The holy grail for many hunters and fishermen isn’t an in- your-face largemouth that straightens a 2/0 hook or a big whitetail that makes the book. It’s a 4×4 with more power. Guys who push a four-wheel-drive pickup or sport utility to the limit by climbing high-mountain offroad trails or horsing a boat and trailer off a steep, muddy boat ramp have learned that modem 4×4s all too often come up a bit short in the power department.
But extra power sometimes comes at a hefty price.A turkey-hunting buddy put it to me point blank: “I want more power, but I don’t have the budget or the time for a complete engine overhaul or really expensive accessories.What can I do?”
As it turns out, plenty.
By focusing on the exhaust side of the engine, you can give a 4×4 much more seat-of-the-pants performance at a price you can bear. The reason exhaust modifications can pay off so handsomely is because engine performance boils down to combustion efficiency. For an internal combustion engine to make power, it must efficiently convert fuel into heat (power). How well it does this is a measure of its combustion efficiency. Combustion residuals (exhaust gas) that are allowed to remain in the cylinders after each combustion process reduce efficiency, which translates into a loss of power. But if you can rid the engine of exhaust gas faster, you can increase the efficiency of the engine—and that means more power, better fuel economy, and improved driveability. Longer engine life can also result. All in all, pretty good benefits.