Its just a G4 because if you read closely you can see it says JB4. On the newer ones Terry labels them JB4 which is the G4 or he will lable the G5 in sharpie marker. Now the G5 says G5 and the G5 ISO says G5 ISO in sharpie marker. So you probably have just the regular G4 and depending on when you bought it you have the board with the 18ohm resistors in it. open it up and see if you have the 15ohm resistors because that itself makes a huge difference. Good luck
A/W E92 335i M-sport with JB4 G5 ISO/ E40 WEDGE PERFORMANCE BACKEND FLASH, Alpina TCU flash for AT/Switch-tronic +AR Downpipes, Stett gen 1 intake, Wagner-Tuning FMIC+RB Turbo setup/ RB PCV Valve+ Akro exhaust+60% E85/93 mix,+ HRE P40S wheels, KW coilovers, M3 sways,+BMW performance CF Mirrors, BMW Performance CF deck lid spoiler,+ CF interior trim, p3 vent boost gauge,+ LUX angel eyes (11.73@119mph on street tires) NO METH!