Could be due to the E85. Up here we can't get E85 at the pump so all of my judgements are based off pump gas. On pump gas we find the Blouch turbos to loose efficiency after 20psi or so. One of my friends had his V9 spec C 207 max out the efficiency of a 1.5 with an 8cm housing at 375whp at 20 psi to the point it made the exact same hp/tq at 24psi but with higher IATs offsetting the increase in airflow, which probably could have been taken care of with a larger IC but that's for a different discussion. It is larger than the 2867 so it would make sence that it would make more power if you could find a way to keep it efficient in the upper RPMs and higher boost levels. Which is probably what you're seeing with your E85.
On our pump gas the 1.5 usually taps out around 370-390. We've run gen1 2867s into the low 400s on the same gas. But generally they end up around the 360-380 mark unless the motor has a bigger exhaust, higher compression, or bigger cams. I can't say as to what a 1.5 would make with those cause no one around here bothers with Blouch on a build that extensive. But again differing results could be largely due to pump gas vs E85.
I've also personally seen too many catastrophic failures of Blouch turbos and no failures of Garrett's so I don't trust Blouch turbos....so I'm biased in that regard so take my Blouch comparisons with a grain of salt.
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You can still find them at some retailers who had decent inventory.
