I had sport 700 turbos , I was just putting my car together with 2871 turbos when we tuned these turbos..... After tuning them I wanted them. I tested the 2871's since they were already on. The problem with the 2871 turbo is that the wheels are miss-matched, The compressor is much larger than the turbine wheel. This caused the backpressure to go through the roof at higher boost levels. Pretty hard on the engine. These turbo have matching wheels are are truly synergistic! I cant wait to get my car back together with these and 2.5" intercooler pipe and two fuel pumps to see what they really can do!!!!