This is how I look at it, though it may seem strange to some people. An upgraded IC does two things. Flows better, and cools better. Now, flow should be an issue on the T25 (~20 lbs/min
). But the less efficient and hotter the turbo's outlet temps are, the more critical good cooling becomes, and the greater the gains. It wouldnt surpise me if you could max out a T25 on pump gas with a FMIC. Now, it will add some lag with all that extra volume the turbo has to pressurize, but on a T25 it should still be very quick to spool. Still better than a 14b/SMIC in this regard I would venture to guess.
Dont take my word for it though, try it and see if I'm way off, or near the mark. If its cheap, it cant hurt, and it will be there later on when/if you upgrade turbos. FMIC is a huge part of pump gas power regardless of the rest of the setup.
