Hi guys, I m writing from Chile..................last weekend I rode my CRF 450R 2013 with Ron Hamp Ported Head + CP Hi comp piston. I added this mods to my original set up that includes Tokyo mods map (for open exhaust) + FMF complete exhaust (dual) + Twin Air Power flow kit (no screen). I m about to report the performance gains of my bike with the addition of the Ron Hamp Ported Head and Hi comp piston. Ride Report The bike is running awesome!!!! • There is plenty of low-end power • Midrange is well improved • Easy to ride powerband • I improved my lap time by 5% (average speed, measure with a garmin and compare with my prior personal best) • The power delivery gives me confidence to open the throttle • No abrupt sudden power hits • I can use a higher gear in tight corners (3rd) • I can hold 2nd gear longer than before So, I m pretty happy with the way my motor runs right now. The track was a sandy tight track, so there was no room to test top-end power……but when I hold 2nd gear pinned corner to corner I can feel the bike revving free. In a few days I will add a Ron Hamp cam to my package, I will let you know the evolution of the motor. I just want to say that I m pretty happy with the setup, the power comes in a friendly and strong way, Ron gave me a very good service, he answered all my dummy questions and supported the whole process of installing the new head. As summary, I just get a big smile in my face everytime I exit a corner and open the throttle. Keep riding!!!. Peak Power.