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Old 03-22-2015, 12:39 PM   #14 (permalink)
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Originally Posted by ciano22 View Post
In the future, I want to add a 400HP Tesla motor(or some other powerful electric motor) to the back and set the car up to run like a true hybrid for amazing efficiency, but also be able to run both engines at once for insane power.
Originally Posted by ciano22 View Post
Sorry. I probably didn't explain clearly. The car already has a system which allows for 4 of the cylinders to be shut down, making it go from a V8 to a V4(or inline 4?). My goal for econ mode is to have the car stay in 4 cyl mode constantly, and then use the electric motor to help the small 4 cylinder engine accelerate the car without straining too much.

Simple adding an electric motor to a conventional ICE system doesn't make it more efficient. Cars like the Prius gain efficiency by allowing the ICE to be more efficient by:

-Running Atkinson Cycle, which has greater efficiency but considerably less torque at a given displacement, especially at lower RPM
-Allowing the gas engine to be downsized below what would otherwise be acceptable in an ICE-only car
-Allowing the engine to shut off when not needed, and start back up unobtrusively

Rather than helping your fuel economy, adding such a hybrid system will probably hurt it. Converting mechanical energy to electrical and then back to mechanical is lossy. Running an ICE at lower loads is less efficient, so taking load off of an ICE is counter-intuitive if you're looking to save fuel. Hybrid assist allows a smaller displacement ICE to cruise at higher load, saving fuel. Plus, you're adding weight to the vehicle, which costs energy to accelerate. The only area that might save you some fuel is that you can drive around using grid electricity until the battery is depleted.

Adding an electric motor will definitely give you more power, but unless you do some serious changes to the ICE, you're not going to see economy gains.
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