MMR tube is pretty small (3.5") as is the filter. I'd wager sound gains only on it. Never seen an independent dyno or track testing on it.
Wait what!! I was going to jerk myself to one of these on the 21 too
I have the tune required one and using Pmas MAF transfer function if anything fuel trims were showing a tad rich. Car is in closed loop at wide open. It will hit its target commanded a/f no matter what or it will throw a rich or lean code if it cannot hit its target due to fuel trims maxing out. Fwiw there are measureable performance gains on my data logs of my car in both airflow and reduced pull times.
It goes into the fenderwell which I like the idea of especially with our vented hoods but it's a "no tune" intake with close to stock MAF diameter and it's one continuous diameter which means the tube is pretty small compared to nearly all in the market at 3.5" (stock is actually larger at some points). The filter is also quite small compared to others. If they did a bigger tube at least 4" or 4.5" and a larger filter it would be a much better upgrade but would require a tune for the increased MAF diameter.
It cannot make more power by leaning out the car, that strategy won't work on Coyote's, only works on cars that have narrowband o2's as their first o2's. The coyote will use STFT and LTFT to always do it's best to achieve commanded Lambda. That is the benefit of having OEM wideband sensors.
