[Keithc8]

Dyno's can be calibrated and should be checked if you want to keep the machine accurate. You need it to be accurate if you are building race engine to make sure you are getting repeatable numbers. When you are looking for 5 to 10 HP on an engine that is making 800 to 1200 HP already this is very important.
This is done by hanging the same weight on the strain gauge and checking the readings. You also need to make sure that all of your sensors are reading right from temp to borrometer.
Like I have said here several times my Super Stock and Stock NHRA guys know how fast their car should go down to the hundreth and you can not blow bogus numbers up their but. With all of this said you can jack with some things to change the numbers but that does not tell you anything in the end. The dyno is a tool to be used like the flow bench and any fudging will show up at the track.

Good luck, Keith Craft