boost vs rpm curve

[Mark0]

Could somebody explain how properly set/calculate these settings?
My goal is reach 1.6bar, filling numbers 160 on certain RPM, did the test drive and boost gauge showing only 1.0bar max. It's because boost solenoid reducing or what?
Did the conversation on google: 160kpa to bar, and it's giving 1.6 bar...
So, there is any method properly set it? Or i'm too much brainstorming here? Lol

[jrussell]

If you want 1.6 bar of boost (usual method of measuring in bar) then you want 260kpa. kpa is usually an absolute number, not relative to atmosphere. Must be you have a 1 bar wastegate, and the boost control isn't doing anything because you're over target (since you inadvertently set 0.6bar target) anyway.

[Mark0]

I know it's old topic of mine, also forgot to update it for other users aswell.

To make clear, 1.6bar is desired "top" boost for my engine. Turbo's are ko4 from RS4 B5 model fitted to S4 2001.
ko4 turbo's fully opens only applying 0.7-0.8bar (actuator moves all the way) it can be tested connecting compressor and applying pressure, (just don't apply too much) give pressure until actuator stops moving. So in order to calculate your boost "target": 1.6 + 0.8 = 2.40 in kPa it would be 240.

To make clear, you need to know at which pressure wastegate fully opens and how much boost it can handle and add those numbers.
Previous post isn't bad too, just first you need to know what kind boost it can handle and how much pressure it needs to fully open wastegate.

[jrussell]

The target boost does not care when your wastegate fully opens. You take your desired boost and add atmospheric pressure (usually 100 kpa) to end up with 260kpa in your example. 260kpa of absolute pressure, or 160kpa of boost (aka 1.6 bar).

[Mark0]

The target boost does not care when your wastegate fully opens. You take your desired boost and add atmospheric pressure (usually 100 kpa) to end up with 260kpa in your example. 260kpa of absolute pressure, or 160kpa of boost (aka 1.6 bar).

Well, that's way more clear