An extra 50 wheel horsepower, all without adding forced induction.
As a rule, it's easier to pull more power out of a stock forced-induction motor than a naturally aspirated one; all you have to do is crank up the boost (within reason).
But legendary Detroit tuning shop Livernois Motorsports & Engineering took a different approach with the Ford Shelby GT350 Mustang recently. The track-focused Mustang benefits from a high-revving, high-compression 5.2L "VooDoo" V8 with a flat-plane crankshaft, capable of better than 100 horsepower per liter with no forced induction. The unique, charismatic character might well have been spoiled by the addition of turbos or a supercharger, but all those attributes make the VooDoo a perfect candidate for a high-octane fuel tune - in this case, an ethanol-pump gas blend.
In the video above, Livernois Motorsports talks through the basics of the tune, which allows the track-focused GT350 to take full advantage of fuels ranging from 0 to 85 percent ethanol by volume. Ethanol has a higher overall power potential than gasoline thanks to its higher octane rating, which allows the spark timing to be advanced for a more complete burn.
The net result is an extra 48 peak horsepower at the rear wheels on E85, and total flex fuel capability. That's right: this tune can automatically acclimate to whatever is in the tank, so long as it's at least 15% pump gas.
For reference, that's about an extra 35 to 40 wheel horsepower more than the Detroit outfit's 93-octane tune for the Shelby GT350.
Granted, sticking with natural aspiration has its limits; a piston engine can only inhale so much atmosphere without assistance. To make truly big power, forced induction is pretty much essential. A package from Hennessey Performance Engineering, for instance, boosts the 2016-2020 Shelby GT350 to some 858 crank horsepower using a big twin-screw supercharger and high-flow air induction components.
Still, it's amazing what Livernois Motorsports has been able to accomplish on a stock naturally aspirated GT350 motor, with little more than software.