I tuned my LNF Cobalt SS Turbo about 3 years ago for the K&N SRI and the GM Stage 1. It runs fine, but after playing around with my 2014 Taurus SHO, it got me thinking about the exact gains from the K&N SRI vs stock airbox, because the K&N SRI has almost zero heat shielding - causing it to become a hot air intake in the summer.
I looked at the MAF vs Frequency table, and checked the delta for the tuned values vs the stock values. I saw a maximum of 2.5 lb/min (about 150 lb/hr) difference at the 8-9 kHz region. If we go by Garrett's estimate of 10 hp per lb/min of airflow, that's a maximum of 25 hp. But on my naturally aspirated Mustang GT (4.6L 3V), I'm maxing out around 28 lb/min but it is making well over 300 hp.
On my 2014 Taurus SHO, I see a max of around 38 lb/min at 5000-5500 RPM, 150% load. The engine makes around 365 hp stock, and I saw an average of 36-37 lb/min with the peak of 38 lb/min. But that PID was "Turbo Mass Flow".
But bottom line is that I'm seeing around 0.1 lb/min difference on the K&N SRI up until the 8-9 kHz region, where I then see about a 1-2.5 lb/min maximum difference - and that's it. If this is accurate, then it seems to be me there's not much of a gain with the K&N SRI??