If diesel performance had to be condensed into a single photo, this would be it: a second-gen Cummins. Without a doubt, the ’94-’02 Dodge Rams fit with the 5.9L inline-six Cummins diesel set the tone for the high-horsepower oil-burners we have today. Big power potential was especially true for the ’94-’98 trucks, which in addition to being graced with the B-series Cummins, came with the coveted Bosch P7100 injection pump (a.k.a. P-pump). With access to the right parts and advice, big power is easy to achieve—and the truck can still be used to tow or haul anything you need it to.
It’s been two decades since the last Dodge Ram rolled off the assembly line packing 12-valve Cummins power, but thousands of enthusiasts are still willing to pump big money into them. Miles Flight is one such second-gen owner. In a textbook case of how to build a streetable P-pumped Cummins, his ’94 Ram 2500 sports compound turbos, a tweaked P7100 and a 24-year-old, completely untouched short block. Building his own suspension and steering components, a four-link system and five inches of lift was added up front, along with a dual steering stabilizer and third-gen tie rod assembly. The extra altitude paved the way for a set of 35-inch Nitto Trail Grapplers, mounted on 20x12 Fuel Mavericks, to be bolted in place in the wheelwells.
Follow along for a closer look at what makes this classic, 700hp diesel tick.
Original Yet Immaculate
Although time has never been good to the ’94-’02 Rams, the original paint on Miles Flight’s ’94 ¾-ton has held up extremely well over the years. Surviving 20-plus humid summers and salt-stricken winters is impressive enough, but the fact that this Ram served as a plow truck at one point in time makes it even more remarkable.
B.A. B-Series
While the 5.9L Cummins’ original bottom end has never been opened up, the cast-iron cylinder head was ported, polished and cut for O-rings by Enterprise Engine Performance. To stop valve float at high engine speed and valve creep under big boost and drive pressure, a set of 60 ppi valvesprings got the call as well. ARP studs secure the worked over 12-valve head to the undisturbed short block.
Well-Matched Compounds
A quick-spooling compound turbo arrangement entails a 64mm BorgWarner S300 (manifold/high-pressure charger) mounted over a 75mm S400 (atmosphere), both of which were sourced from Industrial Injection. Mounted to a PDI exhaust manifold, the internally wastegated S364 is responsible in getting things moving at low rpm. The S475 is non-wastegated, but makes use of a large, T6 mounting flange and moves a ton of air at higher rpm.
Mechanical Magic
Oftentimes glorified even more than the legendary Cummins B-series it’s bolted to, the P-pump is always at the forefront of any 12-valve’s horsepower-making recipe. And even though the unit employed on Miles’ Ram is the same 12mm, 175hp version it left the factory with, considerably more fuel has been coaxed from this particular P7100. Among the list of tweaks is a number 5 fuel plate, 022 delivery valves, billet rack plug and 4,000 rpm governor springs. Concluding the fueling mods is a set of 5x14 (Stage 4) injectors from Dynomite Diesel Products.
Supporting Mods
The job of keeping ample fuel supply on tap for the P-pump to use is left in the hands of an AirDog system. To guard against any low-on-fuel issues, diesel is pulled from the bottom of the factory tank via sump (shown). The AirDog system’s compact design bundles the water separator, fuel filter and lift pump together and mounts along the framerail. This particular 100 gph system sends 35 psi worth of fuel pressure toward the P-pump through a ½-inch diameter hose.
The Envy of All NV4500s
It’s not a ‘real truck’ without a manual transmission, right? Building on the NV4500 five-speed’s already-sterling reputation, Miles had Tantrum Drivetrain of Doylestown, Ohio build him a nearly indestructible unit, complete with a 1-3/8-inch diameter input shaft, stress relieved third gear and a chromoly main shaft. Engine-to-transmission power transfer begins with a 3600 dual disc clutch from South Bend. To date, it’s had no issues harnessing the truck’s dyno-proven 700hp and 1,500 lb-ft of torque.
Trail Grapplers on 20s
It’s no secret that big rims are the new norm in the diesel industry—and the 20-inch wheel craze hasn’t been lost on older truck owners, either. Thanks to a set of 20x12-inch Fuel Mavericks, Miles was able to blend a little new-age bling into the old-school Ram. With an aggressive stance and a quiet ride part of his hard-to-meet demands for a tire, Miles settled on one of the only tread patterns that somehow manages to accomplish both:Nitto Trail Grapplers. They measure 35x12.50R20.
The Back Forty
Although many believe the Dana 80 rear axle was only available on 3500 model second-gens, it was available on 2500s provided they were five-speed versions. For improved cosmetics, the 11.25-inch ring gear has been covered up by a polished aluminum diff cover from Spectre Performance. Two of the truck’s four Fox 2.0 Reservoir shocks can be seen here, too, along with the tail section of the 5-inch turbo-back exhaust system Miles had painted high-temp black.
All the Boost
A Phantom II series Auto Meter boost gauge is used to keep track of how hard the turbochargers are working. While the S364 over S475 arrangement doesn’t peg the 100 psi gauge, boost pressure does crest 70 psi under full load. Exhaust gas temperature and fuel pressure are also monitored along the driver side A-pillar.
Gauges
Some in-cab dressup comes in the form of white-faced gauge overlays in the OEM cluster. As far as the tach is concerned, don't mind that red line at 3,000 rpm. Thanks to all the fuel and air mods, that’s where the fun begins.
Old Dodge, New Tricks
While modern badging sometimes looks out of place on older vehicles, these late model 3500 series versions appear right at home on Miles’ second-gen.