How can you tune beyond the stock values of an OEM ecu

Hello everyone, I am fairly new to the car tuning scene and I'm full of questions.

I have a project that I'm acquiring knowledge for, so here is my question.

I have a w204 c220d mercedes and i want to tune the stock ecu with WinOLS what I find in the maps are stock values for example max torque request, max RPM, max air pressure etc.. are already defined in those axis of the maps. If I go for a bigger turbo I will have an increased air pressure and flow also I will have more requested torque, so how can I add those new undefined areas to the map of the ECU?

With my current knowledge I can think of editing the axis to have a higher value. For example instead of having the max rpm value be 4900rpm I will have to edit the axis of the map to 6000rpm while maintaining a 16x16 map same size but different axis values. Does this make sense? Will this create problems?

Thank you for reading my post, I hope that you could help me find some answers.

I don't think you can look at it that way. What you're saying makes sense, but unless the two turbos are exactly related so that the bigger one is a scaled version of the smaller one, you wouldn't be comparing the same curves by doing that. Each compressor has it's own map based on speed and pressure ratio or discharge pressure. You need to rebuild the map based on the turbo/compressor you're adding. If you have a specific turbo in mind, you should be able to get the map from the manufacturer and plot some points using the same X and Y axes as the OEM map. You can see how the two are related, and then adjust your points in the stock ECU based on the turbo you're installing.

I hope that helps.

Hey there Achraf I think Kristan might have missunderstood you, yes you can extend the working end points of your graghs by changine the axis points. What he is saying is you would still have to change all the flow graphs to match what your new turbo would flow. But yes to extend your graghs to 6000rpm or to the expected boost level you can totaly do that. I tune mainly diesels but they work the same way. (I am also not a tuning veteran but have done quite a few) Any time you change a turbo or injectors you have to modify those flow graghs to what they will flow, he is totaly right about that. On a side note I just tuned my Ford 6L diesel with compound turbos to double the factory commanded fuel and boost and up to 4200rpm in my boost/fuel delivery by doing exactly that - extend the axis points - and its very smoke free and fun to drive!! Happy tuning!!