I strongly suggest that you plug the pressure hose right into the wastegate without any MBC or electronic BC in the system. That way you can test the wastegate and actuator. As soon as you start getting boost above about 6-9 psi the wastegate should close and stop any additional boost. If you are still getting 14 psi then you know that the problem lies with the actuator and wastegate.

Personally I don't think the actuator can close the wastegate with 18psi in the system. If your wastegate or actuator is not functioning properly then I suggest you get them fixed ASAP. A nonfunctioning wastegate will toast your new engine too. Perhaps replace the actuator with a stronger one from a newer V70 model.

The Dawes MBC can be used in place of your electronic ECU controls. Whatever boost you run then should be whatever you set the controller for. Race version or regular versions should do the same thing. If the other things are OK, pull the Dawes device and run the car in stock configuration. Process of elimination is how most problems are solved.

The SCARRIEST thing to me is that you are doing these things and not knowing what they do. If you have to ask such questions about this system I suggest that you buy a couple books and read up on the systems. "Maximum Boost" is a great book to learn from. Also T5UK.com has a great FAQ you might want to read. TME http://www.tme.se/ also has a great questions section.

Final Questions?
Did you put stronger rods in?
What are the max HP estimates for the rebuild?
Any Dyno runs? 1/4 mile runs? G-tech runs?
--
Nathan Valles, Black 855R, Tint