Originally Posted by Equilibrium Tuning
I just haven't seen the same results here. Both of those spool about 500-600RPM later than I've seen the 1.5XT's spool here on the 8cm housing. I have seen peak torque at or just before 4000RPM. This being said, I have noticed Blouch turbos to be a bit inconsistent and don't know why. Some spool significantly later than others. This is why I generally prefer the ATP turbos.
Also, the small gains on the top end that are shown on that graph are likely from more aggressive timing. You can see the 10cm graph is not as smooth up there and has a stepped look to it. This is usually indicative of a more aggressive tune that is closer to the knock threshold.
Ive often times wondered if the inconsistencies come from different pressure WG actuators. Some people dont know to specify a higher pressure others dont want to pay for it. Another possibility that Ive wondered is both inlet size and whether or not the turbine housing was ported. But as you look around you can find gt/gtx30r's and blouch turbo's and even ATP turbos that spool differently from car to car.
ATP turbos seem to be nice in concept on stock location, but seem to get crushed power and spool up wise by rotated units from perrin etc.