i honestly dont know if it gave me any gains, but one thing i do know is that it pulls alot harder. sound is amazing. spool is crazy and bov breaths alot easier.
install was a PITA cause i had no instructions. haha. once u remove the battery and the plastic holder for the battery, it gets alil easier.
also the oem clamps... i swear, sometimes they're position in a way where u know mazda didnt want u to be able to get to them.
reinstall is always alil easier cause u now know how everything goes, and position the clamps to ur liking. hope this was helpful.