Choosing The Right Alternator For A High-Horsepower LS Build

Big horsepower always gets headlines, but anyone who’s built a big horsepower vehicle knows that reliable voltage is just as important as things like boost, compression, and camshaft selection. That’s especially true when you’re building a truck like Big 10, which competed in our epic YouTube series Horsepower Wars. For that shootout, every system had to work flawlessly under the pressure of competition, and that’s why the Big 10 team turned to Powermaster for all their charging needs. 

We all know that overall consistency of performance wins races, and that means a high-quality alternator is one of the most important parts of a high-performance build. Modern engines like the LS rely on a constant electrical supply to keep the ECU, ignition coils, injectors, electric fans, fuel pumps, and data acquisition systems operating at peak efficiency. That means a sudden voltage drop doesn’t just cause annoying issues like dim headlights; it creates more significant problems, such as poor injector performance and weakened ignition strength. According to the pros at Powermaster, performance ignition systems operate best in the 13.8 to 14.8-volt range. That means having a strong charging system is critical on anything with a serious EFI setup.

The Big 10 Chevy certainly qualifies as “serious.” To support the truck’s killer LME drivetrain, the builders paired a 220-amp high-output Powermaster alternator (PN 48237) with an ICT Billet accessory drive, an Optima OrangeTop battery, and Moroso cables, terminals, and disconnect hardware. Simply put, the goal was to provide stable voltage regardless of the demands the truck encountered during testing and competition.

With Big 10, choosing a 220-amp alternator was about ensuring the electrical system always had reserve capacity. High-output electric fans, EFI fuel pumps, ignition systems, and engine management all compete for amperage, especially at idle or during repeated dyno pulls. An undersized alternator forces the battery to pick up the slack, while a properly sized unit keeps the battery charged and the entire system operating consistently. The Powermaster 48237 is built around the proven AD244 platform, delivering 220 amps at peak output and roughly 140 amps at idle, making it well-suited for demanding street and race applications where electrical loads rarely let up.

In a competition like Horsepower Wars, consistency is everything. Every horsepower number, every tuning change, and every pass depends on the electronics working exactly as intended. The Powermaster 48237 alternator may not have been the flashiest component on Big 10, but it quietly ensured the truck’s LS combination had the stable electrical foundation it needed to perform. Often, the most important aspects of a build aren’t the parts bringing the noise; they’re the parts making sure everything else can bring the noise.