IIRC, with E85, the Sport 500 is the only turbo smaller than the 2860 that he would recommend. I was surprised since it is such old technology. I guess the 2860 is that good, and the Sport 500 compressor and turbine sizes are balanced well, and work well with that housing. If using the 5 bolt housing, might as well use the 2860 (with breather mods). [my words]