This is my street-legal jet car on full afterburner. The foundation of this unique machine is a Volkswagen Beetle, often affectionately called a Volkswagen Buggy, but with a twist that sets it apart from any other buggy you’ve ever seen. This isn’t your average modified car; it’s a dual-engine marvel, boasting a standard production gasoline engine driving the front wheels and a powerful jet engine mounted in the rear.
The concept was simple yet audacious: daily driving powered by the gasoline engine, and unleashing jet-fueled exhilaration at will. Imagine cruising legally, then, with the flip of a switch, igniting a jet engine to experience true afterburner thrust. This project wasn’t about following trends or replicating past builds; it was about pushing boundaries and realizing a vision of the wildest street-legal ride imaginable. My background, a PhD in Mechanical Engineering from Stanford University, provided the perfect toolkit to design this one-of-a-kind street-legal jet car from the ground up, unconstrained by conventional approaches because, quite simply, nothing like this had ever been attempted before. Top speed? Unknown, and perhaps intentionally so. This Volkswagen Buggy was engineered for thrills, not reckless abandon, though the occasional high-speed run on the highway is undeniably part of the experience.
Legality was paramount. Registered and licensed in California, this Volkswagen Buggy navigated the state’s stringent vehicle regulations. California’s bi-annual smog inspections pose a significant hurdle for engine modifications. While minor, inconsequential changes might pass, adding a 1350 horsepower jet engine to any new car is decidedly not a minor modification. This project required meticulous engineering and adherence to legal boundaries to ensure it remained street-legal.
A key design principle was to maintain a factory-like aesthetic. The goal was for this Volkswagen Buggy to appear as if it could have rolled straight out of a VW factory, albeit a very special one. The handling and safety of the car were never compromised. Interestingly, the subdued appearance initially missed the mark with some. A promoter at an import car show suggested aftermarket wheels, decals, and lowering the suspension. The response was a firm rejection of such superficial modifications. The focus was on engineering substance, not fleeting trends. The sheer presence of a 14-inch diameter tailpipe should have been statement enough. Hot rod magazines were initially hesitant, perhaps due to the lack of advertised aftermarket parts, but the public response has been overwhelmingly positive. Appearances at shows like the San Francisco Custom Car Show, the Grand National Roadster Show in Pomona, and the Detroit Autorama have proven this Volkswagen Buggy to be a crowd magnet, outdrawing even classic ’32 Fords, ’69 Camaros, and decal-laden Hondas.
The choice of the Beetle, or Volkswagen Buggy, as the base vehicle was deliberate. Its iconic shape and readily recognizable silhouette provide the perfect canvas to showcase the jet engine. Think of it as the “Jet Under Glass” counterpart to the famed “Hemi Under Glass” wheelstanding Barracuda. Airflow for the jet engine is ingeniously channeled through the car’s side windows and sunroof. While it does create a breezy interior, it’s a small price to pay for jet-powered performance.
Even practical details were meticulously engineered. The factory hatch release switch on the driver’s door now controls custom latches, allowing the rear hatch to pop open just like a standard production car. The original “hatch not closed” warning light even remains functional, a testament to the attention to detail.
The immense power of the jet engine is not without its challenges. A particularly forceful afterburner pop resulted in a split tailpipe, now repaired and reinforced. A heat blanket is strategically placed to protect the plastic bumper from the extreme temperatures generated during jet operation, a crucial detail for maintaining the car’s integrity.
The gauge panel’s rear is deliberately left open, showcasing the intricate engineering within. It’s a conversation starter, a visual representation of the car’s engineering heart. Designed in SolidWorks and meticulously crafted from billet aluminum, the panel features bead blasting, clear anodization, and milled switch labels using a font that mirrors the original VW cluster. Small details, like flat-sided holes preventing switch rotation and precise contour matching to the dash, demonstrate the dedication to craftsmanship. Multiple styrofoam prototypes were created to perfect the layout and lighting. The panel’s aesthetic is reminiscent of the 1970s McLaren CanAm cars, adding another layer of automotive history to this unique Volkswagen Buggy.
The transformation began with a bold step: cutting the hole for the jet engine. A custom jig, fashioned from a tripod, rod, and lawnmower wheel, ensured precise marking for the cut. A pneumatic saw made the initial incision, followed by jeweler’s files for fine-tuning. Remarkably, no paint touch-up was needed, and the original finish remained unblemished. The hole’s complexity, cutting through three layers at angles, demanded precision. Even finding the car’s centerline was a challenge. The potential reaction of neighbors to a ruined brand-new car added to the pressure, resulting in a cut accurate to within 2mm.
Three gauges monitor the jet engine’s vital parameters: %RPM, Oil Pressure, and Turbine Inlet Temperature. Turbine Inlet Temperature is critical; exceeding 650 degrees Celsius for extended periods can damage the engine, especially during startup, where a “hot-start” must be avoided. The jet engine throttle, a lever with “Cool,” “Big-Fire,” and “Afterburner” buttons, is strategically placed next to the gear selector. “Cool” leans out the engine to manage turbine inlet temperature during hot starts. Activating “Big-Fire” or “Afterburner” involves holding a button and then pressing the “hot-streak” button on the floor, unleashing the jet’s full potential. A kerosene level gauge, essential as jet fuel is primarily kerosene, is positioned in front of the gear selector, next to an empty bud vase, its rose a frequent casualty of jet engine intake.
The jet engine’s immense thrust is securely anchored to the Volkswagen Buggy’s chassis via internal sandwich plates bolted to contoured aluminum billets slid into the frame rails. A visible billet, welded with helium and high current, showcases the robust construction. Adjustable spring perches maintain the car’s original ride height and handling characteristics. The custom 14-gallon kevlar fuel cell, baffled and foam-filled, resides in the spare tire well, storing kerosene. Two fuel exits feed the engine and afterburner systems, utilizing high-performance pumps and components, including a Barry Grant pump, one of the few aftermarket hot rod parts on the car. The fuel system, meticulously plumbed with filters, regulators, and electrical shutoffs, was rigorously tested for flow capacity. Relocated gasoline cap actuator and stock fuel evaporative control equipment are also visible, demonstrating the integration of both fuel systems. All electrical circuits are protected with fuses, relays, kick-back diodes, and sealed connectors, ensuring reliability and safety.
Powering this incredible Volkswagen Buggy is a General Electric Model T58-8F engine. Originally a helicopter turboshaft engine, it was expertly converted into a jet engine with internal modifications and a custom tailpipe. This engine roars to 26,000 RPM (idle at 13,000 RPM), draws a massive 11,000 CFM of air, and delivers a staggering 1350 horsepower, all while weighing a mere 300 lbs. Engine mounts accommodate thermal expansion, with rubber mounts at the front and sliding mounts at the rear. The engine structure, designed with finite element analysis, is both strong and lightweight. A secondary battery, fuse/relay panel, halon fire system, and a 5-gallon dry sump tank are neatly integrated. The 24V starter motor draws an immense 700 Amps for 20 seconds during startup, necessitating cool-down periods between starts. A protective screen prevents Foreign Object Damage (FOD), crucial for jet engine longevity. The jet’s powerful intake has a humorous side effect: it repeatedly sucks the rose out of the dashboard bud vase.
Attention to detail is evident throughout the build. An aluminum block securely holds and protects critical lines: halon gas, pull line, engine harness, and oil pressure. A rectangular tank collects fuel drains. Temperature gauge and shutoff valve for the dry sump tank are readily accessible. The engine uses 3 gallons of turbine oil at a premium price. The interior is finished with a two-stage PPG paint matching the car’s exterior, a challenging application in a home garage environment. Despite the fumes and cramped conditions, the paint job turned out flawlessly.
Street encounters often turn into impromptu demonstrations. A “big-fire” display is usually enough to deter any challengers. The fireball shown is only a fraction of its full size. Spectators are invariably amazed, their reactions ranging from stunned silence to ear-to-ear grins. Launching the car with full afterburner in close proximity would be, shall we say, inadvisable.
Police attention is a common occurrence, often leading to bemused officers trying to decipher the legality of a jet-powered Volkswagen Buggy. The California DMV, however, proved resourceful, reportedly requesting a federal agency to assess whether this unique Beetle poses a national security threat. This raises some interesting questions: Does this imply the owner is trustworthy? Could a high eBay bid from someone with a questionable username be refused? And more importantly, would that impact eBay feedback?
This extraordinary Volkswagen Buggy was brought to life in a home garage. From paint to welding, nearly every aspect was completed personally, except for some machining work. Pictured is the engine undergoing fuel controller maintenance. The orange lines are for the afterburner system. The engine’s front reveals the four rows of variable inlets/stators, adjusting angle with engine speed to prevent compressor stall. Inside, there are 11 compressor stages and 2 turbine stages, achieving a pressure ratio of 8.3:1. Jet engine maintenance is simplified by mounting it vertically, a convenient method for both work and storage.
The spirit of extreme modification extends beyond cars. The next project? Boosting the performance of a Honda Metropolitan scooter for his wife, aiming for speeds exceeding 40 mph. The solution: two small JFS 100 jet engines. Weight is a concern, but air-start with a carbon fiber compressed air tank is being considered to eliminate the need for heavy batteries.
The twin jet engine setup on the scooter has a visually striking appearance, reminiscent of a miniature DC-9. Aluminum housings are planned to further refine the integration and aesthetics.
Even in its early stages, the jet-powered scooter project looks promising. A single JFS 100 engine can propel a kart to 60 mph, suggesting significant performance gains for the scooter. Spare wiring from the Volkswagen Buggy project will likely be repurposed for this new endeavor, continuing the legacy of extreme, jet-powered creations.
