Bigger injectors?

[George Evo]

Hello.My name is George,new at this forum and on motecs.

My question is why with the oem ecu running 11.4afr @7000 @ 1.4-1.5boost, the injector duty is at 92% and with the motec the injector duty is over 100%!Nothing changed between ecu change.
My car is an evo8,evo9turbo,hks264 cams.

Could you explain why?Cause I'm ready to buy bigger injectors.

Thanks in advance and I am waiting for your opinions.
George

[Scott@FP]

Depends on how the ECU calculated Inj DC%. Over 100% is simply impossible, you cannot bring an electrical circuit either high or low for more than 100% of the time. Some ECU's do not include some trims or the battery comp (inj latency) in the DC calc, and some may report over 100% because that is the commanded/calculated PW vs time available, not the actual PW vs time.

In your case, if both ECU's calculate Inj DC the same, a trim (including battery comp) is different.

[Gaston]

I would try to increase Fuel Pressure first, just to test what happend with Lambda !

Did you try it?

Cheerrsssss

[George Evo]

No I did not try to increase fuel pressure cause I havenot fuel pressure regulator.
Scott,if I will find the older log and post it,you will see that the duty cycle was actually 114%

My injector scaling is 12.
Could somebody tell me the battery comp,injector current and peak hold ratio for evo 8 stock injectors?
Thank you

[Mazi]

You can find startup file here with all basic calibrations included:

http://www.motec.com.au/downloads/startfiles/

[George Evo]

I saw it but everything is the same as mine!
Seems that I will go to bigger injectors.

[Mazi]

Stock fuel pump is not able to follow the manifold pressure over 1.4bar. I have good experience with Walbro 255 HP fuel pump (not FiA legal). Stay away from clones in black color! Additional 10AWG wire from pump relay to fuel pump will increase fuel flow significantly. Do not remove resistor pack if you are running "plug in" ECU. With standard fuel pressure std injectors and 102 racing fuel you can go over 400HP @ 2bar peak boost and 1.7bar @ 7 kRPM. Additional 1 Bar of fuel pressure will deliver enough fuel up to 470HP. If you want a smooth idle it is necessary to change the fuel pressure regulator. Double Bosch 3.8 bar (Porsche??) in parallel connection is an nice solution.

[George Evo]

Problem solved!
Injector scaling must be 22 instead of 12 as it was when I bought the ecu!
The reason of my mistake is that in the help menu says that turbocharged engines,injector scaling is between 10 and 15 , so I select 12.

Fuel pump I have sytec which is walbro.
Mazi except the additional 1 bar of fuel pressure,I also need and a forged engine to reach 470

Another question.
What injection timing you're using for idle and what for cranking?
Thank you
George

[Mazi]

IJPU has nothing to do with over 100% duty. You are short with fuel.
Keep tank full if you are running on the dyno

Injector timing is around 200 deg and is usually not critical. It is a nice post on the forum from one of motec guys about injector timing setup.

You have a nice setup

[George Evo]

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