We Took Our Demon 170-Swapped HELLCAT to the Track – Here’s What Happened

Last week, we gave you an inside look at our Demon 170-swapped 2015 Dodge Challenger SRT HELLCAT project—the culmination of a massive transformation that blends OEM performance with aftermarket ingenuity. Now, we’ve finally brought it to the drag strip to shake it down and gather crucial data for refining the tune.

Full Demon 170 Wiring. Full Potential – 

This isn’t just a cosmetic swap. Our HELLCAT now runs on full Demon 170 wiring, PCM, and supporting modules. That means we’re able to tap into one of the most important features of the modern Mopar performance ecosystem: factory-supported flex fuel. Whether it’s pump gas, E85, or even E98, we now have the freedom to run what we want.

Fuel System Bottlenecks Revealed – 

But with great power comes… limitations. On our first full hit with E85 in the tank, we discovered that our dual-pump setup simply couldn’t keep up under full throttle. The result? Fuel starvation. As a quick fix, we diluted the ethanol content with pump gas and switched to a boost-limited tune. That allowed us to gather clean data without pushing the system beyond its limits.

Traction Troubles & Aging Tires – 

While the power delivery was strong, traction was our biggest enemy all day. Our Mickey Thompson ET Street R 315/60/15 drag radials—now three years old—struggled to get the car to hook, especially before the 330-foot mark.

Even so, the car still managed to clock a new personal best in both ET and MPH. That speaks volumes about the sheer capability of this setup, even under less-than-ideal conditions.

What’s Next? Fresh Rubber & Fine-Tuning – 

We’ve only just scratched the surface of this combo’s potential. New drag radials are already on the way, and we’ll be looking at suspension tweaks and additional tuning refinements before our next outing. There’s no doubt in our minds this car is capable of running significantly better ETs once everything is dialed in.