The 3.5L EcoBoost V6 engine in the Ford F-150 is a stalwart piece. Since its introduction in 2011, it’s been proven to perform like a V8 engine with the economy of a six-cylinder. The dual overhead camshaft EcoBoost V6 in this application is rated at 365 hp and 420 ft-lbs of torque, far eclipsing the older F-150’s three-valve V8’s performance.
It achieves this through the use of a pair of Borg-Warner K03 turbochargers designed to produce 12 psi of boost, along with the use of direct-injection technology to improve emissions and throttle response, while providing the increased output required to haul the F-150’s heft around. The F-150, when equipped with this engine, has a maximum tow rating of 11,300 pounds yet delivers more fuel efficiency when compared to a traditional V8 engine.
The boost is routed through a traditional air-to-air charge air cooler and into the engine, and this is where a new upgrade from Vortech Superchargers comes in. Vortech’s Charge Air Cooler for EcoBoost F-150s, part number 8N310-010, is designed to vastly reduce power losses that these trucks experience as inlet temperatures rise by keeping heat soak at bay.
Background And Construction
The concept of charge air cooling a turbocharged application is not new – it’s been the industry standard for many years to reduce inlet air temperatures to keep the incoming air cool. The hotter the air charge temperature is, the more ignition timing must be pulled from the engine calibration to compensate and prevent preignition (detonation). As turbochargers heat the exhaust flow (that’s already hot on its own) the inlet air’s density also decreases due to both the heat generated by compressing the air and heat transferred from the exhaust to the intake air charge. These increased temperatures subsequently also hurt power.
Charge air cooling works to reverse the heating trend and return the density to the air ingested by the engine. The amount of air density returned depends on a number of factors: ambient temperature of the incoming air, efficiency of the compressors, and the overall cooling capacity of the charge air cooler system itself. If the turbo system is sized properly, and operates at or near its peak efficiency, then the charge will not be heated as much.
As enthusiasts have learned for decades there are always gains to be had over the OE design, especially when it comes to the subject of charge air cooler construction. The factory charge air cooler in the F-150 application is constructed with a tube-and-fin design, much like the radiator in your vehicle. The Vortech charge air cooler, by contrast, uses the bar-and-plate design. The tube-and-fin design weighs less than a bar-and-plate design, but due to the methods of manufacturing trades reduced capacity when compared with a bar and plate cooler of the same footprint size due to the methods of manufacturing. This is where the Vortech cooler improves on the factory’s design in this application.
Bar-and-plate charge air coolers have many advantages over the tube-and-fin design. In this design, the core acts as a heat sink and does a much better job in high-stress situations like towing and stop-and-go traffic. The core will help to keep the charge relatively cool and then dissipate the heat much more quickly once the vehicle begins moving again.
The bar-and-plate cooler has fins that run the full width of the core, so a 3.5-inch core has 3.5-inches of cooling fins, not the necked-down smaller fin counts of the tube-and-fin design. The tube design also has much more room between the rows, where a bar-and-plate unit can fit more cooling fins into a given area due to the construction, which means better efficiency. Our pre-production Vortech charge air cooler uses sheetmetal end tanks. The full-production Vortech unit will use cast end tanks for optimized flow and a factory-like appearance.
As both the factory cooler and our new Vortech cooler are air-to-air units, this installation and test is a true measure of the capabilities of both types of systems.
It’s a natural fit for Vortech to get into a new market like this. The company has made air management their mantra for the better part of 25 years, “The OEMs are pushing more and more towards turbocharging, and since we are an air movement company, we thought it would be a good fit to start offering other alternatives to what the factory has to generate increased performance,”says Vortech’s Lance Keck.
How It Works
There’s a real big heat soak issue with the stock charge cooler, and this certainly helps that. – Lance Keck, Vortech Superchargers
There’s a balancing act required when it comes to designing the charge air cooler. It needs to offer a low pressure drop (boost lost as it moves across the cooler) while retaining the ability to transfer the heat. A high fin count between the plates offers a large drop in charge air temperature, but it also creates a large pressure drop, while a low fin count offers a low pressure drop but not nearly as much ability to transfer the heat out of the cooler core.
The type of fin also comes into play. A plain fin allows the air to pass quickly, but the air may move so quickly that it doesn’t maximize the heat transfer. Conversely, an offset or louvered fin gives the air more time to transfer the heat, but may slow the flow down too much (high pressure drop), which hinders effectiveness.
One more aspect that needs to be taken into account during charge air cooler design is surface area versus core thickness. The balancing act continues here as it’s important to be large enough to effectively transfer the heat, but larger surface area is more important than a thicker core for a number of reasons. The larger surface area provides more cooling area for the ambient air to dissipate heat, while a core that’s too thick can cause the air to heat up through transfer. The further the air has to travel through the core, the hotter it will get, and the less cooling it can provide.
Bar and plate charge air coolers are substantially more robust and will withstand more boost, although that’s not as much of a concern in this application due to the relatively low boost level from the factory.
With Or Without A Tune?
As we mentioned the Vortech folks feel that this vehicle would perform best with an aftermarket computer calibration to maximize performance with the improved intake air temperatures seen after the installation of the new charge air cooler.
In addition, the truck would perform even better with 93 octane fuel, which is unavailable to us in California where the testing was conducted. Horsepower and torque definitely increased with the canned tune we used from the tuner, and would be even better with a true custom calibration in place. The torque numbers are also much more consistent across all four runs.
The Power Automedia tech center team got to work and had the charge air coolers swapped out in under a hour. Since the new Vortech piece uses all of the factory connection points, the removal of a few nuts, bolts, and tubing connections was all it took to disconnect the factory charge air cooler. Installation was the reverse of the removal and there were no special considerations to consider during the process.
“This charge air cooler is designed to bolt into the factory position; any of the factory plumbing, the factory shrouds, all of those pieces fit up with the charge air cooler. There’s a real big heat soak issue with the stock charge cooler, and this certainly helps that. The benefit, and real performance gain will certainly come from some sort of calibration work. Because of the decrease in intake air temperatures you’d have the ability to put more timing in it,” says Keck.
On The Dyno
As with any project the dyno tells the tale. We turned to the Power Automedia Dynojet to measure our gains both with and without the Vortech charge air cooler. Prior to the installation of the new charge air cooler, this truck had been modified with a cold-air intake and a cat-back exhaust system. In completely stock form on 87 octane fuel the truck put down max numbers of 291.4 hp at 5,200 rpm and a max of 345.9 ft-lbs of torque at 4,000 rpm.
With our cat-back exhaust from CORSA Performance and the cold-air intake from AIRAID, we also installed an AIW tuner from Livernois Motorsports and one of the company’s Thunderstorm downpipes as the first level of modifications to the truck, prior to the charge air cooler’s installation. With the tuner onboard, along with the exhaust and CAI mods, the truck was subsequently run on 91 octane and rolled the dyno to max numbers of 335.6 hp at 5,300 rpm (run 3), and 392.5 ft-lbs at 4,400 rpm (run 3) for a substantial improvement in power production over the stock numbers. But – as you can see on the dyno graphs power and torque numbers were inconsistent, which we feel was due to the heat-soak issues that have been a complaint for F-150 owners since the EcoBoost engine debuted in the truck in 2011. Horsepower and torque drops off substantially as the vehicle reaches operating temperature.
Our third round of testing came after the installation of the Vortech charge air cooler, but with all other conditions the same. With the cooler in place and back-to-back runs, the dyno maxed out at 348.0 hp at 5,400 rpm (run 2), and 397.4 ft-lbs at 4,300 rpm (run 4). If you look at the graph from the runs with the charge air cooler, you can see most importantly how the torque stayed relatively equal across all of the pulls, and our highest torque number was basically duplicated on both runs one and four. There are slight variations between all of the runs; this can be attributed to the computer adjusting timing based on conditions and the vehicle working to reach operating temperature.
We attribute the improvement in consistency to the reduction in heat soak; even on the dyno with no supplemental airflow the Vortech charge air cooler is making the truck more consistent and doing a better job of cooling the intake charge. The F-150 has no way for us to data log the intake air temperatures so we can’t show this correlation in a graph. With more consistent power this F-150 is ready for the daily commute, towing, or hauling whatever we want to throw at it thanks to its new charge air cooler from Vortech.