Improving spool time

[Christod]

Hi everyone,
I installed an MBC+A on an otherwise stock car. It frees things up nicely, although the overall effect that I'm going for is not quite there. I briefly disconnected the waste-gate entirely to see how much performance I was getting and I wasnt really satisfied. 15psi peak boost is fine for me, what I would like is to have that boost pressure show up sooner and at lower rpms, making the car torquey and fun to drive in the city were I never really hit high RPMs.
From what I can tell a full exhaust (downpipe, race cat, and the rest), and on the intake side (open air intake, although this seems not to make any difference until much higher hp numbers based on what Ive read here, intercooler, and delivery pipe) will be the things which decrease spool time.
Ok, so to get the most bang for my buck where should I start? Is there an ARB of spool time if that makes any sense?

Thanks alot!
Chris