My cousins YZF440 motor makes about 60-65 horse. This is my goal for my DS!! lol.

 

yeah, but to beat him youll need 75 hp [img]i/expressions/face-icon-small-smile.gif[/img] better invest in some NO2

 

SI im getting 2 different opinions here but basically what im hearing is a raptor wont be as good on the track as the 450 even if it were geared lower because of the weight. Its a plus that the raptor has reverse too. Ive never touched sand in my life so the big hill shooting isnt really that important to me. I think i'll get a predator if i can find a used one because the new 450 is just plain too expensive. thanks.

 

dont worry guys, DIRTWHEELS will tell us which quad is BEST! LMFAO!!










BIgger.

 

Yamaha is soo lucky to have dirt wheels their side!!

 

I spoke to a couple of engine builders today that are familiar with the YZ engines. And got the answers that I suspected. The facts are that the YZ engines are very potent from the factory. But they are also pretty much done in terms of power potential. Meaning that they are not gonna make much more power than they currently produce (approx 49RWHP on the bike) in stock form. They come from the factory with 11.9:1 compression and very free flowing ports. Which means they are already on the limits of pump gas and porting will do very little in terms of making more power because the ports/valves already flow more than the displacement can naturally consume. Expect about a 10% gain from an alcohol conversion and little gains from cams and porting because the motors already make peak power high in the RPM band. So 60RWHP is about the max out of the YZF450 that you'll see without going to a power adder (Turbo, Supercharger, or N2O). Since a Rappy can produce 60RWHP pretty easily on pump gas, expect even the nastiest of YZF450 to get it's Butt whooped by most pump gas 686's in any sort of long sand drag.

 

By the way, I only posted this information to help potential sport ATV buyers in making a decision on which new sport ATV to purchase. The YFZ is obviously the better choice for racing MX and GNCC. However the Raptor is still a much better ATV for all around trail riding and duning. And if your tastes run to beating your friends ATV's in a drag race, the Raptor has more potential for power. No replacement for displacement![img]i/expressions/face-icon-small-happy.gif[/img]

 

Given a 200lb rider on each machine, a Raptor would only have to have 67 HP to match a YZF's 60.
YZF with 200lb rider = 550lbs
550lbs divided by 60HP = 9.17
Raptor with 200lb rider = 615lbs
615lbs divided by 9.17 = 67HP
These figures are based on your assumption that the Raptor is 65lbs heavier. As for trail riding, the YZF will require a lot of shifting to keep the power up. Whereas the Raptor's copious amounts of torque will require less shifting and will subsequently be less tiring to ride. Also race suspensions, like the YZF's, are not known for being very plush. I'm sure it will take big hits at speed better than the Raptor, but I doubt it will be as comfortable at cruising speeds. That is the reason that I stated the Raptor as a better trail quad. The Raptor's reverse is also a bonus. I think you just might be having some buyers remorse.

 

No it's just that he knows what he is talking about and the rest of you arn't gonna know what hit you when this quad comes out.

 

I think that it's silly to argue about which is faster until someone actually gets some seat time on the production Yamaha 450. I'm sure that everyone knows that the DS650 motor is based on the BMW F650 Superbike motor. Line up a DS650 against an F650 and see which one is the quickest LOL! It all depends on how much the 450 is detuned, and nobody really knows that for sure at this point. I can't wait to see one run through it's paces, and I hope it lives up to everyone's expectations. Hopefully, the bar will never stop being raised.