Let's talk power! Our first set of runs established our baseline. The F150 made 256.9 HP and 339.3 LB/FT TQ at the wheels. If those numbers seem low, remember that you cannot compare dyno results from different systems or even different days.
Long term readers know that we like the SuperFlow dynomometer for its ability to better replicate real-world driving conditions through load generation. Remember, the most important thing is the difference between each before-and-after run. Not the peak numbers.
The results with just the MagnaFlow 4″ exhaust system were quite good! As a comparison of peak values to the results with the stock F150 exhaust, we saw gains of 17.3 wheel horsepower and 12 foot pounds of torque!
Dyno runs were made to establish baseline horsepower and to measure the gains made with the MagnaFlow four inch exhaust system, but we also made some bonus runs to show you what a simple tune can do when combined with a large diameter exhaust system.
The folks at 5 StarTuning caught our attention since they create a bespoke tune for each customer. You just visit their site, tell them about your rig, and you'll receive your tunes by email! Many popular handheld controllers are supported, including our SCT X4.
We started modestly with their 91 octane map. If you're worried about what happens when your truck is under full load — like towing on a hot day up rolling hills, they have that covered too! We chose an especially conservative 87 octane “tow map” for such purposes (but always use the best fuel available for cheap insurance).