I got the 300C SRT8 dyno tuned today using the Predator. It was a CMR (custom) tune rather than the 93 octane 'canned' tune. It gained approx 6hp and around 20tq across most of the rev range. Using the Predator they also adjusted the shift hardness so now it shifts like it has a shift kit. The power gains don't sound like much but out on the road, the difference is like night and day. The car has much more pull now from down low and the overall performance is much more consistant. Prior to the tune, I used to put the foot down and sometimes it would go quite well and other times i'd scratch my head and ponder if this really is a 6.1.
Peak power after the tune was approx 350hp.