LokJaw’s wheel problem is packaging first. The front can’t be wider than 8.5 in. if we want usable steering, and the rear offset has to be right or the wheel hits the bed when the truck drops. On top of that, we want the wheel to do more than fill the opening. The design is being pushed toward moving air through the rotor and out the face of the wheel, while still showing the 8-lug pattern and the Wilwood brakes. That means starting from scratch. We worked with Sparc Industries around wheel concepts that use large openings, fan-like blade shapes, and side-specific rotation to help extract air instead of trapping it. The goal is function first: brake cooling, cleaner airflow around the truck, and the right clearances for a bagged chassis. Because forged wheel lead times were too long for the build schedule, the plan is a one-piece billet aluminum wheel machined from solid material, with the spoke-to-rim areas designed around the different structural demands of extruded stock. This is what happens when the truck dictates the wheel instead of the catalog.
The episode centers on a packaging problem with Banks' supercharged Duramax-powered, eight-lug Chevrolet project truck, Lockjaw. No off-the-shelf wheels fit the combination, so the team decides to commission a completely custom set. The truck is an intentionally rough, heavily corroded build rather than a polished restoration, but it is also meant to showcase Banks engine technology and the engineering direction of upcoming powertrain work. Because of that, the wheels cannot be treated as cosmetic parts alone; they need to contribute functionally to airflow and brake cooling.
To solve the problem, Gale and the Banks team meet with Jonathan Peace of Spark Industries, along with Matt Gamble and Eric Ryder. Spark is known for steering wheels, but the discussion quickly establishes that the company also designs and manufactures road wheels. Gale references the shop's past high-end work, including the award-winning Thunderbird that won the Ridler in 2012. That car had started as a family restoration project for Jonathan's father, but it evolved into a much more ambitious build involving Jonathan, Matt, Jonathan's brother, and their father.
The Thunderbird also carried one of Gale's twin-turbo 6.0-liter engines, which Gale notes was an unexpected honor in a Ridler-level car. Jonathan explains that even details such as the car's logo were custom-designed, blending original Thunderbird cues with more modern proportions. The conversation establishes Spark's design pedigree before shifting back to the much rougher Lockjaw truck, where the challenge is not elegance alone but combining appearance with measurable function.
Banks presents the core requirement: the wheel should actively process air. The goal is to help move air through the brake package, across the rotor, and out through the wheel face. The team is not trying to dictate the final styling to Spark, but they have already built some preliminary CAD concepts to communicate the engineering intent.
Those concepts begin with an eight-lug layout, large openings, and an eight-spoke theme. The design has to balance several competing priorities. It must preserve enough open area to show the Wilwood brakes, visually acknowledge the eight-lug hub pattern, and still create useful airflow. Matt explains that the early SolidWorks models were not final designs but conversation starters meant to visualize how the wheel might become an active aerodynamic device rather than a passive rim.
The first concept starts as a basic eight-window wheel, but the team quickly concludes that this simple arrangement does not meet the airflow objective. They then experiment with shapes that turn the spokes into airfoils, effectively making the wheel behave like a fan. Gale points out that once the spokes become airfoils, they are no longer really spokes in the conventional sense.
The dimensions discussed are specific. The wheel mounting flange diameter, where the wheel mates to the hub flange, is 8.700 inches. The wheels are planned as 22-inch units using an 8-on-180 bolt pattern. One of the more aggressive concepts resembles a turbofan or jet-engine-inspired wheel. Because such a design would actively pump air, it would require dedicated left- and right-side versions so rotation pulls air in the intended direction. Gale emphasizes that the wheel should pump air outward, not inward.
Another concept moves away from the pure turbofan look and tries to retain more visual mass and a recognizable eight-spoke structure while still encouraging airflow through the brake area. The team discusses whether the wheel should inhale air from the outside or draw from the inside, and Gale argues for a closed outer face that would encourage the wheel to draw air from the inboard side and then discharge it centrifugally. The objective is to move air through the rotor and caliper region and then out into the lower-pressure area around the front of the vehicle.
The airflow discussion expands beyond brake cooling into vehicle aerodynamics. Gale notes that the front of a vehicle typically creates a low-pressure region as the bow wave breaks away from the nose, and that pressure differential can help extract air through the wheel. On an older truck like this 1966 Chevrolet pickup, aerodynamics are especially poor. He describes the truck as essentially a soap bar, with little aerodynamic refinement and a very rough underside.
That rough underbody matters because the interaction between the road surface and the bottom of the vehicle can generate substantial drag. Gale argues that reducing air density under the truck is beneficial for several reasons, including drag reduction and potentially improved stability. If the wheels can help extract air from beneath the truck at speed, they may contribute not only to brake cooling but also to a small amount of downforce effect during cornering. Jonathan agrees that using the wheels to influence airflow under the truck could make them meaningfully more functional than ordinary wheels.
The wheel design is also constrained by chassis packaging. The front wheels are limited to 8.5 inches in width because of steering clearance and the truck's lowered, frame-dropped configuration. Everything has to clear the tubs during turning. The rear has much more room, so the team expects to use a wider wheel there, likely around 10.5 inches. Earlier in the discussion, a 10-inch rear width is also referenced, but the broader point is that the rear package will be substantially wider than the front.
Offsets will be critical because they determine how much freedom Spark has in shaping the front face and internal contours of the wheel. The final wheel cannot be designed in isolation from the truck's suspension, brake package, and body clearances. The visual design, airflow path, and structural sections all depend on those fitment numbers.
When Gale asks about manufacturing, Jonathan explains that the schedule rules out the usual forged-wheel supply chain. Lead times for forged centers or hoops are running roughly 20 to 24 weeks, which does not fit the Lockjaw timeline. Because the truck is being built on a SEMA deadline and needs road time before the show, Spark plans to machine the wheels from large solid blocks of aluminum instead.
Jonathan is clear about the tradeoff. A forging is structurally preferable because the grain flow follows the shape of the wheel, improving strength in critical areas. With extruded or billet-derived material, the grain direction begins as a single orientation, so the spoke-to-rim transitions and other highly loaded regions must be designed more carefully. Since this project will use a one-piece wheel machined from solid material, Spark will have to compensate through geometry and section design to ensure adequate strength for high-speed use.
Gale specifically asks whether Spark accounts for the difference between forged and extruded material when designing the spoke-to-hoop junction, and Jonathan confirms that this is a major consideration. The wheel must remain structurally sound despite the material compromise imposed by lead times.
The collaboration will proceed through shared CAD and iterative design exchange. Matt proposes sending native SolidWorks files or STEP files so the teams can move back and forth efficiently and finalize the wheel quickly enough to begin machining. Jonathan says his own workflow starts with loose ideation sketches and then moves into CAD, but he does not use SolidWorks. Instead, he relies on a different program that he considers part of his trade-secret process because it allows him to create more organic automotive surfaces than conventional solid-modeling tools typically permit.
That capability is especially relevant for this project because the wheel's airflow performance depends on sculpted, blade-like forms rather than flat spokes. Jonathan also notes that his five-axis CNC machine will let him reach complex surfaces and undercuts that a typical three-axis machine could not access. If the final design requires a fully developed blade shape with machining all the way around it, his equipment can produce it. The plan is to combine Banks' engineering models and airflow intent with Spark's surfacing and machining expertise to create a wheel that works mechanically, fits the truck, and suits the overall styling.
The project is under a tight SEMA schedule. Lockjaw is intended for the AMSOIL exhibit, so the wheel design, machining, and validation all have to happen quickly enough for the truck to be driven and tested before the show. Both sides acknowledge that this kind of deadline pressure is typical of major automotive builds, but it adds urgency to every design decision.
The episode closes with the expectation of continued back-and-forth between Banks and Spark as the wheel concept evolves from rough CAD studies into a manufacturable one-piece aluminum design. The next installment will shift back to the truck itself, where the team continues fabricating the large air boxes and integrating them with the radiator core support in a very tight package.