hmm thats a large spike...due to either A. crappy ass bleeder valve mbc, incorrectly set ebc, or the usual crappy wastegate actuator...also excessive vac tube length will play a role in delayed wg opening, which will in turn cause the spike.
I would change the wastegate. I found a website not too long ago that sold a direct replacement for out stock wastegate. It was about $60. I was going to purchase one but I decided to go with a bigger turbo and an external wastegate.
For Sale Got tons of extra parts for mazda protege protege5 engine 2trans