Boost/Load Setup in Bosch ME7

Hi guys,

I've been trying to understand how to achieve higher boost than stock 0.6bar on my 1.8T engine on the OEM ECU. The graphs are not set up in psi, mbar or kPa. However, they're set in Load, and Boost in mbar = (Load * 10) +300mbar - 1000mbar. Example: 160% Load = 0.9 Bar turbo boost.

The problem I'm having is trying to understand these three Load vs Torque Request Maps.

1. LDRXN = This sets the maximum boost allowed Load/Boost accross the RPM Range.

1. KFMIOP = Map for optimum engine Torque.

3. KFMIRL = Engine Load Desired.

KFMIOP and KFMIRL are inverses of each other (though KFMIOP only supports up to 94% Load) We can achieve 1 bar boost by only editting LDRXN to 165% Load, however, if we go any further, the other two maps don't have enough rows to support the Load in LDRXN, say if we want 200 Load, and in the other two graphs, at 95% Torque request we have 160% Load max. If we alter one of these to support 200 Load though, we need to alter the inverse too.

I am trying to achieve a 1.3 Bar on a small turbo capable of 230hp without having torque intervention issues, then move on to fueling.

See for yourselves. What would YOU do?

You may have seen this file already, but there is a detailed reference material on the Motronic system. I've attached it. It's light on "how to" details.

To answer your question, try working in relative percentages of the maps, and use inverse arithmetic operations. For example, Multiply LDRXN and KFMIRL by 1.05 (in the area you want to change), and divide KFMIOP by 1.05 for say the last two rows.

On page 45 of the document you have a bunch of parameters you can log while you are tuning. Make sure you record all the different error flags, so that if you get into torque reduction you know why. Then work backwards and try to understand what map can trigger the flag you are seeing.

Thank you Arghx7! That was a really straight forward tip

You're welcome. Please keep us updated on your progress.