No, rl is actual engine load. There is no way for rlmax to "cap" it via feedback loop through the boost PID.

It is entirely separate.

Requested load gets converted to requested boost, which is compared with actual boost to drive the wastegate.

At NO TIME is rl compared with spec load in the boost PID, it is done entirely according to boost.


I was assuming you were talking about the boost taper, not the difference between stock and tuned. Obviously, you need more WGDC for more boost.

If the PID result isn't high enough, likely you are hitting IMX

Many thanks so far nyet!

But why is the actual boost pressure of the tuned file above ca. 4500 rpm nearly the same as the stock file? Especially when the wastegate is trying to increase charger-RPM (-> boost pressure) by closing the WG.

Imho it's still an exhaust system problem or is there anybody who can eliminate this theory?

Increased IMAX! There is no difference in actual boost with more DC of N75 @ RPMs above ~4500.
Would be a shitty calibrated PID if it couldn't manage to hold boost with stock file. I think the Audi guys are capable to do this right.

So there is a mechanical issue.

Either the WG isn't "strong enough" to hold back the exhaust gas pressure (in the manifold) ->(Could be some issue with the spring, diaphragm, N75...

Or... if the WG IS able to hold back the pressure... there must be a too small delta of pressures before and past turbine... -> charger RPMs are too low for desired pressure.
In this case the exhaust gas system is limiting... most likely the cats... Could be that they are blocked in some way...

Attached the files... one reference file... and one with increased I-Limit.