I've recently install a Stagea C34 RB25DET and a Wolf 3D v4+ into my R32 GTS4. It seemed to have a bit more mumbo than the old RB20DET, but I didn't realise until I had it mapped on the dyno today.
Early on, it was detonating it's brains, and no subtraction of timing seemed to cure it. It looked like I would be stuck with a paltry gain of only around 15 awkw (I was only getting about 130 awkw, compared with its last outing of 115 awkw with the RB20). Then we threw fuel at it, and everything started to work.
The result:
178.4 AWKW
runing 10psi, on 95 octane Caltex Vortex shyte (I'll bite the bullet and run Ultimate or Synergy in future). May not be a lot to some of you, but I'm rapt.