Fuel Economy, Hypermiling, EcoModding News and Forum - EcoModder.com - View Single Post - "ADDING" a rear engine to a FWD car to run at the same time.

ciano22 · 01-24-2015, 03:40 AM

Lol no snow or hills to worry about where I live. lots of rain though... and potholes.

The car has no AWD counterpart,so I guess I'll have to find or build a subframe for it, but it is auto! I figured that there would be issues trying to get the gas motor to turn off completely, but I'm ok with just leaving it on. Like I said, running the gas engine in 4-cyl mode and just using the electric motor to assist would be great. The 4 cyl engine can keep the car going up to 75 mph at less than 2000rpm before the car turns the other 4 cylinders back on. With the engine loaded by the recharge mechanism, it may be a little harder though.

If I could find a way to do simple edits on the afm of the gas engine and out put of the electric motor, I think I could interface them for 3 modes.
1. Gas mode. The electric engine is just completely off and charging.
2. Econ mode. The car is only in 4 cyl mode and the electric motor only engages when the gas engine reaches 1900 rpm. This would be kinda tricky, but if I could limit the gas engine to 2000 rpm, and have only the electric engine respond to any further throttle, that would be amazing. I might have to set up something on the physical gas pedal for that. Basically, the electric engine will just help accelerate the car and leave the gas engine to cruise.
3. Sport mode. Well, more like drag mode. Car is in V8 mode only and the electric engine is on. This one would be set up so that I floor it, the electric engine immediately applies a ton of power, which i Will have to dial in, and then, as the gas engine begins to take over, the electric engine stops.

This is all theory though. Figuring out how to do this is gonna be fun. These are the easy modes too. Gas engine off mode and prius mode would take waaaay more work.

I looked around for some electric motors for sale, and the ones that I found were not very powerful and were very expensive. I found one with 138hp that costs $4k. As of today, you can buy a scrapped model S for $20K. I am optimistic that I will be able to get the tesla back end for less than 10k by the time I want to do this. The battery is the most expensive part of those cars, not the motor.

01-24-2015, 03:40 AM	#4 (permalink)
ciano22 EcoModding Lurker Join Date: Jan 2015 Location: Houston, TX Posts: 13 Thanks: 3 Thanked 1 Time in 1 Post	Lol no snow or hills to worry about where I live. lots of rain though... and potholes. The car has no AWD counterpart,so I guess I'll have to find or build a subframe for it, but it is auto! I figured that there would be issues trying to get the gas motor to turn off completely, but I'm ok with just leaving it on. Like I said, running the gas engine in 4-cyl mode and just using the electric motor to assist would be great. The 4 cyl engine can keep the car going up to 75 mph at less than 2000rpm before the car turns the other 4 cylinders back on. With the engine loaded by the recharge mechanism, it may be a little harder though. If I could find a way to do simple edits on the afm of the gas engine and out put of the electric motor, I think I could interface them for 3 modes. 1. Gas mode. The electric engine is just completely off and charging. 2. Econ mode. The car is only in 4 cyl mode and the electric motor only engages when the gas engine reaches 1900 rpm. This would be kinda tricky, but if I could limit the gas engine to 2000 rpm, and have only the electric engine respond to any further throttle, that would be amazing. I might have to set up something on the physical gas pedal for that. Basically, the electric engine will just help accelerate the car and leave the gas engine to cruise. 3. Sport mode. Well, more like drag mode. Car is in V8 mode only and the electric engine is on. This one would be set up so that I floor it, the electric engine immediately applies a ton of power, which i Will have to dial in, and then, as the gas engine begins to take over, the electric engine stops. This is all theory though. Figuring out how to do this is gonna be fun. These are the easy modes too. Gas engine off mode and prius mode would take waaaay more work. I looked around for some electric motors for sale, and the ones that I found were not very powerful and were very expensive. I found one with 138hp that costs $4k. As of today, you can buy a scrapped model S for $20K. I am optimistic that I will be able to get the tesla back end for less than 10k by the time I want to do this. The battery is the most expensive part of those cars, not the motor. Last edited by ciano22; 01-24-2015 at 03:46 AM..