Our favourite of the three Ringbrothers cars unveiled at SEMA Show 2024 is this 1987 Buick Grand National known as INVADR. The twin-turbocharged Buick produces 1246hp and 1000lb-ft of torque to the rear wheels in daily-driver trim, with much more in reserve.

Ringbrothers invested 5000 hours to take Buick’s legendary G-body to new heights. The Grand National retains its signature angular design but has added touches that subtly highlight the extensive customisation. Originally plastic, both the front and rear bumpers were fabricated from stainless steel and feature machined aluminum bumper guards.

The angle of the front fenders has been adjusted slightly and now seamlessly integrates with the new bumpers, while the rocker panels have been extended, furthering the integrated look. The factory hood was retained, but a Ringbrothers-designed carbonfibre scoop was crafted to assist with heat extraction and enhance the design aesthetic. Covering the body is a custom BASF Glasurit Waterborne mix, fittingly called “Dark Vader Gray.”

“This car is all about presence. The bodywork is subtle at a glance, but the ferocity of what’s under the hood begins to materialise on second viewing. And then you drive it,” said Ringbrothers co-owner Mike Ring. “The acceleration of this car is nothing short of violent. This may well be the fastest car we’ve built to date.”

The Grand National’s centrepiece is its engine. Built by Duttweiler Performance, the 3.8-litre V6 is capable of producing up to 2000hp at 50psi boost. For the current tune and daily driving, the twin Precision 62mm turbochargers produce 32psi boost for a still potent 1246hp on E85. The all-aluminium engine block features six-bolt mains, custom hand-ported aluminium cylinder heads, a billet crankshaft from Bryant Racing, and a bespoke intake manifold. Channelling that power to the tarmac is a Bowler Tremec T56 Magnum six-speed manual transmission mated to a carbonfibre drag-race shaft.

INVADR’s drivetrain sits on a custom Roadster Shop chassis and four-link rear suspension with Penske three-way adjustable shocks at all four corners, ensuring handling and ride comfort. Taming the ferocious power are Brembo brakes with six-piston calipers clamping down on 394x36mm carbon-ceramic rotors. The brakes are tucked behind a set of 19×10.5-inch and 20×13-inch three-piece 528-series wheels from HRE wrapped in Michelin Pilot Sport Cup 2 tyres. Additionally, the underside features an integrated nitrogen-powered air-jack system that raises the car 15.1 inches, enabling quick tyre changes.

The custom interior showcases uncompromised attention to detail while maintaining period-correct design cues. The team at Upholstery Unlimited hand-fabricated the seats, dashboard and center console, while Dakota Digital provided custom instrumentation. Reconfigured floorpans enhance interior comfort, and a Ringbrothers carbonfibre steering wheel complements the balance of power and craftsmanship.

“INVADR is one of those cars we’ll remember building for a long time,” added Ringbrothers co-owner Jim Ring. “It’s a combination of state-of-the-art fabrication and imagination plus the Grand National’s DNA, culminating in an incredible final product. None of this would have been possible without our partners Gentex, HRE Wheels, BASF, Dynamat and more. We are grateful for their continued collaboration with our team.”

Ringbrothers offers a host of products for the Grand National and G-body, including hood and trunk hinge kits, steering wheels, universal parts and more. Visit www.ringbrothers.com for more details.

SPECS:

Major Modifications

• One-off intake manifold with port-matched cylinder heads
• Custom headers, exhaust and intercoolers
• Custom roll bar system
• Carbonfibre scoop built into stock hood
• Custom-built engine bay, aprons and firewall treatment
• Reshaped front fender angle to align with custom steel bumper
• Custom front-end apron
• Tucked custom stainless-steel front and rear bumpers
• Machined aluminum rear bumper guards and front bumper impact molding
• Custom lower valance with exhaust exits 
• Custom chin spoiler 
• Extended rockers to cover frame rails
• Tubbed rear quarters
• Custom carbonfibre decklid spoiler
• Flush-mount B-pillar side glass
• Full carbonfibre side mirrors
• Integrated nitrogen-powered air-jack system
• Machined door jamb vents
• Custom floors and driveline tunnel
• Custom interior
• Custom billet machined badging

SPONSORS:
Corporate: BASF/Glasurit, Gentex Corporation, HRE Wheels.
Product: California Car Cover, Dynamat, GFS – Global Finishing Solutions, Heat Shield Products, Miller Welding, MSD, Wisconsin Turbo Experts: Dyno tuned by Brigham White and Curt Miller.