Has anyone installed a Donaldson Filter Minder on their SHO airbox? It's one of those vacuum operated devices that measure the restriction post-filter to help determine when the filter needs to be changed. They are generally standard equipment on heavy duty vehicles and some OEMs use them for light duty pickups. They are on the instrument panel for HMMWVs, and generally the diesels have the 0-25 inH2O gauge and gas engines have 0-10 inH2O.
I can install one very easily I think, but I'd rather not drill into a $40 airbox lid if someone else already did testing.
I've seen independent testing of drop-in filters tested at 28 inH2O and the dry filters generally barely outflow the paper filters (e.g. AEM, AFE) and the oiled gauze filters flow more. The Green Filter is the worst in filtration and outflows the other filters (not surprising).
Based on what K&N told me about the max flow for their 33-2395 panel filter, they point to the airbox as the restriction when you tune the SHO. There would be a restriction, making the turbos work a bit harder to maintain the demanded boost.
