Andrew Parker

Fabricated exhaust system incorporating a FlowMaster P/N: 71236, FlowFX muffler.
The custom made FlowFX equipped system weighs 19 lbs. with 2.50" tube through out.
FlowFX has internal sweeping zig zag perforated tube and comes with a sticker.
No baffles are used inside this muffler, It is made of stainless steel and the body is 14" long.

The slightly modified BOSAL OEM replacement system shown below is >20 lbs. But I had removed 7 inches from this to tuck the exit (see weld at end of black painted section) under my custom rear bumper. BOSAL uses 2.00" before muffler and 1.75" after and is baffled internally. You can see the color change in the BOSAL muffler housing were the baffle is located. All that heat will not be hanging around in the FlowFX...

Biggest challenge was figuring bends for clearance over the axle. I used a Speedway Motors 90°, 180° bend-up-tube and cut it up with my trusty Makita 4" disk grinder along with several cut-off wheels. Fitted and MIG-Welded the bits together. Painted the pipe sections with VHT header paint. The FlowFX emblem shows really well through the wheel well when it is installed in the 4Runner. Bent 3/8" steel rod is used to replicate the OEM hangers and this size rod fits the OEM rubber isolators nicely. I used the hole in the end of my biggest crescent wrench handle (hole to hang it on the peg board) to bend the rod while the other end was in the vice. This works really well for controlling the bend and the spring back. For this custom made CAT-Back the exit point is behind rear wheel but forward of the OEM frame mounted anchor point, so it is less prone to getting snagged during technical trail runs. The angle is downward and swept backward slightly like Gen 3's but on the DS. I did have to modify the last OEM hanger but this was to trade the downward length for a more forward horizontal position as the custom rear bumper has a greatly increased departure angle (note notched square port for Hi-Lift insertion).

Bosal CAT-Back vs FlowFX