Ok looking some info on the ev6 vs ev12 injector. I'm currently running the ev6 injector with the flat end version of the 225bhp engine but am looking to know should I really be using the ev12 version with the extended tip? Here is the part numbers of the two different versions of the injectors, they both have the same spec apart from the tips.

Audi TT 225hp injectors EV12 06A 906 031 J / 0 280 155 892/893
Audi TT 225hp injectors EV6 368cc 06A 906 031 BC / 0 280 156 063/064