Brad Johnson's Pontiac Firebird Formula 400: A Story of Power and Evolution
In the world of street machines, few stories are as captivating as Brad Johnson's journey with his 1974 Pontiac Firebird Formula 400. This car, which began its life with a stock 350ci Pontiac engine, has undergone a remarkable transformation over the years, evolving into a powerful beast that commands attention on the streets and at the track.
A Journey Begins
Nine years ago, Brad embarked on an adventure, flying to Rockhampton and bringing this classic Firebird to the Gold Coast. It was a simple setup, featuring a 350ci Pontiac engine, TH400 transmission, and 10-bolt differential. While it was fun cruising the streets, it lacked the punch to truly stand out.
The Pursuit of Power
Johnson, like many enthusiasts, was drawn to the challenge of chasing more power. He decided to swap the 350 for a period-correct 400ci Pontiac engine, a bold move that set the stage for further enhancements. But the real game-changer came when he opted for an LS engine, a decision that would take his Firebird to new heights.
LS Engine Upgrade
The LS engine in question is a built-for-boost 370ci LY6 cast truck block, a powerhouse that receives a boost of performance with a Callies crankshaft, Wiseco BoostLine rods, CP pistons, and MLS head gaskets. The brain behind this engine is a Brian Tooley turbo camshaft, and the cherry on top are Tremaniac CNC LS3 cylinder heads.
A Complete Makeover
To match the new engine's capabilities, Johnson and his team had to build the entire car from the ground up. They sourced an FTI Stage 4 TH400 transmission with a transbrake from Summit Racing, ensuring smooth and powerful gear changes. A matching 9-inch billet converter further enhanced the car's performance.
Under the Hood and Beyond
The car's drivetrain is a work of art, featuring a braced 35-spline housing, a Strange billet HD Pro center, and a Truetrac differential. The gear ratio is a 3.5:1, providing the perfect balance of speed and torque. Stopping power is provided by 11-inch disc brakes, ensuring control and precision.
Rolling Style
Outlaw Drag Intensity wheels, measuring 17x4.5 inches in the front and 15x10 inches at the rear, give the Firebird a sleek and aggressive look. These wheels are wrapped in Nankang rubber, with 165/75R17 tires up front and 275/60R15 in the rear, providing the grip needed for high-performance driving.
Performance Numbers
During its first outing to Cleveland Dyno, the Firebird showcased its potential. With Scott Hoffman's expertise, the car produced an impressive 660hp on pump 98 octane fuel. When fueled with E85 ethanol, the power skyrocketed to 801hp, demonstrating the car's incredible potential.
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