IN DEVELOPMENT - G.I. Boost - RAD Atlas 4200 Turbo Swap Powertrain Solution
IN DEVELOPMENT - G.I. Boost - RAD Atlas 4200 Turbo Swap Powertrain Solution
Starting around $16,499
RAD G.I. Boost - Atlas 4200 Turbo
PSI Hard Series | American-Built 4.2L Inline-Six | Targeting 800+ HP | Engine, ECU, Wiring & Final Tune
In development · Expected in 2027 · Estimated starting price: $16,499
An American straight-six deserves a second look. The 4.2L Atlas brings its own sound and character to a hot rod: smooth in ordinary driving, strong through the midrange, and ready to pull hard when the turbo comes in. Lift the hood and it’s a conversation starter. Put your foot down and it has a point to make.
RAD builds the Atlas as a complete engine-side combination. Forged internals, a forward-facing intake, rear-sump oiling, a single turbo, fueling, ECU, wiring, boost control, and a finished tune are specified together. It gives a builder who wants an American six a defined starting package, with the power and street manners to make the choice rewarding.
- Targeting 800+ advertised engine horsepower
- Targeting mid-600s+ rear-wheel horsepower in street trim, with an air filter, catalytic converters, and mufflers
- Fully blueprinted 4.2L aluminum inline-six with forged pistons and rods
- Rear-sump oil pan, matched pickup, and dipstick included
- Forward-facing intake, fuel rails, and injectors included
- Single turbo, turbo manifold, wastegate, and blow-off valve included
- Flex-fuel capability, closed-loop boost control, and engine-protection strategies
- Includes standalone ECU, engine wiring, completed RAD tune, break-in, and dyno testing
A Different Kind of American Muscle
G.I. Boost's Atlas’s 4.2 liters give this turbo combination a full-bodied response in normal driving and a hard charge when boost builds. RAD is developing it for the trips a street car actually makes, with attention to startup, idle, part-throttle behavior, and boost response alongside full-power operation.
It’s an unusual engine to find in a muscle car or classic truck. That’s part of the appeal.
Fully Blueprinted 4.2L Engine
Each Atlas is disassembled, inspected, measured, machined as required, and assembled with clearances set for the finished turbo combination.
Engine Assembly and Valvetrain
- 4.2L aluminum Atlas inline-six
- Forged pistons, piston rings, and connecting rods
- Upgraded cylinder-head studs and performance head gaskets
- RAD-selected performance camshaft
- New lifters, matched valve springs, and retainers
- New water pump and thermostat
- Measured bearing, piston, ring, and valvetrain clearances
Oiling, Induction, and Turbo Hardware
- Modified rear-sump oil pan, matched pickup, and dipstick
- Forward-facing intake manifold
- Fuel rails and injectors selected for the turbo and flex-fuel combination
- Single turbocharger and turbo exhaust manifold
- Wastegate, blow-off valve, and boost-control hardware
- Startup oil and filter
ECU, Boost Control & Final RAD Tune
The included ECU and engine harness manage the Atlas’s fuel, ignition, variable valve timing, flex-fuel, and boost systems. Fuel-pressure, oil-pressure, and oil-temperature monitoring support the engine-protection strategies. Closed-loop boost control includes the sensing and control hardware needed for the finished combination.
The RAD tune covers startup, normal driving, changing ethanol content, boost response, and full-power operation. Each engine is broken in and dyno tested before delivery.
Throttle-body selection, accessory drive, charge plumbing, exhaust, and vehicle-specific installation parts are configured separately for the build.
Interested in putting an American turbo six to work? Contact RAD about the Atlas 4200 development program.
RAD — Engineered Powertrain Solutions. Ready to Drive.
