Well for starters, I would rip that system out of my car and call it a day. I'm saying that because I was one of the first with that system on a 370z. Mine is currently collecting even more rust in a box ($10k box of shyt
)
Now as far as your problems with no boost. Well that could be several things due to the massive amounts of piping that system uses.
1. When was the last time you changed the oil. The piping around the filter is very tight and you have to remove the piping to get the filter off. I have personally had issues with it not getting put back together properly and blowing the two apart.
2. Check the connections to intercooler on both sides. The connection points are hidden and do like to come apart as well.
3. Check your piping seals under the car. I had mine replaced with proper V-clamps and it solved all my boost leak problems. The clamps they provide are garbage.
4. With this system you really have to check you oil/change it often. Due to the fact it has to travel so far and you are leaving a ton of old oil in the system constantly. If you go to long you will "pop" the timing solenoid and the car will sputter and sound like it's going sound, well just horrible. The car will not run worth a crap (you will be lucky if you get over 25mph). Also shoots out white smoke.
5. Very important as well. Check your filter. With it being exposed, it will get dirty quick. I actually almost imploded mine due to it being dirty.
I hope these suggest help. I have a ton of experience with this system an just about every problem you could possible have with this system. From it burning up cats to boost leaks. Honestly their hose clamps and boots suck.