Geo Tracker 4x4 info wanted for possible Hybrid use

[bennelson]

Hi guys,

I'm looking for some more detailed information specific to 4X4 Geo Trackers or Suzuki Sidekicks.

Specifically, I would like to figure out if it might make a good platform for a DIY Plug-In Hybrid Vehicle.

I have nearly no 4x4 knowledge or experience, so that's why I am asking. My idea is that a smaller/lighter 4-wheel-drive vehicle might make a good hybrid. The concept is to leave the existing engine (or possibly a diesel conversion) connected to two drive wheels, and attach an electric motor to to the other two drive wheels.

The vehicle would be a "parallel hybrid" - it could be driven with either the engine OR the motor. The downside is that you sort of need TWO of everything; both a gas tank AND a battery pack, etc.

I wikipedia'ed how 4x4 systems work and the Geo Tracker, but really couldn't find any good details of the Geo Tracker 4X4 system. If somebody who has a 4x4 Tracker, and would be kind enough to explain/describe how it works on that vehicle, I would appreciate it!

My understanding is that power from the engine goes through the the transmission, to the transfer case, and normally (2-wheel drive mode) does to just the rear two wheels through a differential. When you are in four-wheel drive mode, power gets split in the transfer case to both the front and back wheels. (Please correct me if this isn't right!!!!)(Also, how combined or separate are the transmission and transfer case on this vehicle?)

I'd like to know if it would be possible to disconnect the transfer case to either the front or the back axle and mount an electric drive motor to that differential. (The motor would NOT connect to the transfer case, just directly to one of the drive axles.)

I'd then want to be able to drive the vehicle from either set of wheels. (Also, possibly driving the vehicle with the engine while doing light regen with the motor.)

I'd like to know if this is possible. I built an electric car and know all the little details that need to be worked out to make that happen. Mostly, I'm looking to find out the details of the Geo Tracker 4x4 system.

I'd like to know if it would be better to put the electric on the front or the back and why. I'd also like to know the vehicle weight and gross vehicle weight and the exact size of the cargo area, as all that figures in to how many batteries and where they can be carried.

Thank you in advance for your help on this!

-Ben

[deathtrain]

yes that how a 4x4 system works. but the gearing in the front axel is a lot lower. what you are trying to do is what one of the new jags does. it has a front wheel drive v6 and a motor and battery pack on the rear wheels. at lower speeds it runs on the EV rear and then once past a set speed the v6 comes on and takes over.

[bennelson]

Yep, something sort of like that.
I think it might be best to keep the engine connected to the rear wheels and just do the electric on the front, but I don't know that for sure yet.

Anyone have any info on the gearing on the front axle?
If it would allow for electric for in town speeds that would be fine. If I knew the gearing, that might also allow me to calculate what voltage would be needed for the electric motor, and thus how much space and weight they would take up.

[deathtrain]

I was thinking about something like this but with the rabbit diesel truck. then put in an axel from a donor car and then attach the motor to that. then have the battery pack in the bed under the bed cover.

[rickjames8]

I thought about doing this as well, so I'm interested to hear how the thread goes.

One thing I could never quite picture was how the gas pedal would work?? Two cables which would somehow be switched?

Recently I found a website where a guy installed a turbo engine in the REAR of his Honda CRX. He just dropped the entire front end of a Honda Accord in the rear, so the car became RWD. Hooking up the shifting and everything worked out surprisingly easy. It gave me the idea that instead of limiting a project like this to just 4x4s (not generally very aero cars) to do some major mods and drop a front end in to the rear of a FWD car like this guy did but hook an electric motor up to one of the axles. The CRX guy did the whole thing on a tight budget and it turned out amazing.

[Ryland]

Andrew Baker's 1989 Suzuki Vitara

There is a photo of the transfer case and transmission bolted together, not ideal for this idea, it does however look like both a two and a 4 wheel driver version were made.
A guy in our local electric auto association is building a hybrid like this only he is using a Ford Ranger, that vehicle had it's transfer case pulled out and there is enough room where it sat that he put an 8" (I think) motor in it's place, he then put a drive shaft from a 2 wheel drive truck in to connect the engine to the rear axle, of course it snowed before he finished so it's not been tested yet but at least with a Ford Ranger that type of setup would work well.
The other part of the Ford Ranger that I liked is that you can fit I think 10 or more T-105 golf cart batteries behind the seat of the extended cab with enough space to check water and still be below the rear window.

[Rick323]

Ring and pinion are the same ratio front and rear.

These are the ratios I found: manual 5.12:1, 8v auto 4.62:1, 16v auto 4.3:1

Transfer case is bolted directly to transmission.

[kach22i]

The guy who built this hybrid 1966 Mustang might be able to help, he has posted in this forum recently. I could not find good details on his drive layout, but there is good "source" material information on his site. See "Home" link below.

Home

I drove/owned a 1990 Geo Tracker for 19-1/2 years before salt killed the electrical system.

1. Smell for gas, could be the fill spout or fittings/vents on top of the gas tank. If you smell gas just walk away, it is a pain in the arse to deal with and can get expensive.

2. The LSI has electronically switchable hubs, I had the manually locking front hubs. A fantastic 4WD system (move aside Jeeps), but with the short wheelbase the car/truck is downright dangerous in 2WD in a heavy rain or light snow.

3. It is fun to drive, not because it is fast, but because of all the driver feedback and peppy feel off the line.

4. Be wary of the exhaust system, I had to mess with mine every couple of years. At one time I invested over $1,000 for an all new factory Toyota/Suzuki system and still had issues just a few years later.

5. I loved my Geo Tracker, Zebra stripes are optional, got complements on it until the day it died.

Zebra Tracker pictures by kach22i - Photobucket

[bennelson]

Originally Posted by rickjames8

One thing I could never quite picture was how the gas pedal would work?? Two cables which would somehow be switched?

Recently I found a website where a guy installed a turbo engine in the REAR of his Honda CRX.

Any chance you have a link for that CRX project?

I've also thought about some sort of project to take a front wheel drive vehicle and add a drive system to the back end, but that sounds like a pretty major thing to do to a car. I don't have much major fabrication skills that something like that would take.

Part of what I would like to do is something that could be repeatable. I'd like to be able to show it off and have somebody else be able to think "yeah, I could do that!"

As for a throttle to control two different drive systems simultaneously.... That's one of the fun details to figure out, but I already have some ideas.

A) Thumb throttle for the electric. Drive the engine with your foot, but have a n electronic thumb-style scooter throttle right on the steering wheel. This would allow the driver to use as much throttle as wanted on either system.

B) Drive by wire cars and EVs sometimes overlap. My friend Tom built an AC Dodge Neon. The mechanical cable goes to the physical throttle body, where it is connected to a , wait for it...... 0-5Kohm potentiometer! He took out the engine, but left the throttle and connected that as the pot for his motor controller!

C) OBD2 connector. On a '96 or newer car one of the parameters of the data from the OBD2 connector is THROTTLE DATA. Connect the OBD2 to some sort of microcontroller (Arduino or something) to grab the throttle data and convert it into whatever type of signal the motor controller needs. Then you still have a mechanical gas pedal to the engine AND have an electronic one to the motor controller. You could also put programming in there that would limit its output to only certain situations, so you could design it to only run the motor on hard acceleration, or under certain speeds, etc.
That's basically the idea behind the EMIS system.
EMIS - Engine Motor Interface System

In other weird thoughts....
If an electric motor was connected to something other than a transmission, an electric reverse would be needed (as you couldn't use reverse gear) but on a hybrid, it might not be. You could always use the engine to back up. I'm just trying to think of what extra parts in an EV system you could skip, because space will be at a premium with both ICE and EV components.

[Ryland]

I really like the single throttle idea, that way you still use the foot throttle if the gasoline engine is turned off, if you have it look at engine load as well (vacuum) then it seems like it could be made to work together in a nice flawless manner.
With the Suzuki I worry about space and weight too because you would only be adding weight, of course with the electric motor you could get away with a 1 liter gasoline engine, where those vehicles came stock with a 1.3L or some even larger engine in them, but an engine like a Metro XFI engine in there might do ok with the electric to help it get up to speed.