I dont know how to say this without getting someone mad at me but beyond tuning your own engine etc the numbers from a dyno are close to useless. I say that because an experienced operator can "tweak" things to change the results more than swaping pipes etc.

So now we dont only have to expect different results from things like elevation, temp and tuning but also have to trust the honesty and experience of the operator. Now combine with the needs of the company running the tests and how they could influence the operator or results also.

If you can get thru all that "trust" stuff then get something that you can use but still have to know the who what and how to adjust for the ones you can trust like temp.

I remember looking at some charts on FMF's site on the 400ex. Of course they needed to show how their product added hp etc and I cant argue or defend their numbers since I didnt witness the tests etc, but after looking over all the info it seemed strange that though the various pipes tested all showed a improvement over stock in that exact test there were other tests done that showed the top hp to be listed at the same total for aftermarket and stk. So thats how much the other things can change the numbers.

 

I guess I looked at the dynos wrong, however stock for stock hp looks very close. 42hp stock on a yfz, sure doesn't look that way with stock tires.

 

Don't let #'s on paper discourage you guys. In reality both 450's, the raptor, and even the DS650 don't break 40HP at the rear wheels, plain and simple. The DS650 puts about 39HP at the rear wheels in reality, not to mention gobs of torque. The raptor is about 38, etc. I have the magazine at my house right now that explains the DS650 before it was introduced to the world, and they promised 50HP at the rear wheels.... These #'s just arn't realistic and are just lies. But the point is, go and RIDE a yfz450, raptor, ds650 and that's what 36 to MAY BE 40 HP feels like... I'll tell you right now, it takes A DAM IMPRESSIVE quad to break a REALISTIC 50HP. And a REALISTIC 50HP quad would run frickin circles around a DS650 like mine, and any piped and jetted raptor, 450, etc. But you're not gonna find many people that are honest about HP #'s. For example: Over 75% of the piped and jetted Raptor owners claim their quad puts out about 50HP, and I'll tell you right now that it's pure bull$hit!! Like I said, a quad with an honest 50HP would make ANY PIPED AND JETTED quad look ABSOLUTLY STUPID in a race. I know of people with DS650's that have a pipe, jet kit, filter, high compression piston, cams, ported and all that good stuff that only dynoed 45-48 HP, but it still made the person that claimed their piped and jetted Raptor made 50HP look SILLY!!! All I'm saying is HP #'s will fool you and people and companies will highly exaggetate HP #'s to lure you in to make you think it's got that much power, but reality says otherwise.

And for the people that wanna know the difference in power between the soon to be Honda 450R and the Yamaha YFZ450.... DO ANY OF YOU GUYS GO TO MX RACES!?!?!? Watch the the crf450 powered quads against the yamaha 450 powered quads or the yfz450 itself. From my experiance by watching these races I'll tell you guys a few things. The yamaha 450 motor revves quicker and has quite noticably different power band than the Honda 450 motor. The yamaha 450 motor has more of a "2 stroke like" power curve. Not quite as much bottom end power and not as much torque as the the honda 450 motor. It don't have the smooth power delivery like the Honda 450. The yamaha 450 motor revves higher and has a hit like a 2 stroke. If you ride both the yamaha 450 powered quad and the Honda 450 powered quad most will say the Yamaha 450 powered quad "feels quite a bit faster" than the Honda 450 powered quad because of the power burst in the mid range and incredible top end. But that doesn't mean it wins races. In all honesty, the mid range-top end hit of the yamaha 450 make it harder to ride and make it more prone to spinning which causes more fatigue during a race if you really want to get down to it. The honda 450 has smoother power and more torque in the low-mid RPM range and even though the Yamaha 450 seems to have more top end power, I see more of the Honda 450 powered quads winning the races. And I believe it is because of the smoother power delivery and more torque. This is just what I see and if you wanna dissagree that is fine, but I don't come on here to tell you lies about what I see and report. And it's not like it's a brand loyal biased opinon.... I don't own either Honda or Yamaha so I wouldn't lie about it......

 

Hmmmmm....... Here's my dilemna- I currently have the 400ex and I'm looking to upgrade. I have a 100 deposit on the trx450r, but want to make the right decision between the trx450 and the yfz450. For the dollar investment between the 400ex and the other two quads, I really want to get my money's worth. I like the 400ex's handling capabilities, it just doesn't have the power that I want for acceleration and launching off the dunes.

The initial HP numbers appear to be a little disappointing, but as others have said, this can be very misleading.

Here are the deciding factors for me. Any light you guys can shed would be appreciated.

1. I'm 5'10 235 lbs
2. Not as concerned with top speed, however I would like to be able to accelerate to 60MPH fairly quick. (I've actually tested with a GPS, and 60MPH on a quad is pretty fast, fast enough to kill you,) I just don't want to take all day getting there.
3. I do some trail riding- once every few weeks, but I really love the dunes. Plan to ride the dunes alot next summer.
4. I like catching air, not big air yet as a novice, (3-4 feet high over 50 foot) but would like to get some 6-10ft air without having to have the bike rapped in 3rd or 4th gear hitting the jump. (mostly jump at the dunes as well)
5. Small possibility I may do some 30+ (I'm 30) beginner racing for fun next year.
6. Drags are nice, but not the deciding factor.
7. Looking for an overall powerful quad that will haul axx, jump and handle well in multiple environments.

I've kinda seen what the YFZ can do, videos, people racing, jumping etc. But have yet to ride one. Sitting on one, the ergonomics feel slightly more cramped than the 400ex. Maybe I'll go test drive one today, only problem is that the test drive is very limited in finding out about the quad. Of course the 450R is not out yet, the reviews sounded good, but how much of that is hype.

I'm Still fairly undecided at this point. Appreciate your thoughts. Looking to get the best bang for my buck.

 

Maybe at the crank but the HMF numbers are REAR WHEEL -- Big difference....

 

learning2fly, Both 450's will be very close in every catagory. Like Ridley said, either quad will go faster or be better than the other depending on how much $$$ is stuck in it. Both will be great quads, so what color do you like better? red or blue? Do you wanna have to kick it over to start it or would you rather have the magic button?? That's about it for the "what's better" controversy.

 

A couple things.

A guy with a bone stock 2004 CRF450R rode my YFZ today. He said it was AMAZING, loved it and wants to buy one. He said the top end was definately stronger, by a lot, than the bike. The bottom end is close, but he liked the bike a bit better on bottom.

Then another friend rode my YFZ and was just flabergasted. He has a 2002 CR250. The best one I've even seen run that's not racing professionally. A lot of guys have commented the same. He has a ported jug, pipe, reeds and air filter with a fresh top end. He said the CRF450 was a lot stronger on top even though we all though the 250 was the shiznit. He thought iot had a good 8 more hp than his modded 250. Then he got on my YFZ and it blew him away. He also wants one, and said now he can see why I like quads.

Dynos are only a tuning tool, yes. But both bikes run on the same dyno by the same operator makes it a vaild test.

Two guys over on the " other forum "are making 54.5 and 55.X RWHP with a stock bottom end and bore on their YFZ's. One has head porting with a pipe, filter and cam mod, the other has the same stuff but no ported head and a 13:1 piston. They used stock tires pumped up a bit I believe, for less drag.

I believe the stock YFZ is good for 37-39 RWHP stock regardles off what some testers get. 50 IS a ton, yes. Hard to do on almost any quad in any situation. When you get there, it's not likely you'll lose many straight line races.

I disagree that a high revving quad makes it spin more. Torque will break the tires loose even easier. It should also get you out of the corners quicker if you can hook it up. The YFZ does hook up does not hit the power band anywhere near a 2 stroke Banshee where you just blow the tires off. In any race when there is a bit of distance between turns and is more open where you can let the motor shine, good luck beating the YFZ. If it's a smaller, tigher course, then good handling and stump pulling torque can be relied upon to do most of the work and win many races.

 

I'd have to look again, but doesn't Yamaha claim about 46 at the flywheel, down about 9 from the bike?

 

Oh, and what have we here. A quote from the CR250 guy today that rode both the bike and YFZ I talked about in this thread.

"Ok, heres the deal from a completely unbiased red rider. Today, I got to ride a
CRF450(bike, 50 tooth sprocket as mod) and YFZ quad (see Barely Legal's sig) within a few minutes of each other. The CRF450 on a 220lb frame is extremely agile and fast and is a great bike. Given the extra 130lbs the quad had, there is NO question in my mind that a neutered Honda 450 engine on a quad is going to be murdered by the Yamaha. That engine flat out screamed. Very impressive.

There you have it. Straight from the Honda guy's keyboard."


'nuf said.

 

The yamaha 450 motor is superior to the honda 450 motor. No ifs ands or buts. Those few missing HP will be expensive to get. I am a bit surprised that it made 34hp i was figuring 32. The honda will be a very good quad but the yamaha 450 is much better all around. I wish honda would put the same effort in the quads as they do the dirtbikes/cycles/lawnmowers.