First, I would like to say that I have no association with any of these companies (Borg Warner, Bullseye Power, FP, Waffle House, etc.), and that I am doing this solely to provide information to the community. To do that, I will have a post describing the background of why I chose this turbo and a brief section with installation notes, a post describing performance (including logs with wideband and MAP sensor data), and a post with followup on integrity of the turbo. Background There seems to be some interest in this turbo, however there is very little information on it floating around. With that said, Iâ€™ll be attempting to document my experiences with the Borg Warner S200 (Bullseye S256). The compressor wheel for the S200 series comes as a 55mm/80mm 50 trim and a 58mm/80mm 44 trim. The turbine wheel is available as a 61.5mm/69.5mm 16 trim and a 64mm/74mm 20 trim. My turbo is made up of the 55/80mm compressor wheel and the 64mm/74mm turbine wheel. The housing used will be a Mitsubishi-flanged .55 A/R Bullseye stainless steel housing. In trying to pick out my turbo, I was looking at everything from a standard PTE SCM5031E to a divided housing full T4 3582R. This turbo first caught my eye because someone was offering a deal on a brand new one which they didnâ€™t want, so, my deciding factor was actually price. Putting that aside, I also looked at the performance characteristics of the 3582R and the S256. In sheer terms of wheel size, the 3582R would apparently win given that it has a 61.4mm/82mm 56 trim compressor wheel and a 68mm turbine exducer. Pulling up and proceeding to overlay their maps as best as I could brought up some interesting characteristics, however. I realize that this may be hard to read, but Iâ€™m lazy and you can feel free to try for yourself if you think you can do better. The S256 map is found at Bullseye Power Turbos and the GT3582R map is found at TurboByGarrett.com - Catalog An analysis of this overlay shows that they both actually have very similar airflow characteristics, but there are a few very key differences. The choke flow of the 3582R (62? lbs/min) is greater than the S256 (58? 59? lbs/min). The S256 achieves choke flow at a higher PR than the 3582R (roughly 35 psi versus around 22-28 psi) based on the maps alone. The surge line of the S256 is significantly further to the left and does not shift to the right like the 3582R. So, here is a complementary picture of parts-- Ignore the assorted crap on my desk.