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Auto trans and cluelessness

8K views 26 replies 7 participants last post by  plymouth 
#1 ·
Okay, I fear this is going to be a book and my typing skills are very poor so I will try to sum this up quickly.

I need an electric car on a truly nuts budget. I have a 1984 dodge Omni right now it has a 2.2 ICE motor with an auto and it’s just too costly to run and my summer car is worse. Most people here would die thinking about the MPG’s of that car, so I found out about electric cars and started stalking around the forum’s EV album and all those sites and that lead me to my current plan. I would like to know if there are any major holes in it before I start buying bits.

I know a fair amount of motors and how they work and how to rip them out but I know very little about auto trannys so a little help will be needed there.

I planned on finding an old forklift motor and using that. I have been looking about for one; no luck yet on one cheap enough for me to justify paying for it, though.
As a motor “controller,” I planned on using only contactors, no controller. They are too much cash and seem overkill for a cheap, low range city/daily beating car and I only see 2 downsides: 1) the contactor might weld itself shut cant this be solved with a back up safety contactor? And 2) it would give a bad ride; I am used to old cars so the ride is not an issue. Also, I believe an old Volkswagen Beetle kit used this method, so it can’t be too bad right.

For battery to battery connections, I planned on using home-done copper plates. I can make them myself and I don’t think it would be too costly or I can use scavenged battery cables out of junkyard cars. Has anyone done that before (this is my fall back plan)? Also, I plan on using used welding cables to connect everything else.

The reason it needs to be cheap is that I am a high school senior and soon to be in collage; I will not have money to eat, let alone buy gas. I’m hoping to spend a few hundred on everything but the batteries.

Goals:
Cost: <$500 without batteries
range: 20 miles
speed: 35-40 foot flat/on tops

So, I guess in that probably very confusing mess of words this is my questions to the people that know far more than me.
1) Is there anything I need to do differently to convert an auto than I would a stick? I tried reading a post and I think I would need to find a way to tell the car to shift?
2) Is there anything super wrong with using contactors as “controllers” for a car I just want to limp about in?
 
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#2 ·
Since you want a dirt cheap budget, and your requirements are quite low and should be doable. I would suggest you get a Forklift motor and the Forklift controller and the cables it uses. Usually they are contactor controllers and since they fit the motor, things might be looking good for you.

I would suggest you look up Project ForkenSwift. It's a Geo Metro on a Beer Budget: http://ecomodder.com/forum/showthread.php/electric-car-conversion-project-forkenswift-33.html

Go raid some junkyards and see if you can get loads of forklift parts. Getting stuff cheap isn't easy and usually you just get lucky. I don't see any real holes in your plan, just $500 might be a bit too low, unless you take your time and possible bargain with junkyards. You could also put Craigslist Want adds for EV parts, forklift controller and motors. I did for a few things and I got lots of hits.
 
#5 ·
It is very easy to change the transaxle to a manual, especially since you have to take the ICE out anyhow. I used trans from Omni in a Daytona, so I am sure they interchange. Probably includes Lancer, k-car and others, so they are plentyful. Linkage and shifters may be another story. Manual Omni used 2 shift rods. Go clutchless and you won't have to dink around with pedals.
 
#6 · (Edited)
i would get a new car before swapping a trans in a dodge i own p-bodys the thought of more trans work makes me jump awake screaming at night.

and i would like to use this omni i have its been a AZ car all it life(well till i got it) and a new trans would cost about $150 and that money could be spent on other parts of the conversion.

so i will not switch the trans to a stick



also i like the "idle" idea i cant see it taking off to much range because it would be a really short trip car.
and if that's all i have to do to get it to work with as a EV is loop the cooler lines that makes everything better.

also would a auto shift with a electric motor the same as a ICE?
 
#7 ·
As someone who just converted Auto trans car to EV, I can tell you that you will be removing the transmission from the car to mate it with the electric motor, so if removing the tranny is an issue, you have to find a way to deal with it. I couldn't understand from your post if the issue is removing it or swapping for a different one.

Also, is the tranny electronically controlled or hydraulic ? Not sure what was the deal in 1984, I wasn't even driving back then :D

Either way, you need to preserve all OEM sensors, etc. so tranny doesn't know that engine was swapped, then it will shift normally.

Read the "Auto Tranny how to..." thread on this forum, you'll get some ideas.

Its going to be rough with contactors, very jerky, although TC might smooth it out somewhat. If you idle at 12V from first battery it would spin too fast, hopefully you will use 6V or 8V golf cart batteries, so first battery would idle the motor. Or perhaps just drop the idle and deal with 1-2 sec delay at the start.
 
#15 ·
As someone who just converted Auto trans car to EV, I can tell you that you will be removing the transmission from the car to mate it with the electric motor, so if removing the tranny is an issue, you have to find a way to deal with it.
Since I just bolted up my motor to the trans in my Fiero without removing the trans I'm wondering why you say this?
 
#9 ·
You don't need to 'idle' the engine. Just program your throttle ramp to account for the time it takes the pump in the trans to build pressure and engauge the clutches. After that you can ramp normally. If not programable then just get used to the delay when starting from a stop. Give it part throttle for a second and after you feel it engauge you'll be good to go. It won't be as hard as you might think.

$.02 :D
 
#16 ·
You don't need to 'idle' the engine. Just program your throttle ramp to account for the time it takes the pump in the trans to build pressure and engauge the clutches.
How is he going to program his throttle ramp with a contactor controller setup? Seems to me the slowest he could idle the motor is whatever speed a 6 volt battery would give him, which depending on the motor would probably be rather fast. Using a 12 volt battery as he is suggesting will be way too fast for an idle.
 
#10 ·
I think i could have a idle only battery in the car and have it only run the motor when my foots off the pedal that would be a easy fix and then that would make it so people other than me could drive the car.... on second thought i need a more complex way of doing this.^^
 
#12 · (Edited)
That's my point i will use a extra battery that is off the main pack so i don't have to use up the main pack not moving. Also i am going to need to have a AUX 12 volt to run the lights and all that stuff so whats a small 6volt next to it going to do? i don't think much other than add so more lead over the drive wheels and its going to need it because the only good place i see the main batteries going is in the rear.
 
#13 ·
It might take 1hp+ to run that pump. At 6v that's 124amps plus losses. What I meant was if you have the room for another battery then you would be better off adding it to the main pack. If you own an automatic car now, put it in neutral and with your foot off the brake put it into drive. Note the time it takes and the tug as it enguages. That's sort of what it'll feel like if you didn't 'idle' the electric motor and just used a light throttle until you felt that tug... then floor it! :D
 
#14 ·
I understand the wait idea and if it was ONLY going to be me driving this pig i would probably go that way because i am lazy and like getting things done ASAP than building a bunch of little things that have a minor roll, but there will be a few people driving this car. also i think i rather just loose what a mile? and a half hour building the idle switch things than having to give an explanation to all the drivers on why they shouldn't stomp it from a red light.
 
#21 ·
I must have missed that part. I didn't know people still do contactor controllers.
I think its the cheapest way to go, but also the most insane way of getting this to work.

Doh, sorry, I was talking about making your own adapter plate :D , for some reason I assumed that plymouth would be making his own adapter plate, since there aren't any for auto tranny and he is on extreme budget.
I planed on trying to build my own first and if that turns out to be a total loss I will only be out 20ish bucks in metal and a few hours of my life, then I will have to pay a shop to take care of it.
 
#23 ·
I have had a lot of experience with removing a 2.2 from Omni, charger, Daytona. Since I welded some extra roll cage tubing for support, I removed the whole eng/trans combe from underneath. I got to where I could change out a eng/trans combo in about a hour and a half in my driveway. It is easier than trying line everything up all bent over under the hood.
That's what i love about these cars and why i have had 4(well 4 2.2's only 2 omnis) there is a ton of people that know everything about these things and so far i have not ran into a old fwd mopar fan that wasn't nice about sharing what he knew.
 
#25 ·
I don't know what sort of voltage you are planning but high amperage contactors aren't exactly cheap.
I really haven't set myself on a voltage yet i want to pick that after i have everything. That's reason why i said at the start of this $500 - the cost of batteries because chargers can easily get passed $1500 and that's scary heck even a used 48 volt golf cart charger is around $300 so voltage from what i can see is limited to what i can charge on bord and what the contactors can take without welding themselves. Another reason i am going with contactors is that contactors ebay alot less then you can buy them for, and i will not be pushing and crazy voltage to minimise the jerks from them.

even a lowly forkenswift style golf cart controler gets into the $300+ range.

So anyone know of a crazy cheapo style DIY charger let me know
or any cheapo tips all are good!
 
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