Tommy Boshers' Hellcat-swapped Winnebago, as it appears in the embedded YouTube video. Image: Tommy Boshers/YouTube
The line lock didn’t hold. Tommy Boshers says so himself at the end of his August 15 video, pointing to 40 to 50 feet of black marks laid down by his Hellcat-swapped Winnebago using an old-fashioned power-brake burnout instead.
The video, “Build a burnout button for 700 horsepower winnebago?,” is the latest how-to entry in Boshers’ series on the Hemibago, a vintage Winnebago Brave motorhome with a supercharged Hemi up front. The description promises he’ll install a line lock “and then take the Hemibago out to see if it actually works.” The chapter at 25:45 is titled “The burnout that finally works.” That title refers to the burnout. The part is another matter.
Why a motorhome needs a burnout button
Boshers lays out the problem in the description: 700 supercharged horsepower in front, “four massive one-ton brakes out back.” Mash the throttle without something holding the front of the Winnebago and he expects a part to break. A line lock is supposed to clamp the front brakes alone so the rear tires can spin in place.
He explains the mechanism at 6:23. The kit, from sponsor Summit Racing, is a solenoid valve plumbed into the front brake line. You press the pedal as hard as you can, then push the button. The energized solenoid closes and traps fluid pressure in the front circuit. Lift off the pedal and the rear brakes release, while the fronts stay clamped for as long as your finger stays on the button.
Getting it in takes most of the video. Bending custom hard lines alone runs from 9:55 to 16:26, followed by wiring, finding a spot for the button and bleeding the brakes. Along the way, Boshers pulls a front wheel to reach the master cylinder and points out that the lug nuts are reverse-threaded, something he says Dodge did in the late ’60s and early ’70s. Turn them the usual way, he warns, and “you’re twisting studs off.”
What happened on the road
The first test starts at 20:59 and doesn’t go his way. A few minutes later he concedes the “roll control may not be able to hold these front wheels” and decides to try a “standard old power brake kind of burnout.” That’s the one that left the stripes.
His diagnosis comes right after. The front tires “get a little light when it launches,” he says, and once they lift they stop biting and start rolling. “We may have met and exceeded the limitations of that little roll control.” A line lock can only clamp the front brakes. It can’t add grip at the tire, and when the nose of a motorhome rises under 700 hp, the front tires have less of it to give.
The video leaves out the numbers you’d want to judge that. There’s no weight for the Winnebago, no model year, no transmission or rear-axle spec, and no dyno sheet. Boshers also never says whether the engine is a Direct Connection Hellcrate or one pulled from a donor car. For reference, Stellantis’ October 2023 Direct Connection release lists the Hellcrate 6.2-liter supercharged long block at 717 hp and 656 lb-ft, with a $9,495 MSRP. Boshers uses 700 throughout. We’ve seen the same engine family go into a 1971 ‘Cuda convertible, a 1972 Dodge Demon and a 2001 Viper that sold for $33,250.
The driveshaft went next
Five days later, Boshers posted “Hellcat Hemi Destroys Driveshaft,” a 55-minute teardown. According to its description, the two-piece driveshaft “just about tore itself out from under the Hemibago mid-launch.” He found bluing on the U-joints, an egg-shaped cup and a second U-joint that had failed as badly as the first. The chapter list names the part, a non-greasable Spicer 1350X, and puts a question mark on the suspected cause: over-tightened U-bolts at the pinion yoke.
That chapter list still carries a production note that reads “pulled from the raw footage timeline — adjust to match your final cut.” Nobody adjusted it.
The audience has already voted on which Hemibago content it wants. The August 8 burnout video, which promises “Full launch!” and tires shredded “in the middle of town,” had 187,405 views when we checked. The line lock install had 28,870.
The driveshaft episode ends with new U-joints installed and the shaft back under the motorhome, and its description says Boshers will be at MoParty in Bowling Green. It doesn’t say whether the Hemibago is coming, or whether the line lock stays on it. Should he keep chasing a line lock that can hold a 700-hp motorhome, or accept that the power-brake burnout already did the job?
Sources: Tommy Boshers, “Build a burnout button for 700 horsepower winnebago?” (YouTube, Aug. 15, 2026); “Hellcat Hemi Destroys Driveshaft” (YouTube, Aug. 20, 2026); “Burnouts 700hp RV HEMIBAGO” (YouTube, Aug. 8, 2026); Stellantis/Dodge Direct Connection crate engine release (Oct. 31, 2023).
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