Hi there,

I installed an MBC which i made myself 2 months ago and i'm very happy about this unit. Before installing the unit i did change the oil and filter and spark plugs since there was about time to do that again. 15 psi is about what you should keep as a maximun boost if you haven't done any other changes inside the engine. I see that you run 94 octane, where i live we are able to get the 98 octane which gives a lot of improvement to the car. I believe that the turbo pressure regulates itself due to the amount of exhaust coming from the engine besides what is programmed in the ecu. With an MBC you cannot get 15 psi in the first gear. But you will notice that the pressure inside the manifold will build up faster when tightening the spring inside the MBC. There are 2 ways of installing an MBC. Here are some pages to look at.

http://www.geocities.com/chmwatson/FAQs/mbc.html

http://homepage.ntlworld.com/mj.slater/dbsmotorsportwebsite.htm