Hello!

I know there is a few different n75 valves that you can use on the 1.8t engine.
And the n75h is the so called "racevalve"

But I have read that the n75h can cause trouble with cars that have DBW throttle.

Can you make the valve work good if you change something in the ECU software?

If I understand correctly the valve makes the engine hold boost a little longer and also the boost pressure is gonna go up maybe 0.2 bar over stock boost pressure.

Is that gonna make the engine go "limp home" if the engine is bone stock?
Or can the ECU compensate the small difference in boost pressure?

Waste of time. You can make 500+ hp with the stock valve or you can make 0hp with your stock valve. Changing it is not going to give you anything.

It's a valve with spring and electromagnet inside. What's there to revise?
You can use one from 1990's from an Audi S2 or you can use one from 2010. It makes absolutely no difference, they all work the same way. What usually fails is that the plastic gets very brittle after 15 years or they start sticking because of dirt inside. But there is no "better working" or "stable" or other bull$hit, because it's just an electric magnet!
How well your boost control works depends ONLY on the calibration, not on what valve you use.

The clueless tend to be superstitious.

Cerips, that was what I thought, thanks for the answer.

Nyet, was that sentence meant for me or just in general?

Why I was curious about the n75 valve, are because I'm from the saab-scene and with the Saab engines you can swap the magnetic valve to an newer one that are cheaper, more stable and faster.
So I thought it was similar for Audis valves.

In my experience these N75 are better to be installed in high boosting engines. In stock boosting or low boosting there
is no gain except the PID overshooting that you will face as overspeed described!

If ECU requests 0.5bar, then you will get 0.5bar what ever you do and you just get a PID overshooting!