Like myself and Twisted have PROVEN Yetims.
the 2 stroke needs a compressor large unuf to flow BELOW boost.
2 strokes need and MOVE double the air as a 4 stroke for a loose comparison.Much more than a prehistoric 4 stroke, the gulp factor is something that we are addressing for all to benefit from, this gulp factor is what drives the need for a larger compressor wheel..even for moderate airflow.
The tighter hot side bleeds less around the wheel and spins it quicker. Physics
2 strokes tend to be leaky ,,, they need lots of air on the intake side Before they can build boost...
2871 has 2 psi at 3800 ish rpm
2876 has 2 -3 psi at 2700 ish rpm
my testing is on the 800 Doo twins
Twisted testing is on the 800 cats.
Both of us found boost to come up 1000 rpms quicker with the larger 76 compressor..
the twisted kits now come with 2876's m8
Another smart student of mine and OVS is on the newer course of the tighter hot side a/r and again finding HUGE gains in response and transitional power as well as peak gains too..
Unlike a 4 stroke we NEED exhaust backpressure to build before we can build Intake pressure.
typically 3 psi in the pipe to see the first 1 psi on the intake side..
after 22 yrs of this I still learn every season ..
FWIW.. on the dyno I still see power climbing at 10 psi over boost ( exhaust backpressure )..
2 psi over in the pipe is 23% down on power vs 5 psi over boost backpressure.
to date BSP is at 209 hp per 400cc of displacement,, safely..