Cold air intake + turbo (stock config just change filter) no gain, possibly lower.
Reason, Cold air in, heats up by turbo so no point, bigger intercooler is the way to go.
I’m pushing 170 wheel horsepower more than stock with the stock air box, cold air did absolutely nothing.
Once you run into air FLOW issues is there a point, usually when the turbo intake switches from 3″ in to 4″ in is it time to switch.
as for N/A engines, then you start talking, I’m pushing 10 whp more in -26 than +20 and that’s only because of the cold air, you can use a dremel and open up the ducting and optimize it and keep the stock look for the cops 😉
cold air intakes are generally overrated beyond reason and personally I only like them as they are not made to fit one model, can be placed where you want it, takes little space.
Perfect for engine conversions where the stock ducting will not work.
Hope it gave you much info regarding this topi