Boost problems on a 97' 945

[Beadybc]

Hello I'm having problems with:
1) Overboost
2) Not enough boost

I've put a 19t on my 97' B230FK and to help control the boost I've fitted this EBC: EBC Instructions. The solenoid valve is fitted as shown in the instructions but the boost sensor is currently T'd between the recirculation valve and the inlet manifold as I wasn't sure what this in the diagram was:
Screenshot 2023-03-06 164058.png

Any guesses?

- Target boost is 1.2 Bar.
- Current external wastegate actuator spring is rated at 1.2 Bar. (I have tried 0.6 Bar as well)

El problems:

First of all, I cannot tell the system my target boost, it's just not a feature. If I set the base wastegate spring pressure on the controller to 1.2 Bar and the boost cut off at 1.4 Bar then as soon as the car gets near to 1.0 Bar, it will shoot up past 1.2 and the boost will be cut by the controller. The same happens if I have a 0.6 Bar spring in and I set the base spring pressure to 0.6 Bar.

However if I have a 1.2 Bar spring in the wastegate actuator and I tell the boost controller that the base spring pressure is actually 0.8 Bar, the car won't overboost, it will underboost by only going up to 1.0 Bar.

If I use 80%+ throttle, the car will get up to 1.0 Bar of boost and stay there though the revs. If I use 50%-80% throttle It will go back to trying to overboost. The same happens if I have a 0.6 Bar spring fitted and I set the base spring pressure to 0.4 Bar.

So currently it's either drive slow or really fast. Any ideas?