I've read that in stock trim, the DS450 makes 43hp, although, I believe this is BHP, not WHP. My intention is definitely not to start a pissing match, although I realize it may happen. I have a 2009 DS450X MX with mild BCS port work (no epoxy), two exhaust cams, BCS intake ring with big foam filter, Yoshi pipe, R102L ECU, and green injector. In my experience, the CanAm may have more peak power than the Yamaha, but the power is in a narrower band. This may be okay for riders who are more familiar with the machine, but typically, the Yamaha will perform better for the average rider, being that the power band is spread out over a wider range. This wider power band will be more forgiving in terms of short shifting or over-revving. I have a 2014 YFZR and I feel as though the Yamaha, with just a PC5 and a Yoshi pipe, is about as fast as the CanAm. With my Vortex installed, along with tuning, and an intake setup, and an '08 carbed intake cam, I feel that my Yamaha will definitely run stronger than my CanAm. I haven't had my CanAm on the dyno, as it was already tuned when I bought it, and I had no desire to know the HP and TQ numbers, just for the sake of knowing the numbers. My Yamaha, on the other hand, fell on it's face any time you even looked at the throttle, until I got my PC5 installed and tuned. Now, with all of this being said, depending on the gearing, and tires, and terrain, the machines will likely be very close in performance, as I believe the Yamaha will be more forgiving, but the CanAm will offer more performance if you can access/harness it. The CanAm is also noticeably lighter, which may be of some benefit. The only way to see for certain is to line 'em up... so... get to it. Let us know what happens.