Nice to see that motor is getting figured out. I'm running it's bigger brother- the 1500cc rxp motor. The 2871 seems like a small turbo for that motor. I was running the 3071 and it was struggling at altitude- got the GT35R now and seems to do the trick! A/F numbers around 11.5 at full boost.
What are you using for an ECU on these motors?
So What is that motor in?? Where does it come from? Watercraft?