Heres what went down yesterday, my kfx-450 (yoshi) , my buddys yfz-450 that has gytr exhasut, open airbox, proflow, K&n, 170mj, 45pilot, third or fourth clip on the needle and my other buddys kfx-700 with full yoshi exhasut, K&n , that was jetted on the dyno got our quads dynoed yesterday. Unfortanatly my quad is still not tuned as it should since it was shooting flames out the exhuast upon backfires, but my jetting right now is 195mj, 45pilot, and stock needle. We were all running Nobbie tires on a motorcycle dyno that was modified for quads. The numbers went as followed:
Kfx-450 (Yoshi) = 39.6hp / 31.4 ft/lbs TOP SPEED 85mph
Yfz-450 = 36.1hp / 24.7 ft/lb TOP SPEED 73mph
Kfx-700 T=35.5hp / ??? TOP SPEED 75mph

 

24.7 ft/lbs for the YFZ? My Z with just a slip-on, filter, no lid and jetting has 23.6 if I remember correctly. Of course my hp #'s were alot lower..............[img]i/expressions/face-icon-small-sad.gif[/img]

 

sounds low and slow for the yfz

 

well he was running knobbies too. with slicks u can add a few more hp to each

 

mine was run with knobbies also...........

 

Well all I have to say is that all dynos are not acurate. But I do believe your 450 is faster and more powerful than both.

 

More fun in the zuki forum:

Dont take the dyno numbers at face value. The only good those dyno runs are is to compare them to each other. The quads were all run on the same dyno under the same conditions so they are comparable to each other and nothing else. These runs let you see how much more power MURDR is making compared to the tested yfz and Kfx. Dont compare the numbers to what you think they should be because your opinions are just that. They were formed by forum/public consensus or your experiences on a different dyno on a different day with different testing and weather conditions. Therefore they are not comparable.

 

Yeah what he said.

To me a dyno is mainly a tuning tool.

I raced MURDR at silver lake(before Hotcams and base gasket), the Yoshi 450 definetly gets it.

 

sweet...now dyno my eiger and my mojave...oh and i want it done for free...lol

 

This guy is right.... dyno numbers mean nothing except in comparison and tuning. They are only comparable if taken on same dyno, same day, same conditions, same tires. They are great to use an 02 sensor on, running through the rpm range. Dyno's are the best jetting tool possible.

Sounds like that dyno is not very forgiving. You should be looking more around 45 for you and a little less for the yfz. I hope you used an 02 sensor to make it worth it, and jet accordingly. Nice comparisons anyhow. Way to put a whoopin on the 450 and 700. I hope to get the yoshi kit ASAP.