Background There seems to be some interest in this turbo, however there is very little information on it floating around. With that said, I'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 didn'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 I'm lazy and you can feel free to try for yourself if you think you can do better. The S256 map is found at http://www.bullseyepower.com/S200.asp and the GT3582R map is found at http://www.turbobygarrett.com/turbobygarrett/catelog/Turbochargers/GT35/GT3582R_714568_1.htm 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. Next I want to go through the housings to point out some observations. Here's what the two turbine housings look like: Unfortunately, I managed to forget to take a picture of the weird 6 bolt output pattern of the Borg Warner housing. It's basically a hexagon-pattern of 6 bolts situated on the other side the housing (which is also a circle, for anyone who wasn't completely sure). You can use your imagination to figure out how the O2 housing/downpipe would attach. IMO this would be pretty handy, but it's not very common. The Bullseye housing is .55 A/R and stainless steel with a Mitsubishi flange. This particular Borg Warner housing is .85 A/R, steel, and has a divided T3 housing. The prospect of a divided T3 setup is interesting, except that no one really makes a divided T3 exhaust manifold (nor do I forsee people starting to make them). The Bullseye housing seemed to have some casting defects, mostly rough patches within the turbine wall, including this bugger situated at the very end of the exhaust path within the housing: Luckily, the pit has no chance of hitting a turbine blade as it's situated behind the smooth wall to its right. This housing does seem rather small, especially given that the turbine wheel is almost the size of a P-trim. It would be nice to have a little better QC in terms of the casting, as well as the option for a bigger housing (.63, or a .82). The Borg Warner housing is huge in comparison--about the size of the compressor housing (which is roughly the same size as a T04S cover). It also seems to be much better made, with smoother lines/transitions (as expected of manufacturer of their size). Many people have seen the compressor cover from various websites selling the turbo, and it shows the "map enhancement groove" as a sort of inner/outer set of intake areas. I for one never understood what was going on, especially because everyone shoots the same picture from directly overhead. Here's a shot where you can actually see what happens: The outer circle leads to a thin passageway through the inner circle which feeds a second set of inducer blades (SO THAT'S WHAT THEY MEANT!!). You can see one of the inner blades at the very top of the picture, and there is one underneath every exterior turbine blade. Install Notes It should be a pretty straightforward install for most people (not for me because I have the worst luck ever). A few key notes that people need to know: I ordered a flange from Bullseye to take care of the oil feed. It takes care of the fact that the Borg Warner turbos use a BPT (British Pipe Thread), as well as any possible sealing issues. The flange also has a built in .080" restrictor, which will take care of any oil pressure issues. The cover SOMEHOW manages to clear the front water pipe without needing to dent it. This may also be due to the fact that I'm running an aftermarket cast manifold which has a slightly thicker flange to move the turbo closer towards the radiator (I think). Basically, your mileage may vary, but if you do have to dent it, then it's just like any other install. Contrary to what I was told, not everything from a Garrett oil drain kit will fit. I'm using a flange/push-lock setup, and while the flange fits perfectly, the bolts do not. The bolts originally on the Bullseye T04B 50 trim were M10x1.5 25, while the bolts that go in the S256 were M8x1.25 25. Just be aware that you will need two new bolts! It is recommended to run an inline oil filter. David from Bullseye verified that the FP 10 micron .100" filter (the red one) would work perfectly. Just like any other install, take your time and triple check everything! Another reminder--USE PROPER SUPPORT. I know some people don't ever use jackstands and just assume that their jack will do the job, even though they've heard that the jacks will sometimes lose pressure and drop. Well guess what, this actually happened to me. I didn't even notice it, and you know why? I had the jackstands positioned correctly to do their job--save my dad or myself from having a car dropped on top of us.