Blazing a Different Trail: Upgrading a Nissan Titan XD Cummins
The Nissan Titan XD diesel is a neat concept, but since its inception, many traditional North American truck buyers have used every excuse under the sun to avoid them. It’s not a Ford, Ram or Chevy, so it’ll never catch on. It’s not quite a ¾-ton, not quite a half-ton and no one wants a 5/8-scale truck. The Cummins option is cool but it isn’t an inline-six, so you might as well just stick with a Ram 2500. Makes sense, right? Josh Chapman doesn’t think so. Since getting his hands on one a few years ago he now operates CFT Performance, a business that specializes in Titan XD diesel performance and consumes most of his waking hours.
But why is Chapman so busy? As it turns out, in the rarely-exposed world of Titan XD performance, the 5.0L Cummins V8 is a powerhouse with loads of untapped potential. After performing what most automotive enthusiasts would consider to be mild modifications (namely tuning and a turbo upgrade), Chapman’s ’16 model sends just under 550rwhp to the pavement. To our knowledge, this makes it the most powerful Nissan Titan XD Cummins in the world. The best part? Doubling the factory horsepower rating did nothing to hinder its street manners or drivability—and Chapman still hooks it to his 12,000-pound camper on the weekends. We recently caught up with Chapman for a glimpse inside his record-setting Titan XD. This is his story.
CGI Block, Aluminum Heads and DOHC
While the 5.0L Cummins V8 under the hood of Chapman’s ’16 Nissan doesn’t look like this anymore, it’s important to know what he was working with from the factory. Assembled at Cummins’ Columbus, Indiana engine plant, the 90-degree V8 utilizes a compacted graphite iron crankcase, aluminum heads with four valves per cylinder, dual overhead cams and composite valve covers. Last but not least, a Holset M2 two-stage turbo system made for instant torque and squeaky clean emissions in stock form. Rated at 310hp and 555 lb-ft at the flywheel but known to belt out 280rwhp on chassis dynamometers, these engines were either underrated from the factory or the A466ND Aisin transmission is just that good.
Slightly Modified
Immediately, you can see that things are a bit different on Chapman’s 5.0L Cummins. In addition to the CCV XD catch can, a pre-cool coolant hose kit powder coated by Kcin Coating and Chapman's own fabricated coolant overflow tank, much of the CFT Performance big single turbo kit is visible. Designed to do away with the restrictive factory two-stage turbo system, Chapman’s single turbo kit accommodates a fixed geometry BorgWarner S300 via a T4 divided pedestal made from 304 stainless (complete with an integrated oil drain). The system also includes a 4-inch diameter 304 stainless steel downpipe, custom cold air intake with filter and all required hardware. So far, Chapman sees a 1:1 drive-to-boost pressure ratio most of the time, whereas a 2:1 ratio was common with the factory turbos still in the mix (in addition to being rough on turbochargers, excessive drive pressure is known to be hard on engine parts).
Joining the Five-Blade Mafia
This is the turbocharger responsible for helping Chapman’s Titan pick up more than 100hp at the wheels: a five-blade S366 from Stainless Diesel. Tucked in beneath the factory intake manifold, the BorgWarner-based charger features Stainless Diesel’s five-blade billet compressor wheel (which is known to support as much as 800rwhp in other applications), a T4 divided (and non-wastegated) turbine housing with a .91 A/R, a 74/80mm turbine wheel and a 90-degree compressor outlet. At full song, the five-blade S366 builds as much as 60 psi of boost.
Keeping Things Cool
Helping to drop coolant temps, Chapman fabricates his own coolant overflow tanks in-house as well. It’s made from 1/8-inch thick, 6061 T6 aluminum and uses all factory hook-ups. The tank, which bolts directly into the stock location, also features a Pyrex sight tube and comes with a lifetime warranty. It can be powder coated a host of different colors, but Chapman prefers what he calls “CFT Performance Green.”
Mostly Stock Fuel System
At the front of the lifter valley, you’ll find a Bosch CP4.2 high-pressure fuel pump aboard all Titan XD Cummins engines. In the Nissan application, this pump benefits from a chassis-mounted electric lift pump sending more than 75 psi of fuel pressure its way. The CP4.2 then pressurizes diesel as high as 30,000 psi before sending it to the rail and ultimately to eight piezoelectric injectors. During his record-setting dyno session at Stainless Diesel, Chapman’s 51,000-mile CP4.2 had no problem maintaining 28,000 psi of rail, but lift pump pressure did dip to 62 psi. Chapman has since installed a 125 gph FASS system in place of the factory lift pump, which will be able to maintain 75 to 80 psi—even with larger injectors in the equation.
548RWHP, 930 LB-FT
Driving the truck 350 miles (each way) up to Stainless Diesel’s Middlebury, Indiana location, Chapman’s Nissan managed 19.5 mpg, but this was no fuel economy run. Once the Titan was strapped to the company’s chassis dyno, a Dynotech unit with dual eddy brakes, it was time to face the music. After making a few test hits on lower horsepower tunes that yielded between 396rwhp and 446rwhp, the shift-on-the-fly switch was turned up and an incredible 548rwhp was the result. Peak torque checked in at 930 lb-ft.
Expectations Exceeded
This is what it looks like the moment your goal of (hopefully) making 500rwhp on the dyno turns into nearly 550rwhp. Even Stainless Diesel owner and dyno operator, Johhny Gilbert, a man with a 2,400hp Pro Street truck at his disposal, seemed impressed with the mighty Titan’s numbers. As you might’ve imagined, before the rollers even stopped spinning, the gears inside Chapman’s head were already turning. As we write this, he’s piecing together a plan to breach the 600rwhp mark.
Backing Up the Numbers
To back up the 548hp pull, the truck was run again. The result? 546rwhp and a similar torque figure. With 50 psi registered on the boost gauge (thanks to Chapman’s installment of a 10 bar MAP sensor) and 60 psi possible on the street, there might’ve been a little more left in the turbo. However, with lift pump supply pressure dropping and a 350-mile hike back home still ahead of him, Chapman decided to call it a day with his 548 and 546rwhp numbers.
Dyno Test Complete, Headed for the Drag Strip
Constantly fine-tuning engine calibrations and evaluating their performance, Chapman works with several tuners, including Kory Willis of PPEI and CTT. CTT’s mastery of EZ Lynk tuning is accredited to yielding the 548hp number you see here. Next up, Chapman plans to get the world’s most powerful Titan XD Cummins down the dragstrip. He’s hoping for low 13’s or high 12’s. We’re hoping he sees the latter.
Photos courtesy of Amy Gilbert of Stainless Diesel and CFT Performance.
