450 HP Numbers

The 3 speed worked fine. It was the 70 hp part that "could have been a lie".

The 3 speed worked fine. It was the 70 hp part that "could have been a lie".

true, but you have to believe those factory bikes, or close to are putting out some SERIOUS numbers...

take for instance, burned has a 450 thats making what, 60 HP?

true, but you have to believe those factory bikes, or close to are putting out some SERIOUS numbers...

take for instance, burned has a 450 thats making what, 60 HP?

His bike is a Super Moto rig. It's a lot different than what you need for an MX bike. If you combined all of the straightaway sections of major US national tracks where you could use that kind of power, it would possibly add up to as much as 300 feet.

Not 70. No way.

i dont see the problem with a 3 speed for racing. with 70 horsepower i think you could start in 3rd, and keep it there for the race. unless im missing something :banghead:

The bike didn't have 70 horsepower.

At that rate, Ferry's arms would be Jell-O in ten minutes of racing. Not even RC could handle a 70 horsepower works bike, its just to much power for the motocross track. I believe it was MXA that tested the bike, and they said the 450F was CAPABLE of horsepower numbers in the range of 70.


Did you ever get the dyno file that I sent you? I sent a 2nd one that wasn't zipped.

yes,but something is wrong with the file.try to resend it.

just to clarify,there are crf's with my same motor combo being motocrossed.its very easy to ride with a very wide torque curve,not peaky at all.rev or short shift.works either way.

over 50hp for 4,000 rpms.just picture it in your head. :banghead:



hmm, wierd. im going to send it again. thanks.

got it.winpep 7 will not open it.i will try to find my old copy of winpep 6.

You da man, burned. If there's anyway you could find me a copy of winpep 6 as well, that'd be awesome. :banghead:

Those dyno numbers seem high my 03 450 with a cut head,ported,piped,jetted,carb mods etc pulled 50.3 hp on the dyno. We had a 05 yzf 450 also there 45.0 hp on the dyno. If I played with the jetting some more and ran U-4 fuel maybe another hp or two but really to start getting big numbers is pretty stupid. My motor makes a ton of torque more than the stocker and starts at like 2000 rpm. Its really arm pulling out of the corners. You should really be looking at the torque values not the hp, torque wins the races not hp. On paper it only has 5 more hp big deal but the torque is crazy and when you drive it you can notice it. I have the sheets if you want to see.


let's be clear: lap times win races. Horsepower and torque won't necessarily lower them.

this is true. Although a buddy of mine has a mod CRF450 with a high-comp piston, ported head, and I believe they decked the head. He was only putting out something like 47hp but like 45ft-lbs of torque. How could my dyno be that far off? I talked to a guy in the area that I believe works/tests dynos and he said that the MMI dynos are actually very accurate. I didn't mess with winpep 6 at all, I just pulled everything up and ran it. Guess I just don't understand them enough. I know that there's like a mini weather station inside the room that figures out the temp, etc. and I thought it automatically put it into the file? I know that the dyno was very accurate for other bikes (ie GSXR750 with a full yosh put out 133hp and an stock sv650 put out like 71hp) :banghead:

P.S. Burned- Did you ever happen to find another copy of winpep 6?

To produce 47hp with 45 ft/lb torque, he would have to have produced that horsepower at 5465 RPM. That would be something of a torquer. You may be missing the fact that the peak horsepower occurs at a higher RPM than the peak torque. 32 ft/lbs at 9000 would be 55 hp, for comparison.

Torque = (HPx5252)/RPM, or

RPM = (HPx5252)/Torque, or

HP = (torque x RPM)/5252

Well I don't know of the EXACT #'s but it was something like that. Torque was just a tad lower than his HP.

Burned- the CF, temp, etc. is entered in automatically in winpep 6. Here is my conditions. This is a different run than before.


28.6-0.51in HG

CF = 1.07

Max Power = 56.2

Max Torque = 38.1

On nitro maybe you could get 65- 70 HP but who cares tourque turns the earth anyway!

that dyno just reads high. sv 650's make 60-65hp on my dyno.

Well a stock YZ450 put out 46 or 47hp on it the other day so I wouldn't say that it just puts out high numbers. I honestly think that there's some kind of motor work done to my bike (bought it used). I'd have to take it apart and find out. Not to mention I talked to a guy that tests dynos in the area and said that MMI's dynos are some of the most accurate dynos in the area. :banghead:

All that HP does ya no good unless ya hold the throttle on.


the only way a 450 is going to make 70 hp @ the rear wheel is if the intake port is made considerably larger in cross section and that would require a new casting and a much larger carb .bikes like Burned's produce very smooth power with a flater curve theres no abrupt changes in the power i have had to deal with this on the dirt ovals for years trying to reduce wheel spin these same engines work on mx tracks most of the engines im seeing by other builders have an abrupt hit on the bottom and poor over rev and there dificult to ride just like a cr 500 .

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