HEADS UP!!!

Site upgrade in progress... Core site functions are working, but some non-critical features/functions will be temporarily unavailable while we work to restore them over the next couple of weeks.

Please post any bugs you encounter, but before you do, check to see if it's already listed.

Thanks for your patience while we work to improve the community.

Sign in to follow this  
Followers 0
OlaGB

Dyno numbers WR450F, anyone?

18 posts in this topic

Wondering about the real stock power in my european sold WR450F 2003mod, and what some mods could do to it!

Therefor:

Gimme tha numbers! (if there is no similar thread like this posted before??)

Bike:

HP: (write about measuring at the wheel or motor)

NM:

Mods:

This would be fun to read, if there are anyone that actually has dynoed theyre bike..!

Share this post


Link to post
Share on other sites

I put my 01 wr426 on one of the dynos at MMI. I was only getting high 30's, so I pulled the dirty air filter off and got just past 40. My motor has never been rebuilt, and it needs to be, and the only thing done to it is the throttle stop is cut and the baffle is out of the pipe. I had an oring chain and a steel sprocket on too so that didn't help either. I was kinda disapointed, but I understand why it was low and I know what I could do to improve it.

Share this post


Link to post
Share on other sites

Was this wheel hp, or motor hp?

I find info from 38 to 58hp in wr450f on the internet, but it does not stand about it being wheel or motor hp, and no dyno chart to back it up..

It`s not that important, i know, but it is a fun thing to know :banghead:

Share this post


Link to post
Share on other sites

I talked to a company here in norway yesterday, that has a MC dyno room..

They had dynoe`d two different WR450F`s (european standard bikes), and one of them made 46hk, the other made 49hk then changed to a Leo slip-on and made 52hk.. At the wheels of course.. Ha had noted 160 mj on both, but was not quite shure about it being 160 on the slip-on pull..

He also looked at a standard CRF450, and it was about the same as the standard WR450`s..

I ordered a JD kit, and FMF q pipe yesterday and are now wondering about some hotcams too.. I love having that little extra pull :banghead: Not racing anyway, so it does not affect my riding other than making the grin in my face even bigger :banghead:

Share this post


Link to post
Share on other sites

Were all these dyno runs done with knobbies or was a treaded street tire mounted on the rear? I ask because I've been told (and I can't vouche for the expertise of the person that told me) that if you dyno with a knobbie the numbers will be lower than actual. Just curious...

Share this post


Link to post
Share on other sites

Horse Power is a relative term. There is no actual standard for a unit of "horsepower". There are different types of dyno machines out there and they all have a different measurement of horsepower. If you want to compare HP then you need to put the two bikes on the same dyno. Dyno's are a great tool to help tune your bike and to see what gains have been made while tuning but comparing HP numbers can be misleading.

Share this post


Link to post
Share on other sites
Horse Power is a relative term. There is no actual standard for a unit of "horsepower".

Horsepower = torque (lb.-ft.) x rpm / 5250

That is the formula for motor horsepower...quite well defined in engineering terms. There however will be variations in measurement based on things like tires as someone has previously noted. A knobby would not transfer power to the dyno as efficiently as a street tire for example. Also there will be variations in calibration, elevation, temps, etc... I presume every dyno technician has his own preferences regarding bike setup on the dyno and these will all affect the measurement - I doubt there are any accepted industry standards for that. All that said, if you took the same bike to several dynos and set it up on each one the same way, you should get very consistant numbers if the dynos are correctly calibrated.

Share this post


Link to post
Share on other sites
Horsepower = torque (lb.-ft.) x rpm / 5250

That is the formula for motor horsepower. ..quite well defined in engineering terms. There however will be variations in measurement based on things like tires as someone has previously noted. A knobby would not transfer power to the dyno as efficiently as a street tire for example. Also there will be variations in calibration, elevation, temps, etc... I presume every dyno technician has his own preferences regarding bike setup on the dyno and these will all affect the measurement - I doubt there are any accepted industry standards for that. All that said, if you took the same bike to several dynos and set it up on each one the same way, you should get very consistant numbers if the dynos are correctly calibrated.

Altitude and air temperature both make for air density. Denser air (cooler and lower altitudes) equates to more HP. So if your dyno is in higher and warmer air, your indicated HP will be lower. However, most dyno computers will not only give indicated HP and torque curve sheets, but also produce corrected HP and torque curve sheets. Most all corrected numbers are corrected to a sea level altitude and 59 degrees F.

The differences in dyno's are mostly how the operator loads the dyno. How quick it loads up, and how hard they hit it. With that said, different dyno's will produce different results. But, they won't be so different that they can't be used for approximate comparisons.

As the previous poster stated, they are great for initial tuning. You would still want to check your tuning in the real world.

Share this post


Link to post
Share on other sites

2006 wr 450, all free mods, full Leo Vince pipe. With a street tire on a dynojet dyno in a controlled enviroment. mine put out 51.2 hp at the rear wheel. had a 03 yz 450 same set up went from 45.3 before putting the pipe on and it made 49.9 after installing the pipe. In my opinion the Leo Vince pipe is the best u can buy, Yes I have tried fmf ,pro circit,big gun, ect. But for the performance and NOISE u cant get a better pipe.:thumbsup:

Share this post


Link to post
Share on other sites

The motor on the WR 450 is the same as the YFZ quad other than the exhaust cam and piston and they are getting like 45 rear wheel with a pipe, k+n filter with no lid. I'd say an uncorked WR would be about the same. It would feel like more since its 100 lbs lighter but close.

Share this post


Link to post
Share on other sites

Here is the dyno run for my bike, a 2007 WR450F with dirt tire.

Run 002 in Blue is with the AIS kit installed, but no mod to muffler or airbox.

Run 004 in Red is same as above except with FMF Q4 muffler installed.

Run 007 in Green is same as Run 004 except Power Bomb Header installed.

214775227.jpg

Share this post


Link to post
Share on other sites

Just had my 04 wr450f dynoed and the max Hp it said was: 53.70hp up from 49.4hp

Mods when i got the bike was:

  • the airbox was opened up.
  • Staintune slip on muffler
  • I cleaned the air filter Before the dyno, New knobbies

the bike was at stock jetting and tended to stutter alot but the mechanic said the fuel system had water in it which did not help my cause :p But after the rejet and dyno run its a great bike now. Better power delivery through the revs.

all for $250 AUS

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now
Sign in to follow this  
Followers 0