Particularly : 1) i want to ask how should i do a dynometer?

for example :        lbs : 2250

                           widht : 195   (cm)

                           aspect ratio : 45 

                           wheel diameter : 15  (inches)

i use exactly the numbers are written above are they correct or should i use a  different measure?

                     2) i also want to ask when should i press the start button at dyno and have i to go fast or easy?

i am rookie on this so please help.

Sory if my English are not good and thanks for the help.