PowerFC = Different Injector Noise

[Cubes]

Hi ppls,

I recently fitted an AP PowerFC to my R32 RB30DET.

Prior to the powerfc the stock ecu had the injectors making the typical click/clack type sound that could be slightly heard stading next to the car.

Since fitting the PowerFC the injectors have gone almost quiet and can only be heard with the bonnet open and ear next to where the injectors reside.

Would any one know why this is so? Curious thats all.

PowerFC also has a much nicer/stable idle with no occasional pop.

[R31 POWER]

I can't remember what the 20 injectors sounded like but the GTR ones are a little noisey

[Chris32]

Joel, I noticed this too

I believe its to do with the actual load points in the ECU, the PFC having 400, the stock ECU has around 256 or something

At light load, the stock ecu would be set to a more general injector opening setting, to deal with a variety of idle/load types, rather than the PFC having a much more finer resolution and opening the injectors for a shorter time???

Sorry if it makes no sense!

Hows everyones cars going? Mine is back into swing, finished a months holidays so haven't been on here much. Mine currently running 185rwkw due to a shithouse fuel pump, so a 044 is about to go in.

Chris

[Cubes]

Well there won't be any tuning done on the std injectors

I wanted to see how far the stock setup would go with a RB30DET. Definitely a no go.

Just before 4000rpm in first and second the injectors are seeing 100% duty cycle and the airflow meter hits 4.98v.

[natho]

not sure if the rb20det stock ecu uses sequential injection or not but i presume the pfc would?

if thats the case, since only one injector is being fired at once instead of all 6 (or even groups of 3 if its like the RB30ET) then it may sound quieter.

i heard an rb25det running once and you can pick the difference from the sound of the injectors straight away.

[OVL-747]

more than likely it is sequential injection.

[Chris32]

good point, never thought of that