 5 speed manual with the V6, so don't be too quick to settle for an auto.

[mechman600]

I wonder how a giant (read: awesomely cool) warp 11 or warp 13 would suffice direct driving your driveshaft. A quick search reveals that a warp 11 is good for approx 300 ft/lbs @ 1000A. I would think that a warp 13 @ 1500A would be plenty for direct drive. Max continuous RPM is 3000, which equates to 60 mph (800r/mile tires, 3.90:1 ratio). Redline is 5000 - 100 mph. That will do.

192V*1500A=288kW. That will do.

The big advantage to rear wheel drive, direct drive, is a wide open engine bay to fit biblical amounts of battery, allowing full use of the trunk. Since viable wheel motors are not available, I see this as the best option.

[gone7]

I still like the idea of a couple gears forward plus reverse. Electronically operated would be really cool.

However, there are some really good ideas out there about using an aftermarket or custom transmission control module to make an automatic torque converter lock-up when needed (pretty soon after a little speed up) while allowing for decent shifts at optimum motor rpm range. Holding lock-up on coast would allow regen, too.

It is beginning to look very doable, as well as cost effective.

[mechman600]

I honestly don't think regen is going to be an option in your Lincoln. The largest setup available (at a "reasonable" price) is the AC50/Curtis combo, which will not suffice when it comes to moving a whale like a Lincoln around at any speed for any length of time. I highly recommend going with a gigantic DC setup or you will end up disappointed. An AC50 will not provide the spirited acceleration you desire. And the "talk" out the is that regen braking really doesn't gain you more range vs simply spending that money on more lithium.

[FieroChris]

this is one of the cleanest AT installs I have seen...

Electric Vehicle Conversion - AC Project

it idles at 400rpm to keep the pressures up in the transmission.

[FieroChris]

oh... and the ride along test drive video...

http://www.youtube.com/watch?feature...&v=1ZmFNKamTQg