Maybe if you were talking about eddy current dynos such as Superflow but Dynojets...no way.
Riddle me this, how can putting a carbonfibre wheel on the back of your motorcycle increase your engines horsepower?
It cant, but a dynojet will tell you that it does.

 

Well in theory it could help rwhp by decreasing rolling resistance. Or decreasing how much hp is lost because it's lighter.
Just throwing out ideas here. It is entirely possible. I wouldn't discount the idea without further investigation.

 

I don't own and operate a dyno, but if that is possible it seems either they can be misused, or they are not as well regulated as they should be. Why would a manufacturer make and sell a product like a dyno if they are not uniform and comparable? I expect Harley expends a great deal of effort ensuring each bike is as identical as possible, otherwise they wouldn't comply with EPA.

 

Dyno's are calibrated and operated by humans and as long as that's the case there will be differences in the #'s they produce. This is a fact that is inarguable. GRbrown's point is valid and makes perfect sense, but unfortunately isn't the reality.

 

Too true, and I have heard that there are some tuners "tricks" for manipulating readings so that difference betwween the baseline and end results are increased.

A dynojet only measures the time it takes to accelerate the drum, a computer then does its black magic and spits out a figure it calls horsepower.
Dynojets are so common that they have become the industry standard and force other types of dyno manufacturers into lying to you by correlating REAL power into dynojet hp, after all, who is going to be happy when the eddy current dyno says you only have 100hp and your buddy with the exact same build gets 130hp on a dynojet.

 

Wow this idea went all to $hit good to see that at least the 2 shops can be logical. I for one wouldn't mind a thread about just 98 builds, parts & over all where the TQ hits & what riding styles each person built up their motor for, a look at the dyno sheet is only a small part of the build.

 

Out of left field here... Is it so, that if you have 2 bikes with exactly the same engine, trans, ignition, map etc... Dynoed on the same machine, but one bike has a 300mm rear tire and the other has a 180mm. The bike with the 180mm will show better numbers?

 

The dyno is not measuring engine hp. It is measuring hp to the ground. Yes, other things can determine how much gets to the ground. Which happens to be the most important measurement.

 

If that set up is noticeably lighter, then yes it will, as it has less mass to accelerate.

 

Makes sence. I was thinking more on the 300mm having more friction. So coming back to the carbon fiber wheel, I'm thinking it would wind up faster due to it's mass weight or will it only go as fast as the mechanics will let it.