2011 135i DCT - JB4 questions

[rlddlr53]

Just purchased a 2011 135i DCT

I found a JB4 for the n55 for $300, type A connector for my car.

Is this still worth it if it is a G4 unit vs G5?

I do not plan on doing any other mods other than maybe a chargepipe. Not sure if DV's need to be upgraded.

Is there no difference for me with a G4 unit or should I throw the extra cash to get a new G5 unit ?

Any help is appreciated.