Well for those who wanted to know how the K5-660R with a dual exit 47mm blitz gate stacks up.... here you go. I am pretty happy with the results and it would be interesting to see how it directly compares to the T04Z with the equivalent 0.81 housing instead of the 0.61 it now has...
Remmeber we use it for drift so we are looking at low and mid range...top end is nearly useless to us so i choose two housings, the #7 (10cm ish) and a #9 (12cm ish)
This graph is running the smallest rear housing the #7... and 16psi, we will try the bigger housing after tassie just to run a back to back comparo on response differrences vs top end gain.. We are happy with the #7 housings response and peak power considering how low the boost is. I reckon with some cam timing adjustment it can be further improved on... atm engine is 100% stock internally apart from a 1.2mm head gasket which was already fitted when i bought the front cut.....
Peak torque @ 4200rpm
peak power @ 7000rpm
all run at 16psi.