Overview: Once again, ladies and gentlemen, you asked and we delivered! The question was simple yet timeless: "Which makes more power, a dual 2.5-inch or a single 3.0-inch exhaust system?" To find out, we're swapping pipes on our run-of-the-mill 351 Ford, which makes about 400 hp, and to richen the pot we're also testing out turbo vs. straight-through mufflers and Y-pipe vs. a 90-degree merge. Come get all the data you can handle, right here on Engine Masters, presented by AMSOIL.