Me and my buddy got our bikes dynoed today! My bike is an 09 KLX250S with a full muzzy exhaust, uni air filter with no lid on, pilot jet is 38, nt1c needle at the 4th notch from the bottom and and keihin 138 main jet. My buddy's bike is a completely stock 08 WR250R. His bike used to smoke me until I did my mods! Now the only time he would pull away is at around 65mph. But then again, his bike is stock and has a lot of potential! I'm glad I got to see my air/fuel ratio. I was running very rich midrange and at top end!

Here are the results for my KLX:




And here the results for the WR250R:

 

Here's the video of the KLX on the dyno!



And here's the video of the WR250R on the dyno!

 

As you guys can see, the WR is pretty powerful in stock form! But if you look at the torque differences, it's not much! I love the way my bike runs right now but it will get better once I get the jettings right! I love my bike!

 

Anybody have a good link or report that explains the difference and relationship between horsepower and torque as it relates to any performance motor?

Or feel free to profess. Class is in session and I am ready to listen.

Which is better more HP or more torque?
Why?

Thanks.

 

Thanks John.
Nice pics and great info and great vid.'s

Wow that Yama-mama is a strong stock bike!

 

Funny that you posted this as I was talking with my buddy who owns a DR and was wondering how much power/torque this bike actually puts out. Granted mine is bone stock but it's nice to have some sort of idea. I'd take the KLX over the WRR any day of the week!

 

Someone close to me advertises dyno runs for m/c & atvs for $40. Does that sound about right? Never done it before and wondering how much does this bike put out with the pumper carb....

 

$40 sounds about right! Today was free dyno day at Orange County Motorsports. I'm not sure your pumper carb will give the bike more power, just better throttle response...maybe I'm wrong?

 

Torque and HP are directly related.
HP is torque x rpm.
Torque is rotational pressure or force.
HP is this force x rpm, how many times this force is applied per unit of time.
Both are important.

When the piston is forced down this linear force is turned into a rotational force at the crank and is then transferred to the back wheel. This is torque.
As the revs build up the rate this force is applied increases. This is power.

Which one is "better" depends on what you are trying to do.

A motor that develops high torque but can't develop high rpm. a diesel for example, will be good at moving a large mass but not really any good if you want high speed. Great tractor, poor dirt bike.
A 2 stroke for example develops relatively low torque but is able to develop high rpm to compensate for this. Great race bike, poor tractor.

Modern 4 stroke dirt bikes are a great compromise.
They use light components, short strokes and good engine balancing enabling higher rpm and therefore high power and, good torque.

Our KLX is a relatively old design and doesn't, by modern standards, develop high rpm.

 

great explanation neil
nice to see some real results, is the extra weight worth the extra horses, i doubt it