Quite awhile back I compiled the following dyno information from the internet to help me understand the dyno process and to understand dyno sheets. Posting for others as I see dynos are discussed frequently on this site. Info may be useful to others.

http://www.land-and-sea.com/dyno-tec...horsepower.htm
http://www.bishopsperformance.com/dynoinfo.htm
http://www.rscycles.com/tech_articles/air_density.htm
http://www.automotiverebuilder.com/ar/eb020534.htm

Many people think that the dyno is the "all knowing, almighty," last word.
Nothing could be farther from the truth.

Dynoing the same bike on different days will net different results. Variables such as air density, air temperature, humidity, dyno operator, dyno calibrations, engine temperature, weight of the tester, tire inflation, tire temperature, tire diameter, gear ratios, correction factors, engine and oil temperatures, type and weight of oil, vehicle mounting procedures, clutch slippage, and the amount of engine break-in or wear can all affect the test. And the most important factor – tuning!!

The dyno is nothing more than another shop tool and is only as effective as the operator, just like any other tool. When used properly it will aid dramatically in performance improvement. If you want to compare your bike to your friend's bike, you will need to go to the dyno together. Dyno charts that are made on different days are not always comparable. This is especially true if there were very different temperature or humidity conditions. Always use the same dyno, under conditions as close as possible to the original run. This means returning when the weather conditions are the same, running your bike at the same engine temperature every time and changing only those parameters you want to test, one at a time. Dynamometers can tell you if you're headed in the right direction, and in some cases represent the quickest way to test a single component. They'll also good at helping you tune an engine for peak horsepower and torque, but a bike that works great on the dyno doesn't always work as well on the street.. Instead of putting all your faith in a dyno numbers, pay more attention to the way the bike actually runs

A well set up, professional dyno shop will usually have a dyno “cell.” The cell is nothing more than a purpose built room with sound deadening and airflow and climate control systems that help control many of the environmental variables that affect power measurements. With a cell, dyno runs can be conducted all day long and good comparisons can be made. Power output can vary dramatically when the engine temperature is above or below its normal operating temperature. A common mistake is to perform a test after starting the engine. The oil and casing may not yet be warmed up. When the oil is cool, the friction losses in the engine increase, causing the measured power to drop below normal. If subsequent tests are made as the engine warms up, the operator might mistake the resulting power gain as the result of some modification. As an engine warms up, it raises the room temperature, decreasing the air density. This causes a loss in actual power output of the engine.

The mere reading of horsepower and torques is almost meaningless (aside from occasional “bragging” rights) in and of itself. But when you want to diagnose a little misfire, see if the engine is running lean in the mid-range, or verify that a cam change actually helped the power-band, you can’t beat a dyno.

The dyno will correct (hence “corrected” horsepower) for atmospheric conditions, within limits but a run on the hottest day of the year and a run during a blizzard aren’t likely to be comparable.

How's it calculated? One common use of the dyno correction factor is to standardize the horsepower and torque readings, so that the effects of the ambient temperature and pressure are removed from the

 

[sm=WTFsgign.gif] was that, a friggin' novel?

 

Why didn't he just say Dynos are the devil? JK

lp

 

man i'm lovin that pic....you da man BH...

dude we are bikers....dont post that much cut and paste please....it was correct to the tee cause i read it, but now i want to beat the snot out of you for makin it so long

 

Da*n that took a half bottle of Crown to finish the read, now I'm drunk can't read anymore

But it was a good info read.

 

Hey Bounty, at least lick your boyfriend's sh**t off that finger first!!!!

 

Is that called for??

 

What do you expect from a guy that writes a novel on his 8th post...wonder what's in store for #10...I can hardly wait! What kinda bogus site is www.southsidesdyno.com ?

 

Dude thats not cool. I see you changed the original post but not for the better.

 

Next time just give us the link, if we want to find out more about the Dyno we can click and check it out. No need for insults and did respect.