Ford F-250 Power Stroke - Cheap Thrills

While it's obvious from the title of our magazine that we're all about performance, this term can mean different things. Sure, you can get a tuner to tweak that Power Stroke for blistering acceleration, but a diesel's strong suit is less about hauling ass and more about hauling stuff up a hill, whether it's a car trailer, boat trailer, or bales of hay.

Given that mission, what's the quickest and simplest way to increase the power output? By opening up the exhaust, of course. Not only that, a free-flowing exhaust system becomes the foundation for any further engine enhancements. After all, you can't shoot the flow of a fire hose through a drinking straw.

Removing the old exhaust system is sometimes the hardest part of the install, especially on an...	...older vehicle with rusty pipes. You can use WD-40, JB-80, or another lubricant to loosen bolts, but make sure the exhaust is cool	...before you start spraying. Then start removing parts by pulling out the stock muffler.
	The section with the catalytic converter comes out next.	You'll need to support the transmission and remove the frame crossmember to install the new downpipe.

To put it another way, think of that stock muffler as the weakest link in a chain. Your exhaust-and, thus, power-output is only as good as the smallest opening in the system. But the innards of a factory muffler typically consist of a maze of baffles and a small orifice that squeezes down to a smaller diameter. So even if the rest of the system has 3.5-inch tubing, the spent gasses still have to be forced through a little mouse hole.

Note the differences between the stock system (top parts in each picture) and the new exhaust system.		The Borla tubing is larger and has much smoother bends than the stock setup.
The optional short section (bottom) allows you to retain the factory catalytic converter, if necessary.
These close-ups of the stock tubing show the power-robbing pinches in the system. Using larger, mandrel-bent tubing, Borla eliminates these problems to encourage a higher output and lower EGT.	Bigger doesn't always mean better. Borla's Multi-Core XR1 muffler improves flow and tone too.	At the business end, it's obvious how much larger the Borla tubing is over stock.

In contrast, check out Borla's smooth, 4-inch, mandrel-bent tubing that flows nicely into the company's Multi-Core XR-1 muffler. This unit features a combination of freer-flowing perforated tubes along with insulation to cancel out noise, so the muffler's mellow sound is still within legal limits, with no annoying drone.