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Adding Power Options To a Powerhouse | H&S Performance's Mini Maxx Installation

Posted in How To on January 1, 2013
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So far our new 6.7L Power Stroke Super Duty truck is living up to every demand we’ve made of it and running flawlessly to boot. While our plan is and has always has been to leave everything basically stock under the hood of our ’11 F-250, we figured a mild tune on our truck couldn’t hurt matters. Four hundred horsepower and 800 lb-ft of torque (straight from the factory) is more than enough for any legal pulling duties we’ll ever do with our truck, but we’ve discovered that we are those greedy types that are never quite satisfied, no matter how much power we’re given.

We’ve never had a truck this nice before, and we naturally wanted to match it to the best tuner (for our truck) that we could find. We didn’t want (or need) anything too extreme, and a switch-on-the-fly tune is preferred over a full flash on our ECU—especially since it’s illegal in many states to have any modified tune downloaded while driving on public roads.

Besides wanting a tad more power, there are a few things we wanted to adjust and/or disable on our truck, and an on-board tuner is the easiest and best way to perform these actions.

PhotosView Slideshow

So we asked around: diesel specialists, work associates—anyone who might know what the best tuner option is for the new 6.7L Power Stroke diesel. When we were given three identical suggestions by the first three people we asked, there was no question that we’d be going with H&S Performance’s Mini Maxx in our new Super Duty.

After three months of having the H&S tuner on our 2011 Super Duty, we can tell you that it’s exactly what we wanted for our truck, and more. The Mini Maxx is the small, easy-to-use, immediately adjustable, impressively effective tuner that fit our F-250 perfectly.

04. Upon punching in the “unlock” code and the Mini Maxx reading the ECU files, you can change a number of options. If you’re racing your diesel truck, you can use the Mini Maxx to disable the EGR system, the DPF, or the UREA system. Tire calibration is available if you have lifted your truck and added larger tires. You can adjust the speed limiter or remove it completely. You can clear DTCs (diagnostic trouble codes). And we were able to disable the TPMS (tire pressure monitoring system) that just beeped at us all the time. The TPMS is adjustable via the Mini Maxx, but we were happy to just disable it.

05. There are four power levels available. “No Power” means the Mini Maxx is simply being used as a monitoring system; “Mild” gives a 40hp bump to the engine; “Wild” raises engine power an extra 80 horsepower; and “Hot” gives a 120hp boost. When off public roads and in Hot mode, our Super Duty is blindingly fast. The Mini Maxx is equipped with an auto safety backdown system that drops all power levels back to stock if it senses something like a spike in engine coolant temperatures. Towing in the Wild power level, we were able to trip the safety alert while climbing a long, steep grade on a hot day with a heavy trailer. The tuner flashed the words “no power” and indicated a higher coolant temperature.

No Power 0 hp
Mild +40 hp
Wild +80hp
Hot +120 hp


Besides being a power adder and a DTC reader, the Mini Maxx performs excellently as a vehicle-monitoring system. At any one time, four different readouts are displayed for monitoring vehicle parameters. You can also choose one of the four readings as the primary gauge readout—we keep ours on Pyrometer 2 since we have accurate boost and coolant temperature gauges embedded in the factory dash.

The Mini Maxx gives you the option of watching:
  • Current power level
  • Transmission gear position
  • Torque converter status
  • Pyrometer 1
  • Pyrometer 2
  • Speed
  • Boost pressure
  • Engine RPM
  • Coolant temperature
  • Throttle percentage
  • Intake air temperature
  • Barometric pressure
  • Battery voltage
  • Oil temperature
  • Fuel rail pressure (ICP)
  • Transmission temperature (Auto)
  • Load percentage
  • Exhaust back pressure
  • Injection timing
  • Estimated torque

Kill Option

Normally, we drive around in either the Mild setting or down to No Power if we’re just sitting in traffic. We really like being able to change the tuning while the truck is moving down the road with just the push of a button, for almost immediate power increase (or decrease) when necessary.

In Hot mode, this is one fast truck.

We do know of one basically stock 6.7L (similar to ours) that runs the Mini Maxx in the Hot power level and has verified that the truck (in 4WD) will outrun a new Subaru WRX in an eighth of a mile. The WRX will gain and pass before a quarter-mile track is over, but the Super Duty (in 4WD with the Mini Maxx on Hot) will have the upper hand up to 60 mph.


H&S Performance

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