This graph shows part 2 of our multi part performance upgrade dyno test of a stock 2005 Harley Davidson Duece. This part add's a K&N 1499 stock style replacement air filter along with the NGK Iridium Spark Plugs that was added in part 1. Dyno testing shows another dramatic gain in peformance after it's installation.  This bike has not been tuned yet and the only other modification is a set of Vance and Hines pipes that were on it to begin with.