Greddy eManage Ultimate Tuning

I've been asked to tune a Greddy eManage piggyback ecu. How much different is this from standalone and what are some of the things I should note when tuning a piggyback. I've done my own reading but I'd like some feedback from you guys on this. Thank you.

I have played alittle bit with the GMU once I boosted my IS300

with piggy backs just make sure the factory ecu is happy with no CEL and investigate - clamping and open loop mode.

Compared to a stand alone you are only adding/removing timing from what the factory ecu outputs. The EMU logs will show that for example the factory ecu has 20 deg timing at x rpm and x load followed by another variable of correction factor.

Depending on model of car/engine not all features may work properly

Thanks