You have to consider that pressurized elements do not heat or cool the same, Like how a higher pressure radiator cap raises boiling point. Water boils at 70* in a vacuum. So there is more here to consider than just temps. Not to mention that any decent filter is gonna act like a velocity stack and inadvertently give the turbo a much wider area to pull air from than just a pipe end or normal turbo inlet. The detonation control alone is very important not only to engine longevity but also if you want to make more power without increasing risk of booom. lol The pipe would also have to stay cool. Remember its attached to the hottest dang thing in the engine, the exhaust, so it is gonna heat up during the pull. The air will have to fight the engine temps anyway. A normal cold air intake is attached to the IM and isn't subjected to the same heat soak.

So... alot of things still to consider here. If all the factors can be accounted for we can get some info.

Some aftermarket parts are bogus, but that's were experience and research come in.