A while back, we did a one-day build of an ’02 Chevrolet 2500HD (“One Day Wonder,” August ’12) in which we modified the engine, transmission, and wheels and tires for maximum towing and daily driving capabilities. While the 364-rwhp Duramax was fast enough for the average person, the crew at Brown’s Diesel was nonplussed. “You should see what we can do with a Dodge!” they asserted. It was then that the idea of the big-power common-rail was born: a Ram truck built with bolt-on parts that would make huge power, yet still be reliable and driveable. Over the course of a few days, we followed along while a mostly stock ’06 Dodge Ram 2500 was transformed into a fire-breathing monster.
| big Power Common Rail Part 1 dodge Ram Side Shot
Part one of this two-part series involved prepping the truck for more than twice the power it currently had, and with each step, we’ll tell you why each modification was performed and how it benefited the build. In part two, we’ll cover the performance modifications that were made in order to extract another (hopefully) 200-plus hp out of the already potent 5.9L Cummins engine. Unspoken power expectations were 600 rwhp with a small single turbo and 800 with nitrous—so we knew a stout foundation would be needed. Without further ado, we’ll delve right into what it takes to make a reliable street truck at power levels approaching quadruple digits.
Day One Total Cost: $9,515
When we added everything up, it was quite a bit cheaper than we thought, considering this is the level of prep you’d see on a Diesel Power Challenge truck. We actually snuck in under the 10-grand mark, at $9,515. Of course, your cost may vary. For a truck with head studs, a built transmission, and all the air and fuel supporting modifications for big power, the price isn’t all that bad. This setup is very reliable, too. We’ve seen third-generation Dodges with similar modifications last for years at 700 to 900 rwhp without any major failures.
What it is: Rebuilt transmission with Goerend valvebody and Alto clutches ($1,750)
| big Power Common Rail Part 1 rebuilding A Transmission
Why you need it: While the 48RE transmission found in ’03 to ’07 Dodge Rams is stout in stock form, the tremendous torque added when a diesel engine is modified makes the transmission one of the first weak links. A performance valvebody from Goerend Transmission Inc. was installed to increase line pressure and firm up shifts, while a set of performance clutches will provide more aggressive friction material to make sure the rest of the transmission can keep up with the valvebody.
What it is: Goerend triple-disc torque converter ($1,200)
| big Power Common Rail Part 1 torque Converter
Why you need it: The stock single-disc torque converter is fine for factory power levels, but unfortunately it won’t hold up to big horsepower. A higher-stall-speed Goerend converter was used to provide better spooling once a larger turbocharger is installed. And when the lockup switch is hit, a three-disc converter clutch will engage and provide much more clamping force than a single disc.
What it is: Sonnax 300M input shaft, TCS 300M output and intermediate shafts, and Sun Coast billet flexplate ($2,400)
| big Power Common Rail Part 1 suncoast Flexplate And Input And Intermediate Shafts
Why you need it: Most daily-use vehicles can get away with just a billet input shaft and flexplate to handle added transmission stresses, but since this truck will be drag raced, sand dragged, and sled pulled, the transmission received 300M intermediate and output shafts as well. The shock loads from these performance activities are tremendous and can snap stock shafts like twigs, or rip out the center of factory flexplates. These parts are available from most major diesel transmission companies.
What it is: Raptor 100 lift pump ($395)
| big Power Common Rail Part 1 raptor 100 Lift Pump
Why you need it: If the factory in-tank lift pump can’t keep up, rail pressure from the CP3 injection pump will drop, and so will horsepower. We’re not talking about peanuts, either; low rail pressure can cost 50 hp or more. A Raptor 100 was installed on the Dodge to prevent this scenario from happening.
"Virtually every aspect of this trucks drivetrain was upgraded to handle extreme power and the rigors of competition."
What it is: ARP head studs ($1,200)
| big Power Common Rail Part 1 arp Head Studs On Cummins Engine
Why you need it: Since the eventual goal of this truck was to top 800 rwhp, high-end ARP 625 head studs were employed in place of the factory head bolts. The greater clamping force from the ARP studs means the engine can handle much more cylinder pressure and boost without blowing a head gasket. If the truck is low-mileage, these studs can be threaded in and torqued down one at a time from the center of the head out, without ever removing the stock cylinder head and gasket.
What it is: EFILive tuning ($650)
| big Power Common Rail Part 1 efi Live Tuner
Why you need it: Perhaps the most important aspect of all is a tune that matches the truck’s modifications. And with EFILive software fuel tables, injection timing, injector pulse width, and transmission tuning can all be tailored to the needs of the vehicle. While the Ram already had a 360-rwhp tune courtesy of Brown’s Diesel, a much more serious tune can later be built with the same software when further upgrades are completed.
What it is: Performance gauges ($300)
| big Power Common Rail Part 1 boost Gauge
Why you need it: Gauges are a very important part of monitoring a truck’s progress and performance to make sure rail pressure is up, the turbo is not overboosting, and the transmission is at a livable temperature. For this build, boost, exhaust gas temperature, and rail pressure gauges were used.
What it is: Aftermarket exhaust ($700)
| big Power Common Rail Part 1 exhaust Stacks On Dodge Ram
Why you need it: Stock exhaust is fine for a stock turbo, which maybe needs to exit about 20 psi of air. However, once the engine can produce 40 or 50 psi of boost, the exhaust must be upgraded to something like the 5-inch Grand Rock stacks seen here. If you’re going the stacks route and are going to be heading on any long trips, it’s recommended that you leave your catalytic converter and/or muffler on—or the resonance in the cab will be very loud.
What it is: Intake horn ($285)
| big Power Common Rail Part 1 afe Intake
Why you need it: In addition to having some more area for flow, this AFE intake horn also has ports for monitoring boost, water injection, nitrous, or whatever else someone would want to install on an engine. For this Cummins, these bungs will be used for multiple stages of nitrous.
What it is: Intercooler boots ($240)
| big Power Common Rail Part 1 intercooler Boot
Why you need it: The intercooler boots on third-generation Dodges are pretty good. However, this truck received an upgrade to thicker boots as a precaution. When running on the ragged edge of a turbo, a blown or torn intercooler boot can mean the turbo will overspeed and come apart. For a few hundred bucks, this kit provides cheap insurance.
What it is: Air intake ($395)
| big Power Common Rail Part 1 air Intake
Why you need it: Making horsepower all starts with air entering the engine, which means a good air intake is a necessary step as power increases. Especially when the turbocharger is upgraded, a good-flowing intake can be worth some horsepower and makes life easier on the turbocharger. Toward this end, an AFE intake was installed on the truck for maximum flow.
