SOI or Rail Pressure

by **crd4me** » Sun Jan 24, 2016 7:18 pm

Hi,
I'd like to alter back EOI (end of injection) on a common rail engine that has piezo injector.
Is it ok to tune by advancing MI SOI or do I have to go with Rail Pressure map ? I know this has Pil injection too. I know it works with Rail P up-> referencing to a shorter duration on duration map, but would like to hear what about MI SOI.
Best regards.

by **Remapmaster** » Sun Jan 24, 2016 7:47 pm

It depends on why and where you want to change SOI/RP.

by **crd4me** » Sun Jan 24, 2016 8:01 pm

Thanks Remapmaster for the wize words.
In deed, It is to gain effeciency at part throttle.
MI SOI is very retarded (in the negative numbers at part throttle) because there is a Pil inj event and because of the reasons we all know.
So is altering timing of MI SOI possible or railP the only option to acheive similar effect. Again I'm looking at bringing back EOI (eithet by railP/duration or SOI) which one to chose ?

by **crd4me** » Mon Jan 25, 2016 6:05 am

Anybody else please ?

by **Remapmaster** » Mon Jan 25, 2016 10:10 am

For fuel economy you can advance SOI by ~2deg and increase RP for ~20bars in crusing area. Your SOI is retarded much mainly because of EGR,DPF and other ecology shit. With higher fuel pressure you can spray more fuel at almost the same time.

by **crd4me** » Mon Jan 25, 2016 3:56 pm

I understand what you say, but isn't the Pil inj event explains why MI is so retarded ? I have in some area -7 deg of advance. I can not just bring that up to 0 no ? Remember this is not PD, it's common rail with piezo. On oscilloscope I see 2 pil inj event and 1 MI event.

by **crd4me** » Mon Jan 25, 2016 9:51 pm

Should I be concerned about Pil inj when tuning MI SOI ?

by **Remapmaster** » Sat Jan 30, 2016 5:28 pm

crd4me wrote:Should I be concerned about Pil inj when tuning MI SOI ?

No, no need to touch Pilot injection maps to get fuel economy or whatever. On full load there are no pilot injection anyway.

by **crd4me** » Sun Jan 31, 2016 7:29 am

Thanks for this.
I agree there is no Pil inj at WOT. But in part throttle dont you think that there is some caution to take with MI SOI, because Pil Inj exists? ... sometimes there is even 2 Pil in on piezo-cr system.

Maybe the pil inj are so negligeable (between 1mm^3 to 4mm^3) that it's ok to ignore their impact? or maybe it's because ECU will re-correct timing based on condition of operation as per the EDC16 Fonctionrhamen?
best regards