Video: how to Pulse & Glide in a Prius - 85 mpg!

[fatman57]

Originally Posted by daring4

Wow, I never thought of turning off the injectors and flooring it! I have just been mostly just pushing it into nuetral to coast in traffic and using the kill switch when I know I'm gonna sit at a light when I stop.

i'm tempted to try it myself...............

you don't know how the ecu will react though so it will have to be trial and error.......the vacuum will also need to be restored before turning them on unless you turn them on with full throttle open..........could be interesting! lol

i just wouldn't want any kickback when i turn them back on.

[Daox]

If I were to try that out I'd want to do a comparison between P&G with neutral and P&G with injector kill. You're still compressing the intake air, so you still have some fairly decent losses there I would think.

[daring4]

Yeah your right Daox, still compressing air in the motor. I've been letting it idle while coasting mostly becuase I dont feel like replacing the starter when I wear it out. I could bump start but that slows the car down even more and clutch replacement is even harder on this car.

Btw, after I saw your grill block I went out and looked at mine and decided to make clear covers for the turn signal pockets. Not gonna block the grill opening in Az!

[fatman57]

Originally Posted by Daox

If I were to try that out I'd want to do a comparison between P&G with neutral and P&G with injector kill. You're still compressing the intake air, so you still have some fairly decent losses there I would think.

i agree.

there will be energy loss encountered from the compression but it could be suprisingly smooth. The engine will also be acting as a flywheel so you regain the energy you would loose if you went from 3000 revs to idle when you change gear to neutral. a small gain but still something.

lots of torque due to a full cyliner - could be similar to a diesel. Variable valve could be made to advance/retard the timingbut that would be a more complex setup.

either way I think something like it will be easier and safer than killing the engine - brakes will still work too.

[5speed5]

You'd get most of the energy back when the compressed air decompresses during the
"power" cycle ("power" is in quotes because with the injectors off, there's no added power...just a decompression). True, there is a bit of loss due to heat loss during compression (imperfect adiabaticity), but that's probably less than friction loss and pumping loss (moving air through the engine as it rotates).

[fatman57]

Originally Posted by 5speed5

You'd get most of the energy back when the compressed air decompresses during the
"power" cycle ("power" is in quotes because with the injectors off, there's no added power...just a decompression). True, there is a bit of loss due to heat loss during compression (imperfect adiabaticity), but that's probably less than friction loss and pumping loss (moving air through the engine as it rotates).

i agree.

and should be easy to plumb into an injected engine - unplug the injector rail and plug a switch in between.

[daring4]

Originally Posted by fatman57

i agree.

and should be easy to plumb into an injected engine - unplug the injector rail and plug a switch in between.

Its easier than that, just pull the fuse/s in your fuse block labeled injector and wire in a switch with inline fuse/s. Mine had two fuses for injectors.

[fatman57]

sounds like a good plug and play option to me..................

takes away what really puts me off pulse and glide in a normal car and thats having to turn the thing off!!!! You can also guarantee no fuel goes into that there engine when you don't want it too