Was never a believer myself, but happened to pick this one up on a parts truck and since we were already paying for the dyno session why not give it a try? Like I said though, it’s not the “swirl” or vortex or whatever buzzword is on the label, it’s the added plenum volume.
I'd be interested in your results. If it's close to Gramps, I'd say they work. I had a boss once who had a sign on his door "In God we trust, all others bring data!" LOL