Stock calibration, differences between RRB and RRD

[arielrenostro]

Hi.

I would like to know why exists differences in the injection timming between the stock calibrations Civic-Si-RRD-1-M12 and Civic-Si-RRB-1 for Civic Si 2006-2011 South America.

I have this question because after flashing the Civic-Si-RRB-1 (stock equivalent) with modifications in AFM flow and disabling the O2 second sensor, was necessary ~13.5ms of injection time to reach 0.88 lambda at ~7500RPM and full throttle. It seams higher than normal for me, but it almost matches with the injetor timming of RRD calibration. Today in Brazil, premium gasoline is E25.

Now I don't know if it's a problem in my car (maybe the injectors or the fuel pump) or if the fuel timming should be a little higher for Brazil.

My car is a Civic Si 2008 with the ECU 37820-RRD-M11, Skunk2 Alpha header and K&N V2 SRI Intake, injectors and fuel pump stock. I uploaded a datalog to show better what is happening. Now I'm running only in closed loop, with lambda targets above 0.85, because my injectors are reaching 95% of duty in some cases.

Thank you in advance!

[Spunkster]

You would have to ask why Honda tuned them differently, as we are using what Honda did.

[arielrenostro]

Thanks for the answer, makes sense!

Is there any guess why it's different? For my ECU, which tuning you think should be the correct one?

[Spunkster]

what is your ECU part number?

[arielrenostro]

37820-RRD-M11

[Spunkster]

Then your best bet would be to use the RRD based calibration.

[arielrenostro]

I want to bring you the end of this story. The RRD was the right tuning, and the injector timing was correct. My vehicle had a fuel pump problem, and fuel pressure would decrease as demand increased. I replaced the fuel pump, and now everything works perfectly!