does my 2008 Dyna use a GPS chip to calculate speed?

 

No GPS chip. It's Voodoo Magic called a Speed Sensor in the transmission.

 

On my 5 speed the VSS (Vehicle Speed Sensor) is on the top right side of the transmission. Similar to a crank sensor, it's held in place with a single bolt.

 

Thanks! So... If I were to change sprockets on the final drive, the speedo would not be accurate... bummer!

 

Many tuners have a function for speedo correction. Maybe you have one of those. If not, it's a great excuse to get a good tune on the bike.