silly idea to save petrol

[cameron20020]

okay, so ive got another idea, thats probably not all that original,
to save petrol on my vn...

so yes i noticed my engine can still run with 3 injectors unplugged,
and i was wondering....:whistling

if i set somthing up, a microcontroller perhaps, to disable some injectors
on the side of the engine that doesnt have the ego sensor,
for when i am cruising and need little power,

my theory is, i will be opening the throttle more, for more power, thus creating a more efficient fuel/air mix in the cylinders that are working,
and *theoretically* creating a more efficient conversion from petrol to
motion...

umm anyone got input on this? i know ill lose energy on the cylinders that are just sitting there pumping air, also id be needing to isolate the throttle from the transmission kickdown cable when the injectors are disabled, so i dont get it downshifting when more throttle is applied, but yeh hmm

 

[Leebo]

cut a hole in the floor and Flintstone the car dude

 

[levymetal]

highly doubtful. the engine wouldn't produce enough torque to sustain speed on 3 cylinders. i don't know about the air/fuel ratio, not sure if it would change or not, but there is an optimum ratio anyway which is what your computer keeps it at.

 

[michaelw]

Your exhaust gas would be VERY lean and the engine computer would pump more fuel into the remaining cylinders as it reads the oxygen sensor in the exit manifold. Things could get very confusing for the ECU in the long run.
Also the cat converter would not like it too much, again the exhaust gas would be far too lean.

Mike

 

[walesy]

if you want to save peterol but a more fuel efficient car... simple

 

[VH commodore]

it would run rough as guts too, 3 cylinders on the 1 bank not firing...the vibrations would be epic lol

 

[MasterOfReality]

Don't be a tightass

 

[danja]

DIY Displacement On Demand?

1) It would run like ****, you'd need to at least alternate the dead cylinders to maintain any kind of balance.

2) You'd need a special tune, probably a whole special ECU to make it work without completely spazzing out.

3) OEM versions of this also use variable camshafts to deactivate the valves on certain cylinders, good luck emulating that.

4) Re throttle opening and AFRs, the ECU already tried to maintain an ideal AFR. The injector duty cycles are modulated based on throttle position (and other things).

5) If you put the time and effort it would take to get even remotely close to achieving this, into some kind of paid activity, you'd probably make more money than you'd save like this, without the headaches.

 

[greenfoam]

Just pull all the crap out of the calais you dont need and run it lean. It'll work better. Even Holdens cylinder deactivation only saves like half a litre per 100ks, you can improve them more than that standing on your head

 

[VZCalZone]

it still has to move the same weight the same distance. you can try but you can't beat physics I'm afraid