Nitto Trail Grappler Tires

Sunday, May 01, 2011

The time has come to get more aggressive with our ’11 Super Duty’s performance. So far, we’ve added power to the 6.7L Power Stroke while retaining the diesel particulate filter (DPF), selective catalytic reduction (SCR), and exhaust gas recirculation (EGR) systems. Now, we’re removing all three in order to pave the way for more performance. After getting our hands on one of H&S Performance’s Black Maxx tuners over the winter, we conducted some street and dyno testing.

With a freer-flowing exhaust thrown into the mix, an uncorrupted intake tract, and more rear wheel horsepower, we’re formulating our next power-adding attack. Stay tuned, because in the following months the horsepower level will only be climbing.


On the dyno, the Super Duty laid down 875 lb-ft at just 1,900 rpm, and torque didn’t fall below 800 lb-ft at the wheels until 2,700 rpm (which explains why the truck pulls so hard on the street). Our horsepower curve shows a different story, however. Notice the dip in our power curve at 2,800 rpm? This is because rail pressure dropped from 29,000 psi to 22,800 psi and recovered once the truck pulled through the load the dyno had placed on it. According to H&S, the drop in rail pressure we saw may not occur on every truck. In addition, H&S has stated that some tuning changes should prevent this problem from occurring on any trucks in the future. *All results are shown using the Society of Automotive Engineer’s (SAE) correction factor. All dyno pulls were made in Fifth gear, and with traction control off. All tests started at 52 mph and ended at 95 mph.

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