The Ford Lightning is a good example of the necessity for a quality testing procedure. At first glance, you would think that the 5.4L Lightning would benefit from the same mods as the 5.4L F-Series - Not True. The Lightning performed better when configured with 2.5" mandrel-bent tubing than it did with 3". So, even though it looks smaller than the F-Series system, it kicks out some pretty gutsy dyno results of 16.6 horsepower and 13.1 ft.-lbs. of torque. The Lightning exhaust system includes an 18" long, 5" x 8" straight-through, stainless steel MagnaFlow performance muffler and 3.5" polished stainless steel. Magnaflow exhaust systems have the highest exhaust flow rates and deliver the greatest quality of any Performance Exhaust System.