Easy bolt-ons can give 7.3L...
Easy bolt-ons can give 7.3L Power Strokes nearly 50 percent more towing power.
Diesels are hot. They simply out-torque, out-tow, out-mpg, outlast, and pound-for-pound, outperform anything on the planet. These vehicles can produce 300 hp and 560 lb-ft at the rear wheels and still get 20 mpg on the highway - in spite of a hefty 8,500-pound GVW and the aerodynamics of a barn door, in the case of our 2002 Excursion 4x4.
Diesel technology has come a long way. With the increasing demand for diesel power (70 percent of all new Super Dutys are diesel-equipped), truck makers are aggressively pushing diesel development. Diesels' impressive torque numbers and fuel efficiency can be explained with a few simple facts: Diesel fuel has a higher energy content (BTU) than gasoline by approximately 10 percent, and diesel engines operate at much higher compression ratios (20:1 and up) than gas engines to exert a greater mechanical advantage on the crankshaft at lower rpm. Modern diesel engines are turbocharged with extremely high boost pressures and resist detonation better than gas engines. These factors add up to incredible torque and high fuel efficiency - just what a truck owner needs to tow his trail rig, travel trailer, or boat (or even rip past that Mustang GT).
Late-model diesels can be easily modified for substantially more performance. With a few DIY bolt-ons, we added 100 hp and 160 lb-ft of torque without negatively affecting fuel economy - try that with your gas engine!
We obtained this sizeable increase with a handheld Evolution Programmer from Edge Products, a K&N Fuel Injection Performance Kit (FIPK) intake system, and a 4-inch-diameter Magnaflow Downpipe-Back Exhaust System. All these modifications can be accomplished at home in less time than it takes to watch a 500-mile NASCAR race.
Most performance chip and programmer manufacturers recommend a less restrictive intake and exhaust systems to keep exhaust gas temperatures (EGT) in check. Our experience with turbocharged gas engines had also shown big gains in turbo response with better breathing, and diesels should be no different.
Performance-Parts Trifecta
First, we installed a K&N FIPK (PN 57-2430). It replaces the factory airbox and restrictive paper element filter with a low-restriction K&N cotton gauze/wire mesh air filter, a high-flow polyurethane intake tube, and a metal heatshield that isolates incoming air from hot underhood heat. The installation took less than a half hour.
Diesel engines need frequent air filter replacement to deliver peak performance. K&N air filters can be cleaned and re-oiled with K&N's Recharger Kit - plus, every K&N air filter carries a million-mile warranty. When you're dealing with an engine that can go 350,000 miles between rebuilds, a million-mile air filter makes a lot of sense.
 1. The first thing to go...  1. The first thing to go was the restrictive OE airbox and filter. Unsnap the airbox lid and loosen the hose clamps that attach the intake hose to the manifold. |  2. Next, the stock paper...  2. Next, the stock paper air cleaner element is removed for access to the four bolts that secure the airbox. Then the air-temperature sensor on the side of the box is slipped out of its grommet. |  3. The bolts that hold the...  3. The bolts that hold the airbox in place are removed and will be reused. The airbox is slipped out of the fresh-air intake duct and removed from the vehicle. |
 4. The kit's heatshield is...  4. The kit's heatshield is prepped by attaching the intake tube support bracket and rubber insulation strip. Then it's bolted into place and the air-temp sensor is pushed into place in the shield. |  5. K&N tech Kirk Swanson...  5. K&N tech Kirk Swanson slid the silicone coupler over the composite intake tube, then attached it to the intake manifold. |  6. Next, the OE restriction...  6. Next, the OE restriction gauge is fitted to the end of the K&N Filtercharger. The filter attaches to the intake tube with a stainless-steel clamp and to the fenderwell with a support bracket. |
Next, we got a Magnaflow 4-inch-diameter stainless-steel exhaust system (PN 15930) to replace the restrictive OE exhaust. It comes in three pieces: a front piece, a 24-inch-long straight-though absorption-type muffler, and a tailpipe with a highly polished 5-inch-diameter exhaust tip.
The muffler, which is 7 inches in diameter, is also highly polished. The system bolts up directly to the stock downpipe and has factory-style barbed hangers that slip right into the factory isolators. The quality of the high-flowing mandrel bends and the perfect fit really impressed us, as did the system's lifetime warranty. The Magnaflow exhaust could easily be installed in less than an hour. (Magnaflow also offers turbo-back systems, which are even freer-flowing but take longer to install.)
 7. If you don't want to cut...  7. If you don't want to cut the factory 3.5-inch exhaust system with a Sawzall, take off the rear shock to remove the muffler and tailpipe as a unit. |  8. Magnaflow's 4-inch-diameter...  8. Magnaflow's 4-inch-diameter stainless-steel system features mandrel bends, a polished 7-inch-diameter muffler, and OE-style hangers. This downpipe-back system bolts up in a matter of minutes. |  9. The 5-inch-diameter polished...  9. The 5-inch-diameter polished tip is actually double-wall thickness to prevent heat from discoloring outer layer. It lets everyone know that this Power Stroke means business. |
In the world of modern electronics, Edge Products has forged a solid reputation for its Juice plug-in diesel control modules and Attitude multifunction engine monitor/ controller. The company's Evolution Programmer removes the stock engine-management software, then installs one of three performance curves:
Tow: 60 extra hp/100 lb-ft of torque with minimal exhaust gas temperature (EGT) increases
Race: 80 hp/160 lb-ft for additional non-towing performance
Extreme: 100 hp/250 lb-ft of non-California-emission-compliant power