LBZ Tuning / Scanning basics
Hi All,
Well, so everyone is not totally lost with the new Bosch ECM I thought I would give a very basic overview of how to do some basic tuning.
Firstly, this ECM likes to reference everything to torque values, so that is how the fueling is determined.
The first tables to look at are B1115 & B1116, based on RPM and throttle position this table determines the desired torque amount the ECM will use for further calculations.
Next is table B1102, this then converts those torque figures into a fuel quantity amount (in mm3). There is of course a few multiplier tables for those main torque tables too. I am sure to the torque reduction requests from the TCM will play a role in the final torque figure passed on to the next process.
So now the ECM has found the desired torque and desired fuel quantity amount it then goes to the pulse table {B0720} that looks just like the one used on the LB7 & LLY, where it converts the desired mm3 into an injector opening time.
So now, that is the main pulse taken care of.
This ECM features 3 pilot pulses and 2 post injection pulses, however, from the data logging we have done it appears only pilot injection #1 is used.
Boost and Fuel Pressure controls are very close to LLY so there should be no problems for anyone familiar with that part of tuning.
There is 5 base timing tables for the main injection pulse, however, in data logging it appears only table (A) is being used, we need to do more work on that to confirm. I have not been able to determine the purpose of the variable in the ECM that it uses to select each table, but logging it's value seems to always use (A).
Hopefully that might be enough to get some users on the path to tuning nirvana.
Scanning:
You will want to be logging the obvious parameters like RPM, Coolant Temp, Intake temp, Fuel pressure etc, but you should also be logging the DMA PID's to get an idea of the pulse times etc.
These are -
GM.MAIN1Q_DMA "Main Injection Fuel Flow Rate"
GM.PILOT1Q_DMA "Pilot Injection #1 Fuel Flow Rate"
GM.MAIN1CA_DMA "Main Injection Timing from TDC"
GM.PILOT1CA_DMA "Pilot Injection #1 from TDC"
There are other DMA PID's to choose from, but those will be most useful.
As with other data logging, try to keep the PID channel count at or below 24. With the LBZ, 24 channels will give very fast data logging speeds.
Cheers,
Ross
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OK, I'm new here and to EFILive, so I have a few questions. You mentioned that everything references the torque values, so if I adjust the torque values up say 10% in B1115 & B1116, then the fuel, timing etc. will follow??? Or would that be too easy? I've not found anything in any forum or on any website that references any tuning info toward the LBZ. All of the tuning info found is for the LLY and LB7.
