I don't ever recall KTM claiming those numbers. Sounds like a overly inflated KTM owner.[img]i/expressions/face-icon-small-shocked.gif[/img]

 

......and, I think those HP numbers are AT THE CRANK, not the rear wheels (????).

Crank HP doesn't take into account the drag of the drive train, the weight of the machine, tires, etc., etc......so just because your favorite machine looks good ON PAPER, don't go getting a boner, OK!

 

The dyno we have nearly a thousand runs on now has seen most quads. Stock early 450r's and yfz's were around 35 to 37 rear wheel horsepower (the number that really matters) . The 06 450r's and yfz's were getting close to 50 with the cam mods and pipes . I will be running some race engines this week so Ill see if I can download some charts for the Jap quads. I dont recall seeing anything but Hybrids ,Banshee's and Cannondales getting near 60hp on this dyno. Its a Dynojet with a environmentally controlled room. The nicest one Ive seen. Its at Mikes cycle in menasha WI.

 

Exactly ......

I know the z400 engine makes about 37hp, but only about 27gets to the rear wheels ......

Most sport machines running chain/sprocket on a solid axle will lose about 10 hp through the drive-train. Anything with CV joints is going to lose a lot more, maybe close to twice that much....

The scale of loss really gets crazy on things like Snowmobiles, it takes like over 100hp for a sled to get 25hp to the ground ....

So something like the 62hp CanAm ute, is probably not getting more than 30-35 hp to the ground.......

If you know a physics professor I'm sure you could learn the conversion but it would probably take a month .....

 

With all the CV joints in my quad I loose almost 20hp then, that would put me at about -2hp if I am correct... [img]i/expressions/face-icon-small-wink.gif[/img]

 

i dont know bout stock but my little girl..raptor 660 with 686 and more is gettin 60+ at the wheels, exact # to come latter...all of this at 8500ft.

 

wish they had a power to weight ratio ,

 

A good rule of thumb for power loss is 15%-20% of crank hp is at the wheels for a chain and sprocket, and 30%-35% for a cvt auto with drive shafts. Like a Raptor 700 has about 48hp at the crank, but dyno's at 40 at the wheels, which is a 17% loss. The Outlaw 525 has 50hp at the crank, but on a dyno with correct jettting (very lean from factory) puts out allmost 42hp at the wheeels, which again is about a 17% loss. Then you got to the BRP 800 which has 62hp at the crank, was dynoed at 44hp at the wheeels, thus allmost a 31% loss.

 

But that would make the power to weight ratios out of wack. Shouldn't the BRP be waaaaay slower then? [img]i/expressions/face-icon-small-confused.gif[/img]

(hp/#) = power

Raptor 700........ "40 at the wheels"/396 lbs = .101 hp/per pound

Outlaw 525....... "42hp at the wheels"/395 lbs = .106 hp/per pound

BRP 800............. "44hp at the wheels"/639 lbs = .688 hp/per pound

 

If you just went of HP, then yes, but the 800 has over 50lbs of torque. That is what get's the quad moving.