Bolt-on Power

With D&D;'s 2-into-1 Fat Cat Exhaust System

The D&D; Fat Cat 2-into-1 exhaust pipe comes complete with all the necessary hardware.

A look inside the muffler reveals the reason why D&D; calls this pipe high-flow. The overall diameter is 4 inches wide.

If your old flanges are worn and warped, don't worry; the Fat Cats come with new permanent flanges already attached. If you look just below the flange, you can see the step of the header.

We dove right into the installation of the new system after Leroy from Patrick Racing removed the old pipes. Leroy loosely bolted the pipe flanges to the heads after replacing the exhaust gasket on each.

The included muffler bracket was then bolted to the frame rail.

Leroy then slipped on the muffler and tightened down the exhaust stud nuts and the bracket bolts.

To make sure we were getting the most performance possible out of our pipe upgrade, we decided that some jet changes should be made. Leroy disassembled the air cleaner assembly and took the backing plate off the carb. Next, he unscrewed the four screws holding up the float bowl to access the main jet.

The Needle jet holder was removed from the main carb body to facilitate the removal of the main jet.

With a wrench and a standard blade screwdriver, Leroy removed the old jet and after some inspection, he determined the original 190 series jet had been drilled out to approximately 200-210. We wanted to go with a larger jet size and drilled it out to a 210-220 series.

After bolting up the carb and air cleaner assembly, we put the bike on Patrick Racing's in-house dyno to see what the pipes would produce. The D&D; Fat Cats made 4 more lb-ft of torque and 5 more hp than the private label slip-ons that were originally on the bike; plus the new pipes flattened out the torque curve -- and created more power at the low end!

The D&D; Fat Cats add a beefy look to the bike and have a really deep rumble sound. The sound turns a lot of heads when passing crowds of people.

In most Harley circles, people generally feel that 2-into-2 exhaust systems look cooler than 2-into-1 pipes. Over the years, function has begun to edge in on form -- pipe manufacturers have started to appease the public's demand for better low-end power and mid-range torque by making better looking 2-into-1 systems. D&D;'s new Fat Cat 2-into-1 pipe looks as good as it performs.

This beautiful system combines a huge, 4-inch high-flow muffler and stepped headers with gorgeous full-coverage heat shields. We knew the D&D;'s would look good on this '01 Softail, but we wanted to prove they perform. Our test bike was a basically stock TC-88 with some mild jetting and a pair of private label slip-ons installed. We went over to Nigel Patrick's Patrick Racing shop to do the installation and finished it off with a run on his Dyno.