2008 Dyno Pull

[Slardy]

"Another option would be to calculate the total reduction ratio from the engine to the drum (including the rear wheel to drum reduction ratio) in a particular gear and somehow configure the dyno to use that ratio to calculate the engine speed from the drum speed. Even if that option is available, I can't imagine a typical dyno operator volunteering to go through the hassle when most people are probably happy enough just knowing what their peak horsepower is. "

I believe that USELESSPICKLES has it right. I spoke to a local Yamaha tech who was running a dyno test when Yamaha had their Bike-Demo-Program in our neighborhood recently. I ask if he produced HP and TQ curves and he said only HP, that he does not hook up the RPM sensor to the engine. I also gleaned from our discussion that he inputs sample wheel size and gearing info which allows a quick and dirty HP curve. The wheel radius and gearing data are what is needed to get a good HP curve, IF you do not have the RPM data. So, if you think you are going to get an accurate HP and TQ curve from a dyno run, you better quiz the tech, as he may, well..., be clueless. You must have the engine RPM and vehicle gearing ratio to accurately produce both curves.

 

[Road_Runner]

Thanks for posting this. It is good to see that the FJR makes that HP that I have read it makes. I did notice one thing that might have affected the numbers... the dyno run was at 12% humidity. Anyone have an idea how much more HP more dense air is good for?

 

[Road_Runner]

After some reading, it looks like the dyno run was a corrected number for barometric pressure and humidity based on the SAE J1349 correction standard per: HP Correction

I beleve that the 1.05 number at the bottom is the correction factor.

 

[GeorgiaRoller]

Whether the bike makes 126hp, 127hp or 128hp is of no matter to me. All I know is that I smile when I WOT it. I guess if your a gear-head then numbers, ratio's and formula's are important.

 

[FJokeR07]

Performance question...

I'm running Holeshot exhaust system (headers & cans), PC III custom mapped by a local dyno whiz...the numbers (graph) he provided:

Max Power = 122.67

Tax Torque = 83.01

The difference after his tuning was obvious in smoothness and the gamma-ray burst that kicks in at about 5K.....but the numbers I've read about on this post seem to indicate that even with my upgrades and mapping...and phenomenal feel....that I'm running on the load-end of this bike's potential?????

I don't know about air box mods so mine is stock except for the K&N...

Comments please!

FJokerR07

 

[carlson_mn]

Performance question...

I'm running Holeshot exhaust system (headers & cans), PC III custom mapped by a local dyno whiz...the numbers (graph) he provided:

Max Power = 122.67

Tax Torque = 83.01

The difference after his tuning was obvious in smoothness and the gamma-ray burst that kicks in at about 5K.....but the numbers I've read about on this post seem to indicate that even with my upgrades and mapping...and phenomenal feel....that I'm running on the load-end of this bike's potential?????

I don't know about air box mods so mine is stock except for the K&N...

Comments please!

FJokerR07

That totally depends on the type of dyno and even the same type of dyno can vary from shop to shop, day to day. What is important is the before and after numbers with your mods. Another person with simlar mods as you (UselessPickles) put down the same hp as you with holeshot headers, aftermarket cans, and a tune. My old 04 with full Muzzy headers and pipe and tune on a Mustang dyno made 118hp and 83tq, and he said it made a "very noticeable" more amount of top end power than other FJR's he had dyno'd. He said his dyno consistently read about 10% lower than a dynojet.

On a side note, I know the humidity was most likely not accurate that night, but the temp was. It was mid-80s outside I know.