The turbo on the MPS will be a similiar size to a Garrett GT28. Anything more than 1 bar (14.5psi) and it will be out of its efficiency range, so creating more heat than useful air to create power. And as for boost spikes in the winter, that would be BS as boost spikes only occur when you install a manual bleed valve style boost controller. The MPS will be running an electronic boost comtroller connected to the main ecu. And as for the engine handling 30psi, unless its running forged pistons and rods special valves it may last a few runs at 30psi with a bigger turbo before it starts to melt the pistons and throw a rod. Don't quote me on those figures, as i cannot find them anywhere except from a guy that seemed to have seen it on the net, and also from Mazda 6 MPS owners. ;) "Word on the street is the engine is good for up to 30psi (fully forged from factory) .... and Hiboost is modding a bigger turbo to fit in the standard K04 housing :) The analysist tell me this engine could be better then the boxxer (WRX) for extracting crazy power from ...." gotta wait a couple of days to see my own proof :P HAH! I knew it!!! I knew you'd pour money into it! ;) Be sure to come to the next meet brother!