I've tried a Vic Jr on mine twice,,,two weeks last spring with no improvement and just a couple weeks ago. I lost 60ft., e.t. was off, picked up a little mph, put the Performer RPM back on... 60ft came right back,set an all new best e.t. and set an all new best mph in 600ft worse air. I shift mine at 6k, kind of a self imposed deal, I want it to last as long as it can, would like to get 2-3 yrs out of it anyway. I'd go for an RPM Air Gap, and would love to try the RPM for rectal ports.