Stock Rap-34.4hp- Yzf Bike close to 50 hp
#1
06-05-2003, 10:14 AM
Join Date: Apr 2003
Posts: 72
Likes: 0
Received 0 Likes
on
0 Posts
Stock Rap-34.4hp- Yzf Bike close to 50 hp
These hp numbers arnt even close, the 450 dirtbike was made to compete with the 250 2 strokes, which are all easily in the 50+hp range, and if you have ever see one of these bikes, you know they rip!! now, how much could yammy really have detuned that hot engine to that it is down 20hp? i dont think so. That bike will SMOKE a raptor...hands down. The only thing i wonder is...does it have reverse? it doesnt say on the site, so i think not, which is good. they did however change th eengine, they put electric start on it, and used the wr engine insetad of the yz, but hey its still a super powerful engine!!
#2
06-05-2003, 11:17 AM
Stock Rap-34.4hp- Yzf Bike close to 50 hp
No reverse and I will personally smack the first person I hear whining about it. This quad was built for one purpose & that purpose had nothing to do with someone too lazy to use one of the many (usually faster) turning around techniques or dismount the bike to back up a little when necessary. [img]i/expressions/face-icon-small-smile.gif[/img]
Here's an excellent write-up on the new quad
YFZ450
Here's an excellent write-up on the new quad
YFZ450
#3
06-05-2003, 11:26 AM
#4
06-05-2003, 11:30 AM
#6
06-05-2003, 12:43 PM
Stock Rap-34.4hp- Yzf Bike close to 50 hp
Guys,
If they used the WR-450F motor, the May issue of dirtbike has a review on that bike.
They said that the stock exhaust (which may or may not be the same) is very restrictive and that GYTR has an accessory baffle to open it up. They also said that there is a WR specific throttle stop that needs to be replaced with the YZ throttle stop in order to allow it to run at WOT. Also, some people cut the Throttle Postion Sensor wire b/c that advances the timing at low RPM. They also said that the cams are different from the YZ and it has a heavier flywheel and has more controllable powerband than the YZ.
They performed these mods (I know the GYTR baffle but not sure about the throttle stop but I imagine that they did) and it produced 45 HP. The KTM450 EXC dynoed higher at 46.5 or so HP.
If they detuned the motor at all for the quad it will probably put out 38 or so stock, right around a stock Rappy. I doubt very much that it will be 50HP or so stock as some are speculating, but maybe?!?!?! It should be interesting to see, that's for sure but it looks to be a real winner on the MX track.
Good job Yammy!!
If they used the WR-450F motor, the May issue of dirtbike has a review on that bike.
They said that the stock exhaust (which may or may not be the same) is very restrictive and that GYTR has an accessory baffle to open it up. They also said that there is a WR specific throttle stop that needs to be replaced with the YZ throttle stop in order to allow it to run at WOT. Also, some people cut the Throttle Postion Sensor wire b/c that advances the timing at low RPM. They also said that the cams are different from the YZ and it has a heavier flywheel and has more controllable powerband than the YZ.
They performed these mods (I know the GYTR baffle but not sure about the throttle stop but I imagine that they did) and it produced 45 HP. The KTM450 EXC dynoed higher at 46.5 or so HP.
If they detuned the motor at all for the quad it will probably put out 38 or so stock, right around a stock Rappy. I doubt very much that it will be 50HP or so stock as some are speculating, but maybe?!?!?! It should be interesting to see, that's for sure but it looks to be a real winner on the MX track.
Good job Yammy!!
#7
06-05-2003, 12:57 PM
Stock Rap-34.4hp- Yzf Bike close to 50 hp
From: ATVNews.com
Though the new Yamaha is called a YFZ, the bottom end is actually closer to that found on Yamaha’s WR450F off-road...
As compared to the WR bottom end, the gears in the quad are wider (for durability) and the cases are redesigned to accommodate those gears. The crank diameter has been reduced and the stroke is shorter. Many other components on the quad motor are straight from the YZ motorcycle.
...For good top-end response, the intake cam is from the YZ motorcycle and, for the strong torque a quad needs, the exhaust cam is from the WR motorcycle.
-----
COOL [img]i/expressions/face-icon-small-happy.gif[/img]
Though the new Yamaha is called a YFZ, the bottom end is actually closer to that found on Yamaha’s WR450F off-road...
As compared to the WR bottom end, the gears in the quad are wider (for durability) and the cases are redesigned to accommodate those gears. The crank diameter has been reduced and the stroke is shorter. Many other components on the quad motor are straight from the YZ motorcycle.
...For good top-end response, the intake cam is from the YZ motorcycle and, for the strong torque a quad needs, the exhaust cam is from the WR motorcycle.
-----
COOL [img]i/expressions/face-icon-small-happy.gif[/img]
Trending Topics
#8
06-05-2003, 01:02 PM
Stock Rap-34.4hp- Yzf Bike close to 50 hp
Good info.
Dirt Bike also said that to get more performance from the WR-450F that you could "replace the exhaust cam with one from the YZ". I take that to mean that the intake is the same on the YZ, WR and the new quad but that the WR and quad share the same exhaust cam.
Looks like the dyno numbers may be close to the bike!
I'm glad I've got a 686 so I can outrun the new Yammy 450!!! Pretty crazy!
Dirt Bike also said that to get more performance from the WR-450F that you could "replace the exhaust cam with one from the YZ". I take that to mean that the intake is the same on the YZ, WR and the new quad but that the WR and quad share the same exhaust cam.
Looks like the dyno numbers may be close to the bike!
I'm glad I've got a 686 so I can outrun the new Yammy 450!!! Pretty crazy!
#9
06-05-2003, 01:07 PM
Pro Rider
Join Date: Jun 2002
Location: Liberty, West Virginia
Posts: 1,258
Likes: 0
Received 0 Likes
on
0 Posts
