Howard Tanner of Redline Motorsports has been cranking out high-horsepower builds for nearly two decades. Based out of Southern Florida, and always looking for ways to outdo himself with the next project, it can be pretty exciting to see what he’ll be rolling out with next.
Sometimes it’s a personal build of his own, sometimes, it’s a customer car. In this case, a customer had brought him a street-focused 2020 Camaro ZL1. Already potent with 650hp under the hood from the factory, and then, built by another shop out of Texas, the customer simply wanted to take things to 11. In order to achieve his goals, Howard Tanner himself stepped in and offered his services, and built the engine himself.
Starting with a stock LT4 engine block, the bare aluminum foundation was machined to a 4.070-inch overbore, the block surface was decked for trueness and the main bearing journals were line-honed.
Inside the refreshed engine block, Manley Performance I-beam connecting rods, “Turbo Tuff” forged aluminum pistons, and a 4.00-inch stroke crankshaft helps bump up the displacement an additional 40-cubic inches from the original 376, to a full 416.
Moving up to the top end, LT4 cylinder heads that were cleaned up, and stuffed with Titanium intake valves and Inconnel exhaust valves. The valvetrain has been paired with a Redline Motorsports Phase 4 hydraulic bumpstick. Induction is handled with a 103mm throttle body, feeding oxygen into a Frankenstein Low-Profile Port Fuel billet LT4 intake manifold.
More air is great, but there needs to be a balance. Upping the ante on the fuel side of things, we’ll find a triple in-tank Walbro fuel pumps. customer-made PTFE fuel lines went into the recipe, as did a set of 1000cc fuel injectors to support the planned E85 fuel. The fuel system is managed by a Holley HP Controller to run the port fuel and boost control.
Now, the fun part; the source of the boost. Howard implemented a Huron Speed Twin-Turbo Kit that, paired with a 6-inch thick air-to-air intercooler and a custom-built aluminum inlet tube. After some time on the Mainline Prohub dyno and some ECU tuning, Howard finessed a total of 1,029hp and 892-lb ft of torque at the hub.
Of course, you can’t leave the transmission in its OEM format without fortifying the transmission with some improved internals. To be able to handle the power, torque, and abuse, RPM transmission was called upon to build a Level 6 TR6060 transmission that’s paired with a Monster triple-disc clutch to reliable gear selections.
With such a powerful, well-rounded, and obviously very fast car as the final product, it holds itself as a true example of what is currently possible with the right combination of modern tech, and old school ingenuity.
Rick Seitz is the owner and founder of GMEFI Magazine, and has a true love and passion for all vehicles. When he isn’t tuning, testing, or competing with the brand’s current crop of project vehicles, he’s busy tinkering and planning the next modifications for his own cars.
