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Diesel and the Aftermarket

Upgrades increase acceptability

Given the building demand for diesel power, there's another side of the coin to consider. What sort of aftermarket upgrades can be added to improve performance, so an oil burner is more akin to the gasoline-powered vehicles we're used to driving?

Demands

A number of drivetrain mods are available that can make diesels more user-friendly. With companies like MagnaFlow Performance Exhausts forecasting a 25 percent growth in diesel products per year for the next five years, the aftermarket has been servicing the larger displacement diesels for a long time and is gearing up to meet the need for more mainstream products.

Parley Valora of Premium Performance, a diesel product wholesale/distributor in Idaho, compares the growth with another hot-selling segment. "The diesel market has grown at the same rate as the sport compact market," he says, "The OEs can't keep up with the demand."

Challenges

According to Keith Lockliear of Diesel Dynamics in Las Vegas, Nevada, the main challenge with smaller diesel upgrades will be the engine configuration. "We haven't had a chance to see the Liberty yet," he says, although they have an order in to DaimlerChrysler. "If it follows the pattern of the Dodge Cummins, the research and development shouldn't be a problem."

For instance, the turbocharger on the Ram diesel is mounted on the side of the engine block, offering plenty of space for aftermarket components. Another factor according to Lockliear is the Exhaust Gas Temperature (EGT).

Limits

"All the manufacturers determine their own safe limits of EGT," he says, "and all have some margin of safety." As an example, the 2000 Dodge Cummins is rated at 1,000 to 1,050 EGT at full boost, but can reach 1,250 safely. "We can add 80 to 100 horsepower with electronics and do it safely," Lockliear asserts. So, while there is still a lot of research and development as the smaller displacement diesels come onto the market, the aftermarket is poised and ready to meet the demand.

The diesel upgrades for the Jeep Liberty, Ford's V-6 Power Stroke (currently under development), and future small diesels, will undoubtedly follow the same pattern as the range of product for heavy-duty diesel pickups: electronics, exhausts with wide pipes, air intake and turbochargers. Space doesn't permit including all the diesel aftermarket products, but the following is a good sampling of what consumers might want to consider.

Products

Gale Banks Engineering offers the full spectrum of add-ons from its Six-Gun tuners to the Monster exhaust system as well as the PowerPack system with airflow, exhaust and turbo upgrades with properly matched fuel flow. The Six-Gun tuner and Speed-Loader add up to 155 horsepower and 385 lb.-ft. of torque on the big Duramax, with nearly similar gains for the Cummins and Power Stroke pick-ups. The Monster exhaust, with 4-inch pipes, cuts backpressure up to 92 percent, increases airflow up to 228 percent and lowers exhaust temperatures.

Hypertech's Power Programmer for diesels is more conservative with the powerband, opting for safe EGT limits. "We know the driver will scream the engine," explains marketing director Marla Moore. The diesel Programmer boosts power and torque, recalibrates the speedometer and odometer, and takes into account shift points and changes in wheel/tire packages. The tuner also allows the driver to keep the vehicle in the right gear on steep grades, a boon for both tow vehicles and rock crawlers.

Intercoolers, like those manufactured by Hypermax, are an alternative approach to both maintaining safe EGT levels and boosting performance and fuel economy in diesel engines. An intercooler, or air-to-air heat exchanger, is installed between the turbocharger compressor discharge and the intake manifold. Cooling the intake manifold air temperature lowers the exhaust temperatures; the cooler air temperature lowers the cylinder firing pressures, reducing the thermal and mechanical loads on the engine. The cooler, higher density air can increase power by 10 percent, fuel economy by around 5 percent and extend the already considerable life of the engine.

MagnaFlow Performance Exhaust upped the ante in diesel exhaust systems with 5-inch tubing available for the 5.9-liter Cummins high output engine. The company also markets a three-stage performance package including a MagnaFlow exhaust system and Performance Tuner plus a K&N Fuel Injection Performance Kit. This bundling of products is an ideal way for consumers to get the most bang for the buck.

Another form of diesel optimizer is Gear Vendors' Under/Overdrive. In effect, the pickup's manual transmission gear ratios are split, or divvied up into smaller, more efficient segments. As an example, the Dodge one-ton Cummins' sweet spot is around 1,600 to 1,700 rpm—that's where the trucks gets optimum engine efficiency. To hold onto a 70-mph highway speed up a grade, the rpm rises well above that optimum level. With a gear splitter, you can hold 70 mph up a hill and stay at a comfortably low cruising rpm.

Overall, it looks quite likely that diesel engines and related upgrades will be increasingly common in the mainstream market. We know they're coming, so keep your eye on those new diesel-powered vehicles coming down the road—they're the litmus test for the next big thing.