This makes the exhaust path as short as possible, eliminating pumping losses and maintaining full boost pressure. (automobilemag.com)
Large units can draw up to 10 % of the engine's total power when at full boost, although of course, they provide a power increase much greater than this. (en.wikipedia.org)
Coupled with the way Bandai Namco have been flooding the console version of Full Boost with Maxi Boost unit DLC, the rumor does lend credence to the possibility that they don't have plans of bringing Maxi Boost to the PS3 or PS4. (mechadamashii.com)