At SEMA 2025, a few vehicles created a stir, like Edelbrock’s Muskrat, a Tesla big-block swap that turned a 2015 Tesla Model S 85D into one of the most outrageous builds at the show. What began as an ordinary electric commuter car has been reborn with a 565 cubic inch twin-turbo big-block Chevy, transforming quiet efficiency into an unapologetically loud and aggressive street machine. Edelbrock engine builder and technician Robert Freund walked us through how the project came together and why the Muskrat has become a favorite at drag-and-drive events.
The EV platform was never part of the final plan. The Tesla was purchased as a wreck to salvage its electronics for a separate project involving a 1968 Mustang. Leaving the Model S shell behind, the Edelbrock team decided to create something entirely unexpected. The body was separated from the crash-damaged factory chassis and mounted onto a complete tube-chassis structure. This approach made the initial build possible, although it created challenges later when servicing major components with the body in place.
A 565ci Twin-Turbo Big-Block With Proven Parts
The heart of this Tesla big-block swap is a 565 cubic-inch Mark IV big-block Chevy, built with readily available components from Edelbrock, COMP Cams, Lunati, and other respected manufacturers. The combination is based on an architecture similar to Edelbrock’s 555 MUSI engine, utilizing a 4.600-inch bore and a 4.500-inch stroke. It runs 10:1 compression and sees 18 to 20 pounds of boost from two HPT 78-millimeter ball-bearing turbos.
Airflow comes from Edelbrock Victor 24-degree MUSI CNC-ported cylinder heads and an Edelbrock Pro Flo XT intake manifold. Inside the block are Lunati Pro Series X Beam connecting rods, a Lunati Signature Series crankshaft, COMP Cams DLC XD Race lifters, and a custom tool steel camshaft. A TCI-built Turbo 400 transmission sends power to the rear wheels, and on E85 fuel, the Muskrat averages about seven miles per gallon.
On the track, the results speak for themselves. The car runs in the mid-eight-second range at about 165 miles per hour. At roughly 4,200 pounds, the power level works out to about 1,500 horsepower, a figure that matches the car’s personality and its purpose.
Built For Drag-And-Drive Mileage
Although the Tesla big-block swap debuted as a street car, it evolved naturally into a drag-and-drive contender. The Edelbrock team recently completed the Sick Smokies event, switching between race mode at the track and street mode during the long highway stretches. The Muskrat tows a full support trailer that carries tools, tires, quick jacks, and fuel. Since the car runs exclusively on E85 and pump availability varies, it carries a 28-gallon tank in the chassis and an additional 75 gallons in the trailer. Depending on the route and terrain, the team sometimes needs a 500- to 600-mile range before the next opportunity to refuel.
The wide Tesla cabin became one of the unexpected advantages. Freund explained that the extra interior space makes long-distance trips easier, especially for larger drivers. The race seats were reupholstered with added padding, and many factory conveniences remain, including electric windows, door functions, mirrors, and key fob operation.
A Trailer Built Like A Rolling Pit Space
The trailer itself is a major part of the program. It uses Tesla’s original rear brakes in an electric-over-hydraulic system controlled wirelessly through a phone app. Inside are Milwaukee Packout drawers, hand tools, spare parts, and a complete fuel transfer system that fills the car through quick disconnects. The team keeps components that cannot be sourced easily on the road, including a spare fuel pump, coil packs, plug wires, and hardware.
Looking Ahead To 2026
Edelbrock plans to update the Tesla big-block swap with a new 540 cubic inch engine built by Advanced Racing Engines using a Brodix aluminum block. The goal is to lean harder on boost while reducing overall weight. The team is registered for Sick Week 2026 and expects the next version of the Muskrat to be even more capable.
For many attendees at SEMA 2025, the Muskrat served as a reminder that creativity still fuels the performance world. When a Tesla gets a big-block, subtlety disappears, and attitude takes its place.
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