I'm running the Piper Stage 2 cams, and especially for those with the 2ZZ engine but needing to keep the Celica ECU (i.e., the OBD II) for emissions compliance concerns, this would be at the top of my list of mods. It really wakes up the small cam. I ran NA to break in my stroker engine before hooking up the Rotrex and PFC, and IMNSHO, if Toyota had produced a Spyder S model with a 2ZZ stroker engine, the Piper cam grinds and with a more aggressive ECU tune, they could have carved themselves a nice slice of the Boxster/S2000/350Z pie.