2007 Dyna Street Bob - Upgrade The Dyna

With a little glass cleaner and a soft cloth, Tony cleaned the muffler and head pipe of all fingerprints and any oils or dirt to keep from staining the chrome once the bike got running and heated up.

Then one more run on the dyno with just the muffler; we got a small gain at 69.1 horsepower and 86.1 lb-ft of torque. Even with the just small gain of power the mufflers sound good.

Next, we wanted to swap out the old air filter with the new Screamin' Eagle air filter kit.

After removing the old filter and backing plate you can see the difference between the two. The new filter is bigger, letting more air reach the motor.

Chris placed new O-rings onto the backing plate. To keep them in place while installing, he used a small amount of Loctite 565.

Here is the new-style integral breather hose that fits in the molded slots on the backing plate.

Next the backing plate was mounted to the EFI using the required hardware. As a service note, Tony recommends that the backing plate get installed with the new gasket. Tighten all three bolts to factory spec, then unbolt all three, and at that time add a small amount of blue thread-locker. Crushing the gasket first will help keep the air filter from coming loose after a few miles.

Then the new air filter and stock H-D cover were installed.

After the last run on the dyno we could see a big gain after adding the air filter to the bike along with the mufflers. Screamin' Eagle stage I kit for EFI costs $140.00. The Screamin' Eagle slip-on mufflers cost $ 300.00.

78.9 horse power and 91 lb-ft of torque.