You have cosworth heads right? They are already CNC ported and it would be a shame to mess with them.

Yep if you’re using option 4(MAP), when the engine is off, the manifold is at atmospheric pressure and the MAP sensor reads about 101 kPa. When the car is idling the manifold is in vacuum and would read around 30 kPa. When you’re making 1.5 bar of boost (150 kPa) the MAP would read about 251 kPa (101 + 150).

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