Once you begin a project truck, especially an older one like a 1996 Ram, the list of mods and upgrades can go on and on. In looking back at all the changes made on it over the years, it almost came as a surprise just how much can be done to a dependable diesel. But that really shouldn’t be unexpected on a 12V Cummins, considering that they run seemingly forever, so the effective duty cycle can be measured in decades.
In our first installment, we provided a broad overview of the exterior mods and cosmetic improvements done to this aging Dodge. In this second part, we’ll go into a bit more detail on some mechanical upgrades such as the turbo and fuel systems.
Since they took place over a span of several years, we’ll be jumping around a bit, but you can pick and choose whichever items might interest you and suit your particular needs. In some cases, they have a different application than just on a 1996 Dodge with a 12V Cummins. Stay tuned, because there’s more on the way, as this hard-working rig is about to complete its second decade on the road.
ENGINE OF DESIRE
When we purchased this 1996 Dodge about a decade or so ago, it had only 110,000 miles on the odometer. In diesel miles, that’s just getting broken in. The previous owner had already made a number of changes, such as installing a K&N air filter, #8 fuel plate, electric fan, remote fuel filter, ATS transmission, and Gear Vendors gear splitter, among others. Clearly he enjoyed spiffing up his pickup. When we told our mechanic about all the aftermarket upgrades on it, he joked, “Hey, you only paid for those aftermarket parts—and got the truck for free!”
Even so, we couldn’t resist messing with it, so we added an ATS high-flow exhaust manifold and performance turbo. But perhaps not the type of performance you might expect. Rather bombing down a drag strip, this Cummins-powered Dodge is primarily a work truck used for towing a travel trailer and boats, and hauling boat docks over fairly long distances. So while more horsepower is welcome, extra torque is the main thing for this particular application. High horsepower levels are more for sport and competition applications.
In order to improve the power band without going overboard, we started with the exhaust manifold. As much as we like the 5.9-liter Cummins powerplant, the stock exhaust manifold is constrictive and contorted, interfering with the flow of gases to the turbo and downpipe. That in turn can produce a cherry-red condition. As a result, certain sections are prone to heat-induced cracks, which can make your steeds pull up lame.
For a less obstructed flow, which lowers EGT and improves throttle response, ATS developed a three-piece unit called the PulseFlow. Available for 12- and 24-valve Cummins engines, and common-rail versions as well, it’s designed to let the turbo spool up sooner with less exhaust backpressure and increased fuel efficiency. This pulse manifold design also eliminates the problems with shrinking and breaking, as well as cracking and gasket issues. The separate sections, joined together by ball/socket joints, are not only smoother in shape, but also allow for expansion and contraction to prevent fracturing. A high-temp coating helps keep the surface temperature down as well.
Installing the ATS unit took about a half-day, and we noticed two immediate benefits. The EGT was as much 100 degrees cooler (depending on load factors, and when used in conjunction with a Banks exhaust system). Also, the throttle response became noticeably quicker, with less foot pressure required to accelerate and maintain a given speed.
Next we added an ATS Aurora 2000 turbo (now offered as the 3000 model instead). This company makes several levels of turbochargers, and as much as we like the idea of a super-spinning pinwheel on a diesel, we’ve got a job to do, so we opted for somewhat more modest gains, in favor of towing power over hauling ass. The ATS Aurora 2000 (and 3000) turbo is designed for a quicker response, and improved low-end and midrange torque, while reducing EGT and maintaining good fuel economy.
The numbers prove this out. ATS data charts indicate the Aurora’s airflow is 877 cfm, versus 555 cfm for the Holset, roughly a third more.
The output of the factory turbo is 295 hp at the flywheel, while the Aurora can produce as much as 466 hp (depending on other modifications to the injectors, intake and exhaust, all of which had already been modified on this particular truck). And the newer 3000 Aurora can support as high as 500 rwhp, ATS notes.
Spool time is also reduced with the Aurora, dropping from 6.1 to 3.7 seconds. Interestingly enough, even though the airflow and power output numbers are much higher, the increase in max boost is not that much greater, 35 psi stock to 40 psi for the Aurora.
That’s because the Aurora works smarter, not harder, by increasing the efficiency of the compressor. Without getting overly technical about the internal design of the compressor wheel, it features several improvements in the blade shape and angle, along with the diameter and housing.
Another significant difference in the Aurora line of turbos is what it doesn’t have: a wastegate. Typically this feature is used to relieve backpressure, and also allows for a smaller turbine housing. How did ATS dispense with this item?
ATS explains that turbine wheel and housing are matched to the volumetrics of the engine, so they absorb all the energy of the gas for more efficiency. With less restriction in the turbine housing, no wastegate is needed, so there’s more flow and less boost pressure. This configuration, however, requires meticulous matching of the turbine and compressor, and a different type of internal design. The shaft that connects the turbine with the compressor wheel is free-floating, with the bearings spinning on a film of oil.
While the internals of the Aurora are substantially different, replacing the factory unit is a simple swap. Installation of the ATS unit went quickly in just a couple hours. And both the manifold and turbo proved their worth over many years of hard use.
But all good things come to an end, so a few years and many miles later we added a Banks PowerPack and water meth, taking advantage of some recent advances in performance technology and a wider choice of new upgrades.
The Banks package consists of a Ram-Air cold-air intake, a Twin-Ram intake manifold, a somewhat larger prototype of the Sidewinder Turbo with a big-head wastegate actuator, and a Monster Exhaust. The gains over stock output were significant: 94.4 hp at 2,200 rpm, hitting a peak of 249 hp. As for torque, the dyno recorded an increase of 227.6 lb-ft at 2,000 rpm, topping out at 608.4 lb-ft. Those numbers amount to a 60 percent or more increase in output over stock, both in horsepower and torque.
The results on the street were significant. The 0-60 mph time, when unloaded, dropped from the factory time of 12.75 to 9.69 seconds, more than three seconds quicker for a 24 percent improvement. When towing, the 0-60 mph time dropped 34 percent, from 39.67 to 26.01 seconds.
Adding the Banks Straight Shot water/meth system on top of the PowerPack produced even bigger gains across the board. Peak output recorded on the dyno was 305.2 hp (more than 105 hp, or 97 percent), and 745.8 lb-ft (a gain in excess of 365 lb-ft, or 92 percent). Clearly these additional upgrades made a dramatic difference in performance.
INCREASING FUEL CAPACITY WITH AN AERO UNDERBODY TANK
The reasons for adding extra fuel capacity are numerous, even though we’re seeing lower prices at the pump of late. Having a larger tank not only provides the extended range, it also lets makes it easier shop around for the best prices on fuel. And having more of a reserve on tap is a good thing when towing increases your rate of fuel consumption.
While you can add an auxiliary tank in the pickup bed, the advantage of an underbody unit is that it doesn’t take up any space in the cargo area. The in-bed tank may also require extra plumbing and valves for switching between two tanks.
Aero makes replacement tanks for every domestic make of truck, and also tanks for toy haulers, RVs, and all sorts of custom applications. Instead of using plastic, Aero fabricates its underbody tanks from enamel-coated, aluminized steel with internal baffles, a drain plug and through-bolted steel mounting tabs.
While do-it-yourselfers can do a tank swap if they have the right tools, most of Aero’s customers have the installation done at the factory. And for good reason, because the warranty on a factory job is slightly better, three years/50,000 miles, versus two years/30,000 miles on a DIY install.
Our particular application on a 1996 Dodge Ram required some custom work, in order to clear the mounting plate for a Gear Vendors gear-splitter. For a modest extra charge, Aero can custom-weld a tank with a recessed area to make room. Even with this modification, the tank capacity went from 36 gallons for the stock unit to nearly 60 gallons in the underbody tank.
There’s another point to consider when changing out the tank. The sending unit on the fuel pickup assembly on older Dodges can wear out as soon as 40,000 miles or so, and that was the case on this aging truck. Note, however, that Aero points out one difference in the gauge readout after upgrading to a larger tank. Since the factory pickup is retained on the larger tank, the fuel needle will stay on full for the first 15 to 20 gallons. It’s not really an issue, but simply an expected aspect of this upgrade. DW