As for the YFZ450, yamaha claimed it had 40hp, which was rounded off from 38.03, but after many third party tests it is actually 33.08hp stock. Honestly, I'm not sure who's right on this one...yamaha=38.03 or the testers that came up with 33.08? Also, this rating is based on 2005 machines. I'm not aware if the 06 models changed?

 

yes the yfs is detuned from the bike, but with not much trouble you can get the extra 10 hp the bike has

 

Hotdog -

Thanks for the feedback on the GPS!

R'

 

What is the horsepower of a Kawasaki KDX 220r dirtbike? What is the hp of the KDX 200?

 

I have a 06 SP 450. I noticed it was never specifically mentioned when giving the HP of all the engines. One of my Wife's Bro-in-laws has asked me numerous times what HP my Sp is. I had never given it much thought, but would like to know just so I can give him an answer. I am sure it will be very close to the 500. BTW, it is a carb model.

Thanks
Benjio

 

Sportsman 450 = 29.7hp
Sportsman 500 carb = 34.5hp
Sportsman 500 efi = 36hp

Sorry, but I don't know the #'s for dirtbikes. I know a couple, but that's it....

 

Thanks for the info ppope, Good reading.[img]i/expressions/face-icon-small-wink.gif[/img]

 

As some of you have already mentioned, you can't just look at how much hp an engine makes and then decide if it is a better motor. Remember the hp rating is the peak hp, it tells you nothing about how much power the engine makes at a lower rpm. With some engines revving much higher than others it easy to see how some small engines make big numbers. Torque is also easily forgotten with everyone bragging about how much horsepower their engine makes. A dyno can give you a great picture of the powerband of an engine by looking at the torque curve, when the power falls off, and what rpms the powerplant starts making its power. From what I understand, the three things that determine how fast a vehicle will go are power(hp & torque), weight, and traction. My .02

 

The 54.8 hp figure for the 800 with the attendant torque info comes directly from Aaen's dyno test published on their website. The 50hp figure was not an research number to CARB but a published number supplied by Polaris to CARB for certification. These numbers are typically the most conservative actual HP number of any series run and/or are rounded down from any actual manufacturer's research numbers for a specific model or are made up by the manufacturer from other know data. Generally, if you compare the manufacturer supplied number to CARB for certification vs. actual independent dynos you will see this scenario in most(but not all) cases. The truth is you could stick three identical model machines on any dyno and come up with slightly different numbers at the crank and these numbers are not indicative of the performance of the machine due to all the factors mentioned in the last post. A rear wheel/all wheel dyno would be more helpful but not yet perfected for AWD vehicles. Even then weight/traction/tire diameter etc. are still variables to be considered. But since HP and torque numbers are ingrained in us as a benchmark we get to go round and round about them as seen above. How fun!

 

How do you get these numbers again? I have a ATK that has the same motor as the Cannondale. The HP numbers I get are different than yours. I want to know who sold you the line of crap about the 48 HP on the pred. Maybe that is at the crank. When Mine was stock it put out 37 to the rear on the dyno. These are the real numbers for the Cannondale. http://www.atkusa.com/Products450Quads.aspx And if you call and want to talk to the owner of ATK Frank White he will tell you those numbers are to the rear wheels.