If i have a HMF slip-on and its jetted,with air box lid on what is going to be the about hp on my raptor 660?

 

stock for the grizzly is 41hp and the raptor has the same motor. so if the hp rating is the same, expect to see 44-45hp with your mods

 

hmm...where did you get that number? Stock Raptors have around 35-38 HP, I assume Grizzly's have less because of the belt drive system, 4 valve head, torquie cam grind, and single carb. I've never seen any dyno chart or heard of anyone getting over 40 HP out of a stock 660, so I donno about that...

I'd say you'll be getting around 40-43 HP, not a bad gain in power at all. If you were to take your lid off and put a K&N in you'd prolly gain around another 2-3 HP.

 

i got my info from my yamaha dealer in rice lake WI. they have their own racing team and they are the only ones in the midwest who turn the 660 into an 800 that puts out 76hp. so they told me the stock grizzly puts out 41hp according to their dyno. it's not that hard to believe when the sportsman 800 is out putting 55hp and the new outlander800ho is putting out 62hp(dirt wheels). the eiger400 puts out 26hp, so the griz being 41 falls right in line with the others.

 

Stock Raptors don't put out over 40 horsepower and you'd be lucky to get in the high 30's, so I find 41 HP very hard to believe, especially coming from a stealership. All your numbers sound a bit too high, but whatever you wanna believe.

 

Stock Raptor 660 is 39 HP @ 6900 RPM's and 53 NM of Torque @ 6900 RPM's. Not sure what the numbers are on your set-up as we would need a dyno to test that out. But i would estimate a 4-5 HP total gain.

 

Mass consensus is 35hp. But what you really need to look at is the gain, as livininvegas stipulated. Take whatever you have, add 4-5 hp.

 

dynoed the other raptor CT exhaust with K&N and thats it, pulled almost 48hp on the dyno.