MAY ALREADY BE SITTING IN YOUR DRIVEWAY
In the pursuit of piecing together the perfect daily driver, many of us allow the end goal to control the course of the build. We get so caught up in the final horsepower number that we neglect to realize how well the truck performs after incremental yet completely necessary mods have been made. Not so for Jake Bosie and his ’12 Ram 2500. In the midst of making the necessary foundational upgrades that would help his fourth-gen support 700-750 hp, he took stock of the setup he’d already come up with: a dyno -proven 576hp, 1,166 lb-ft everyday driver. Though not perfect, so far it’s gotten him to work, towed anything he’s asked it to, and even played on the street. Most impressive, over the course of the past three years the factory 68RFE hasn’t skipped a beat.
100-PERCENT STOCK CUMMINS—FOR NOW
To date, the 112,000-mile 6.7L Cummins hasn’t been touched other than a quick running o f the valves. And even though Jake knows the four-digit torque number the truck is making and the 40 -plus psi of boost he’s cramming into the engine could eventually yield a blown head gasket, he doesn’t lose sleep at night over it. Should the head gasket go while he’s still rounding up the funds and parts that will complete his 750hp recipe, the head will be pulled, cut for fire-rings, and cinched back down with ARP studs.
SECOND-GEN TURBO SWAP
Starting with a larger turbo rather than an injector and CP3 upgrade, Jake ditched the factory Holset HE351VE variable geometry charger for a unit that offered more flow and improved reliability. This meant a fixed geometry unit in the form of a BorgWarner S400 was on the table. To make it happen, Jake installed Fleece Performance Engineering’s second-gen hardware kit and sourced an S467 through Fleece as well. The BorgWarner uses an 83mm turbine wheel, a spool-friendly .90 A/R exhaust housing, and mounts courtesy of a T4 divided flange Steed Speed exhaust manifold.
ELECTRONIC EXHAUST BRAKE
Because Jake tows heavily on occasion and hauls an in-bed camper all summer, stopping power is important. Thankfully, he was one of the first customers in line to receive Fleece Performance Engineering’s innovative new exhaust brake. The electronically actuated exhaust brake works in conjunction with a fixed geometry turbocharger, is plug-and-play as far as wiring is concerned, and performs as effectively as the factory brake did. Thanks to this addition, Jake can take advantage of the extra 60 to 70 horsepower and cooler EGT the S467 provides while still being able to bring everything to a halt as quickly as he could when the truck was stock.
STOCK FUEL & GOOD TUNING
From the outset of adding the Fleece second-gen turbo kit and S400, Jake had plans to “just deal with” the truck’s pending turbo lag until the bigger injectors and stroker CP3 went in. What he didn’t count on was Motor Ops knocking the tuning out of the park on the first try. Having spent time behind the wheel ourselves, we can honestly say the S467 spools extremely well, even on stock fuel. When running the hottest file in the truck ’s arsenal, the S400’s responsiveness is nearly comparable to the stock VGT. Exhaust gas temps are better, too, with the S467 cooling peak EGT down by more than 200 degrees. Jake’s one fuel-related mod included the installation of Fleece’s Powerflo in-tank lift pump, which with its ability to support 800hp was added to aid his future horsepower goal.
68RFE SECRET SAUCE: TCM TUNING
Believe it or not, Jake’s Cummins has been sending just shy of 600 hp and 1,200 lb-ft through the stock 68RFE for a couple of years now. His secret? Allowing the minds at Motor Ops to infiltrate the transmission control module to optimize its shift points, improve converter lockup, and ramp up line pressure. To be sure, a built ’68 is on Jake’s list of things to do, but for now the combination of good tuning and driving sensibly (no boos ted, four-wheel drive launches) has kept the factory automatic in perfect working order.
THE NEXT STEP(S)
Though Jake still intends to press forward with his 700-750hp build, the present parts combination has made his ’12 very fun to drive. It spools quick , runs exceptionally clean, and makes respectable power. The next step, building the 68RFE , will be his largest expense—but it’s one that will afford him the ability to enjoy the additional 150hp he plans to make with the truck for years to come. Once a rock-solid six-speed is in place, it’ll be time to fire-ring the head and add head studs. After those insurance items are in place, Jake will throw a set of 60-percent injectors and a stroker CP3 at the engine, along with a tuning revision. If you’re looking for the perfect blueprint for power for your 6.7L Cummins project, this is the way to execute it.