Hey all, my Accent finally bit the dust, and gave me an excuse to pick up a project. I've been a lurker here for a while, and now intend to join the community.
I just purchased a 1993 Subaru Justy. For those of you unfamiliar with the car, it's a compact four door, 3 cylinder on demand four wheel drive with a CVT. I got it for 1000 bucks Canadian. It has 90k on it, but the odometer rolls at 100k, . The guy claims to be the original owner and doesn't seem like a giant ***, so in the end, who knows....
My end goal is to disconnect the rear axle from the rest of the drive train, and hook up a motor/generator to it with enough battery power for a day of city driving. This will allow me complete battery in the city, regen braking, and optional ICE backup for exhausted batts/highway. Also, I hope to be able to rig up a system to allow use of combined ICE and electric four wheel drive to help move about in Canadian winters.
I want to create a vehicle that is more efficient and much more capable then anything available commercially at a fraction of the cost.
First things first though, I want to gain control of the CVT. I want to be able to control it manually, and I suspect this will be no easy task. There is very little information available online on this transmission. I haven't even been able to discover the max and min gear ratios yet. But if I am able to gain complete manual control over the transmission, I should be able to drastically increase fuel efficiency with constant acceleration close to best fuel/power ratio and all cruising at the absolute tallest gear. A final gear change my be necessary.
If anyone has any info please feel free. Gotta go now, I'll be back later, and with some pics in a couple days.
Wow I didn't know there were CVTs in '93. That might be worth looking into. I too would like a CVT for the same reason, have it mapped to go to BSFC rpms for acceleration up until 40-45MPH or whatever and then tallest gear. It'll take a lot of tweaking to code the code to know when you want which mode (because sometimes I'd like to accelerat at 1/4 throttle, I don't like using WOT as my switch).
I'm afraid I can't help with the tranny control. I'd first look at the number of wires to the tranny and then hook up a voltmeter to each one and read what's going on under various conditions. It might not tell you much but you may be able to at least understand what inputs produce a particular output. After that you'd have to 'play' to see if you get the new output you're hoping for.
Welcome, and dōmo arigatō doctā Robotto. I wasn't aware of that early CVT either, but that's the sort of thing Subaru is known for, selling cars with drive technologies not otherwise being sold (FWD when everything was RWD, 4WD when other manufacturers went FWD, etc).
In the US the CVT was FWD only. The sliding gear manual box was used with the 4WD.
CVT in small cars have been around for quite a while. Check out some of the DAF dutch cars.
I have to raise a concern about electric RWD with more traditional internal combustion FWD: Torque production is quite different between these two. I really don't think that's what you have in mind for slick travel conditions. Adding electric assist to (not replacing) the rear prop shaft will maintain ICE for all four, or electric to all four, or combined (4WD mode), or ICE up front or electric in back (2WD mode). My suggestion is to augment the existing drive system, not to divide in to less than the parts.