G5 is the new circuit board that is now standard in the JB4. It has more processor speed & memory than the G4 or original board. ISO is a beta system that is being tested that divorces boost control from the stock ECU.
FMIC = Front Mounted Inter Cooler. I have replaced the stock unit for a higher capacity one. I got the JB4 because it best suited what I wanted to do, has the largest user base & IMHO has the best product support.
2013 BMW 135is 6spd conv - 2011 BMW 335is Coupe JB4/ISO
2010 BMW X3 - 2009 Ford Expedition 4X4 EL - 2009 V-Star
2003 Nissan Xterra 4X4 - 1998 Ford Ranger 4X4 Splash
Last edited by bear-avhistory; 12-10-2012 at 07:44 AM.