When the ’08 Ford Super Duty debuted with common-rail injection and compound turbochargers under the hood, it was a true gift from the manufacturer. A short while after its release, it wasn’t uncommon to hear about trucks making 550 hp at the wheels with just an air intake, free-flowing exhaust, and a hot tune. No doubt, the 6.4L Power Stroke’s compound-turbo arrangement made this possible. But for the folks who like to tow in conjunction with running a peppy tune, the stock chargers don’t always cut it. Exhaust gas temperature can exceed 1,600 degrees, and the EGT problem is only magnified at elevation.
| Elite Diesel Engineering’s new High-Power compounds were designed to keep a modified 6.4L Power Stroke’s exhaust gas temperature in check while towing. The challenge was to create a larger compound-turbo arrangement without sacrificing spool-up and causing turbo surge. To see if it had accomplished that goal, we flew out to Colorado to watch Elite test its new turbo system at elevation, and with a trailer in tow.
Elite Diesel Engineering of Pueblo West, Colorado, set out to solve this EGT debacle and provide a bump in horsepower at the same time. Beginning with an ’08 Ford F-250 equipped with custom tuning and stock BorgWarner turbochargers, it ran several tests towing a 10,000-pound trailer at 5,800 feet above sea level. Then, Elite’s larger turbos were installed, and the same test was repeated. The results? How about a 200-degree reduction in EGT, stock-like spooling characteristics to get the load moving, and a 50hp gain? Follow along as we show you the install, tow test results, and the truck’s new power curve.
’08 F-250 Super Duty Test Mule Specs:
Air intake: S&B system, 6.0L CFM Plus elbow with Elite Diesel adapter plate
Intercooler: Spearco
Exhaust: MBRP 5-inch DPF delete, 6.0L exhaust manifolds, Elite Diesel up-pipes, EGR delete
Wastegate: External unit from Precision Turbo and Engine
Fuel System: AirDog II 165-gph
Tow Tune: Innovative Diesel Performance’s Extreme Street file (285hp tune)
Transmission: Elite Diesel TorqShift
*The only change made to the truck was the turbo swap performed between tests
*Elite’s High-Power compounds retail for $7,175
Tow Test Parameters
Tow route: I-25 near Colorado City (elevation approximately 5,800 feet)
6 percent grade
50 degree ambient air temp
10,000-pound trailer
51-to-72-mph acceleration
Tow Test, Before and After:
Remember Project Godzilla? If you do, this truck should look familiar. Now re-equipped with stock injectors, the factory Siemens injection pump, and (prior to this story) stock compound turbos, the truck’s only means of added horsepower was custom tuning from Innovative Diesel Performance.
| 6 4l Pwer Stroke Turbo Upgrade super Duty Towing
The test location was near Colorado City, Colorado, along Interstate 25 and was performed on an uphill grade at an elevation of 5,800 feet. Elite’s test trailer (2,500 pounds) was loaded with a 1-ton, 6.0L Power Stroke-powered van (7,000 pounds) and 500 pounds of tractor weights for a curb weight of exactly 10,000 pounds.
Thanks to the retention of the variable-geometry exhaust housing on the high-pressure turbo, the ball-bearing center cartridge in the low-pressure turbo, and the addition of the billet-aluminum compressor wheels in both turbos, spool-up wasn’t compromised at all while running a performance tune. Empty or loaded, the truck had factory-like responsiveness and pulled a lot stronger than with the stock compound arrangement feeding the engine.
Stock Compound Turbo Test
51-to-72-mph acceleration: 16.00 seconds
Maximum EGT: 1,600 degrees
Average boost: 38 psi
Elite Diesel Engineering High-Power Compound Test
51-to-72-mph acceleration: 14.00 seconds
Maximum EGT: 1,400 degrees
Average boost: 45 psi
