Who has any tips for getting dyno numbers for a DS. Gearing? Tire air pressure? Seat on or off?

 

Run the gearing that you use most often when riding, and third or fourth gear of the tranny. The dyno will read the RPM and the speed of the drum and correct any needed calculations. Knobbies should be run at about 8-10psi if you usually ride at or around 5psi. You will strapping the quad down, and you don't want the tires any more "squished" than they are when riding. Higher tire presure will create less drag, and less HP loss due to the drag. Keep the seat on, since that is the way you ride it. Removing the seat may get you a little more air, but if your not jetted for the extra air, it could actually hurt your dyno #'s. It will definatly make them less accurate, unless you ride without a seat.

 

The best advice is don't dyno with the stock knobbies,you won't get a true reading.

 

Your right, the knobbies won't be as accurate as a radial tire[primarily due to tire swell as speed is increased], but if the presure is increased, and the rear end stapped down really tight, it will be pretty close. I'm assuming that he doesn't want to buy tires just for dyno runs, like I have.