Cold air intake
Riffraff Diesel: AFE Stage 2 Si
Riffraff Diesel: S&B Powerstroke Cold Air Intake Kit
Both of them pull from the same location as the stock air filter, so as far as the "cold air" part of the equation, there's nothing special about aftermarket compared to stock. Pulls from the same hole in the same part of the grille. If you're worried about this part you'll have to do the zoodad mod to open up the intake, that will do as much for the stock setup as it will for an aftermarket setup.
That leaves flow and filtration to talk about.
Behind the filter is a vacuum restriction gauge that specifically measures restriction in the intake between the filter and compressor. When you get into some serious turbo/air upgrades, you can actually overpower the stock filter and set off the gauge with just a WOT run. If you aren't moving the filter minder, you aren't pulling enough air to be restricting anything downstream. Basically the stock filter will flow more air than the stock turbo on stock tuning will want to pull through it.
Filtration wise, there are guys who've said they've run 50, 60, 70, all the way up to 100k miles on a single stock filter without setting the minder, because the filter is just plain massive. cheezit, one of the resident techs, always gives the stat that the filter will hold 5 POUNDS of dirt. If you think that some little drop in cone with a third of the volume can do that, go for it, but for the money nothing filters smaller, better, and longer than a correct stock air filter with the blue media. Plus there's zero chance of over-oiling the filter and nuking the MAF/IAT1 sensor.












