I ran a 15.3 on a N/A setup on my homebuilt Type-R motor, my '97oBDII b18C1 with a '99 si head with USDM Type R pistons, CTR Intake Cam, and ITR Exhaust cam. I had bent exhaust vavles on cylinders 1 & 2. 1 is completely dead, pull the spark plug wire out, and no idle change, and 2 isnt' so bad, but not by much...I gotta take a photo of the timeslip... :twisted: Rebuilding the head next year 9,000rpm's here I come...