The Stage 5 Harbor Freight Predator with a Turbo and EFI is the ultimate go-kart engine.

      Red Beard Garage on YouTube

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      I’ve reached a stage in my life where Harbor Freight Predators pique my interest more than LS engines. While they can't compete with GM's affordable performance favorite, you won't see them swapped into almost every classic truck and hot rod (save for the occasional Honda Insight or Chinese UTV). Then there are people like those at Red Beard's Garage on YouTube, who constructed a 670cc Predator, featuring a turbo, billet pistons and connecting rods, electronic fuel injection, and much more. How could you not be captivated?

      This individual tackles all sorts of tasks involving small engines. You can watch him experiment with single-seat go-karts, like the intriguingly named Yerfdog Spiderbox, in addition to modified pit bikes. However, this V-twin project might be the most ambitious endeavor he has undertaken when it comes to significant speed enhancements.

      Numerous aftermarket suppliers offer support for the 670cc Predator, providing Red Beard’s Garage with plenty of options. Along with the turbo he purchased from Amazon—typically used to power Bobcat skid steers and Doosan forklifts—he’s using a well-known Holley Sniper EFI, as well as billet rods and pistons, a billet flywheel, roller rocker arms, electronic ignition, and an upgraded 507 camshaft from Performance Machine and Design. The head modifications were done by Beckwith Performance, a friend of the shop that specializes in Predators, as well as Briggs and Stratton and Kohler engines.

      Given that a stock 22-horsepower Predator 670 is priced at $949, the cost of these parts can easily surpass that amount. Fortunately for Red Beard, many of these upgraded components were acquired used, saving him some money. You might also stumble upon similar deals, but keep in mind that this project isn't as budget-friendly as adjusting the carburetor on your minibike.

      Red Beard’s Garage on YouTube

      Any DIY enthusiast will appreciate that the host meticulously covers every aspect of the build, with slightly sped-up footage and on-screen captions detailing the tools he's using. The relaxed voice narration is easy to follow as well. Coupled with stable camera work, it makes for enjoyable viewing.

      Red Beard intends to run 12 psi of boost through this engine, which should provide a substantial performance increase. It remains unclear how much power it will ultimately generate. He already has a supercharged Predator-powered go-kart that runs at 14 psi, and it’s quite lively. Once the turbo build is completed, he plans to race the two against each other to determine the winner.

      Regardless of the outcome, I’m all in favor of boosted Harbor Freight engines.

      Stage 5 670cc Turbo EFI Engine Build

      Have a tip or question for the author? Reach out directly: caleb@thedrive.com