what is the true top speed for an raptor i have read the top speed is 68 71 74 mph I have read this in 3 mag. and what is the hp.

 

The ragazines don't provide accurate readings, their all sellouts to the ATV companies.

Heres what my dealer has recorded on a stock 2000 raptor 660R

Horsepower=38.1 at 53mph

Top Speed=77.8mph at 18 horsepower

These were reading off from a Dynojet chassis dynamometer it is an inertia type chassis dynamometer.
What it means is that it calculates horsepower and torque based on how quickly the rollers move in a given inertia, in this case, a set of rollers of a given mass and dimension is accelerated.
The length of time it takes to accelerate from one rpm level to the next is the sweep time and the rate that you accelerate from one rpm to the next is the sweep speed or sweep rate. Cuz it takes more power to accelerate the mass faster, you will see lower horsepower figures when an atv is tested in a lower gear. This is cuz at higher speeds and higher gears, it takes longer to accelerate from one rpm level to another for example, 2000 rpm to 6000 rpm.
This stands until the gains in horsepower from increased sweep time are offset by the increased frictional losses of the gearbox, gearing and tires.
As speeds increase, the frictional losses in the gearbox, gearing and tires increase. The higher the horsepower of the atv, the faster it will accellarate the roller and the higher the speed will need to get the sweep time long enough to give an accurate reading. Cuz the Dynojet chassis dynamometer is an inertia type chassis dynamometer it does not allow you to perform fixed rpm or step type horsepower tests you can not hold the atv at a given rpm or speed and check the horsepower level.
The inertia type dynamometers gives you a very accurate measurement of what the atv see's in "real world situations". An inertia type dynamometer will show the effects of reduced weight such as lightweight flywheels, gearing and wheels while a steady state test does not show these improvements.

2000 SCRAMBLER 400 2X4

SCRAMDADDY400

 

My Raptor ran 75mph when it was bone stock, and this was at a track, not some riding beside my friends truck BS, and the stock HP is about 33-35 to the rear wheels, and about 35-39 at the crank

 

Nice Cut and Paste

 

"Bone stock Raptor. Ran a 15.02 at 76mph in the quarter mile at Red River Raceway in Shreveport La" That is a quote from a recent post in this forum.

 

I don't know how fast I was going on the frozen lake today, but I do know that I was going so fast, The ice was melting underneath me and The visor on my helmet blew off, then I passed a 400ex and blew the stickers off of it. That's how fast the Raptor is. Hey, this forum needs some humor in it.

Chasman
01 blk/wht raptor
Big Gun Exhaust w/ dynojet jet kit
whole bunch of other stuff

 

Hey that was me!Actually Mine ran 75mph, my friends ran 76 with me on it.Now we have the same pipe, gearing and jetting and he is still about 1mph faster than me.Lucky chump, he got the stronger bike from the factory, or maybe the Black and white ones are just faster

 

I noticed a screw missing out of my visor.. I guess that's what happened to it....

Hey no2stroke, what mods do you have? and what's your jetting?

 

Your right I did cut and paste it, from the question about dyno's topic above. I wrote it there and cut and pasted it to here.

Good observations..........****bag.

2000 SCRAMBLER 400 2X4

SCRAMDADDY400

 

No2strokebs I am not implying in any way that you are not a good rider in any way from this post so please do not get offended by any of this post. On the quarter mile there is a lot more than just this quad and these MOD’s will make this many hp or top speed there are lots of things that can change and remember that you said a 1 mph change and not even tenths so you could only be .1 mph slower, a large thing that changes a lot of times is if it is jetted right, but when you are side by side, same mods, same jets it should not be a prob. but if your air filter is not as clean or you used a different oil for that matter it could change also you could have some mud in your snorkel that makes it less Aerodynamic. And also how you break in a engine can change performance or maybe you have more carbon in your exhaust pipe, silencer, valves, or a some stuck on your piston making it weight more and more mass to move will make it harder for the engine to rev and move for that matter. Or some different oil that is thicker and it is harder for the engine to move or colder oil would be harder to move. Also i guess the cluch plates could be worn and have less weight. The tires tread could be worn more on one than the other and be less aerodynamic or ones tires could be more flexible and be larger (taller.) then one may have lots of scratches on the plastic or not clean. And then there is the weight issue if one weighs more. If one rider sits higher than the other and could less aerodynamic or if you were riding in mud or water the rider or quad could have more mud on them/it and weigh more or one has more gas in the tank. (Remember were are talking about one MPH or less). Now all of this is just what popped in mind and although some things would not very much difference they can add up. And the rider is the biggest differences like if they shift at the same time (rpm).