Project Harley Dyna, Part 1 – Exhaust, Fuel Management, Air Cleaner
Ultimate MotorCycling Project Harley Dyna, Part 1
Project Dyna is a quick little project bike we have put together with a Harley-Davidson Dyna we had handy.
It is a two-part project, with the motor getting our attention first. To make the engine breathe better, an exhaust, air cleaner kit, and fuel management system were in order. In part two, handling will be addressed.
First, we chose an exhaust. We immediately liked the looks and functionality of the SuperTrapp 2:1 SuperMegs system. Plus, the SuperTrapp features a full flow mechanical core, allowing for a rich, tuned sound, and improved top-end power.
Next on our list was the air cleaner. K&N’s RK Series intake system was an obvious choice. The kit includes everything you need—including a filter and backing plate assembly — to turn a stock air cleaner into a high performance velocity stack.
With the exhaust and air filter readied, we visited John Ethell at Jett Tuning in Camarillo, Calif. He immediately recommended a Power Commander V by Dynojet to make the most of the increased airflow into and out of the Harley motor.
Dynojet has been providing riders with high quality fuel management and diagnostic products for over a decade. We have used Dynojet units on sport bikes in the past with great success.
Stock runs on the Jett dyno revealed a peak of 73 horsepower and 79 ft/lbs of torque. With the trio of mods installed, we put the Dyna to work on the dyno, with the expert tuning of Ethell to make the most of the combination.
Once Ethell was finished dialing in the motor, he made a final run for horsepower. The bike made a hair short of 80 horses at 5600 rpm, and 83 ft/lbs of torque at 4400 rpm. That is a horsepower increase of nearly 10 percent, and a torque boost of over five percent. Certainly, that is some added muscle on the dyno, but the real world is where the performance truly matters.
The Dyna runs much smoother with significantly increased throttle response. The most noticeable improvements are in the midrange, as the throttle response is increased. The motor feels smooth and controllable, powerful without any hesitation.
This is where most riding is done, so the upgrades have a real practical advantage. Of course, the bike now sounds great and has a bit of a hot rod look with the matte black exhaust system and visible K&N. On to Part 2, featuring Progressive Suspension.
Story from Ultimate MotorCycling magazine. For subscription services, click here.