Horsepower figues for 4 stokes?

[BellevegasB]

Anyone have horsepower figures for the following bikes?

XR650R, XR400R, DRZ400E, DRZ400S, YZ426F

I'm looking for ballpark figures, just want to see how they all compare to each other. And why is it that all the manufacturers tend not to advertise their HP figures? You can go to any website and get HP figures for crotch rockets and street bikes, why don't they advertise them for dirt bikes? Thanks in advance,

Ben

 

[BellevegasB]

Got numbers for the 2 Suzukis from Dr. Zaius from one of my other post questions.
DRZ400E 39-39 HP
DRZ400S 33-34 HP
Thanks Dr. Zaius!
How about the other bikes?

 

[BigBore]

XR650R: 49, 50
XR400R: 32
YZ426F: 46, 47

 

[Rodzilla]

The XR4 will hit around 29-32 HP (uncorked) but it's the torque curve thats impressive :D

Rod

 

[BellevegasB]

Thanks for the quick replies everyone!

Ben

 

[Dr.Zaius]

XR650R STOCK rear wheel figures around 43-45hp, depending on elevation. Just uncorking it brings that up to 55hp-only cost is jetting! :eek:

 

[SFO]

Hey Dr. Zaius clean out your pm's I can't pm you.
I would love to see the dynojet files from an uncorked and rejeted xr650 making 55rwhp.
I have the dynojet reader so just the dyno run will work.
Thanks in advance, Bill

 

[BigBore]

Uncorked 650s don't put out 55hp at the wheel.....thats what Honda claims, which isn't measure as RWHP.

 

[SFO]

Originally posted by BigBore
Uncorked 650s don't put out 55hp at the wheel.....thats what Honda claims, which isn't measure as RWHP.

I was confused as the good Dr. says rear wheel hp.
Thanks for the heads up.

 

[Dr.Zaius]

I got those figs from off-road.com. They tested the bike stock, 43hp, and uncorked, 55hp. I suspect these numbers are rear wheel, if it was tested by a place like off-road.com. Maybe I am wrong?! :silly:

Here it is!

 

[BigBore]

ORC didn't actually put the bike on a dyno. They're just re-hasing the info that Honda gave them.

 

[SFO]

Man there sure is a world of difference between claims and running your bike on a dyno.
It is really scary watching your pride and joy spinning a drum...
The first time the computer catches up and spits a # out is like a revelation.
Claims will be somewhat moot and abstract until you see actually what your bike does on the xyz dyno compared to what another bike does.
I learned no one tells the truth unless you see the run and have a operator with integrity.

 

[Syd Mitchell]

Honda U.K. ( which sells totally un-corked xr650r s) advertises that
output is 61.2PS. This is around 62 horsepower and is obviously
measured at the crank. Several Brits, who have supermoto'd their
bikes have reported dyno rear wheel figures of 49-50 horsepower, for
these U.K. standard bikes. Unless there is a big difference in
'merican horsepower from limey horsepower then you guys, once
uncorked of course, should be getting that same 49hp.

Here in the U.K., officially imported xr650r s come with a box of the
power-down parts and road registered.

cheers, Craig

 

[gulliver]

For what it's worth, the KTM 640 LC4 is about 43 - 44hp stock, 48 - 49hp uncorked.

 

[penguin]

my seat of the pants dyno figures indicated that you gain about 7-10 hp by uncorking the XR650R, regardless of wht the actual numbers might be, when you uncork the beast it is impressive.

 

[pontiac]

Here's some interesting dyno info from a XR650R that was built for supermoto.

http://www.supermotech.co.uk/xr680graph.jpg
http://www.supermotech.co.uk/xr680graph_trq.jpg

 

[Whoops]

Since we're opening up the motor...

This week's Autoweek has a story about Dan Gurney's street bike, the Alligator. It's pretty ugly looking, IMHO, but the it's powered by an air cooled Honda 650 thumper, bored out to 710, the cam was replaced, and it's fuel injected. They caim 75 horse power. Hmm....

Whoops

 

[Skid Jackson]

You left out the part that they had $12,000 into that motor!! As in each time they build one they have $12,000 into it!! :eek: I can only believe that they are prorating their research costs into that figure. While i don't know anything about building motors that seems awfully high. What would you spend the money on that would add up to 12k in engine mods?? Thats alot of cnc time, not to mention lots of trick parts!!

 

[Fe_princess]

An air cooled 710 making 75 rwhp has got to have the half life of a billywho bike!

 

[reknelb]

I have an Yamaha srx 600. For those who don't know, it's basically the same as an xt or tt 600. I have a ported head, wiseco 11.5-1 1mm over piston, milled head, valve springs with Tit. tops and retainers, megacycle cam, 42mm flatslide carb, this is a 4 valve head, and it put out 50hp at the wheel. REAL hp #s. I find it hard to believe that an xr 650 with some jetting is going to put out 55, I bet 45 would be pushing it.

 

[Syd Mitchell]

Reknelb, did you read my post above? Off-road.com's test, which the
other guy quotes, is full of it. There is no way a bike with
a factory claimed 62hp at the crank should produce rear wheel
dyno's of 55. Hence the reason numerous Brits, Euros and the rest
of the world are showing graphs of 49/50.

I have added the HRC piston & cam kit to mine and I recon I'm up
to 58 now.

cheers, Craig

 

[helterskelter400]

hate to jam ewe rek but the srx is a yesterday yesterday design. the de restricted au xr650 rorts like no other single yet (i've riden most). its let down fore dirt by its cost cutting coat hanger frrame, spokes, etc when compared with dare i say ktm640's

my o2 !?!

 

[Meatstick]

My CRF piped and jetted does 50 RWHP. Going to mill the head to get more compression so I can run better race fuel. Hoping for 55-60 hp.

 

[PK]

FE Princess,The Honda XR650's are water cooled but even with that, I imagine your right. Can't last too long.

PK

 

[Rich Rohrich]

Originally posted by PK
FE Princess,The Honda XR650's are water cooled

... but the engine FE is referring to in the Gurney alligator is based on the older air cooled XR650L. The cylinder head is heavily modified/redesigned, but 70hp from 670cc still seems fairly high for this design.

Either way it's a pretty interesting concept in terms of vehicle dynamics.

http://www.allamericanracers.com/alligator/alligator_tech.html