The massive power that the...
The massive power that the twin-turbo 482ci Pontiac makes is readily evident with the nearly uncontrollable burnouts it performed with Rodney Butler at the wheel.
Every year for the two or three weeks preceding the Ames Performance Tri-Power Pontiac Nationals, the hobbyist community message boards buzz with speculation about a variety of racing topics. Everything is discussed, from what the KRE Quick 16 "bump spot" will be, to who has a new combination, to speculation over whether the dollar-a-pound ice cream sales will still be strong.
This past year was no different, but as word started getting around that Rodney Butler and Travis Quillen had been testing their rather mysterious '63 LeMans on an 1/8-mile track in Tennessee, the speculation shifted into overdrive. Would this be the year that the team raised the bar for the entire Pontiac racing community?
It was no secret that Butler and Quillen had been working on the new racecar for over four years, and the amount of research and data collected was staggering. Taking what they learned from Rodney's tube-framed, twin-turbo, gasoline-burning '65 GTO Pro Mod, the team set out not only to build a better all-around machine, but also the quickest and fastest traditional Pontiac-powered racecar ever-doorslammer or otherwise. Add to that the need to be competitive against the current crop of other-make turbocharged Pro Mod racers, some of whom are running well into the 5-second range, and you begin to appreciate the loftiness of their goals. Chassis performance and aerodynamics were as important as the engine itself, because at this level, getting the power to the ground is a much larger challenge than making it in the first place.
The front-end of the original...
The front-end of the original chassis had to be re-engineered, as the twin-turbo 482 was a complex engine to package. A BOP belt-drive system puts the distributor up front, which provides clearance for the unique rear-entry throttle body and inlet plumbing. The 91mm Turbonetic ball-bearing turbos are huge-a significant packaging challenge. They bolt to custom headers, and the Turbonetics wastegates are adjustable and can dial in or out over 1,000 hp. Normal boost settings are 36-40 psi, though they can be changed to accommodate track conditions.
You may remember the engine from our story "High-Tech, Lightweight, and Ready to Take on the World" a few years back in HPP. That article outlined the methanol-burning, twin-turbo, 2,880hp, 482ci, traditional Pontiac V-8. To briefly recap, the engine was based on an aluminum IA II block with 370-cfm wide-port Edelbrock heads with Ferrea special-alloy 2.19/1.77 valves. Aside from a change to an iron IA II block, it's the same engine that was in the article, and is actually quite similar to the single-turbo engine outlined in the final edition of our crate engine series.
The long-block is constructed entirely of off-the-shelf components. This particular engine uses a 4.25-inch Moldex crankshaft and 6.800-inch GRP aluminum rods with 17cc-dish Ross pistons for a compression ratio of 10.0:1. While that might seem like a lot for a turbo combination, it's actually a bit low for one burning methanol.
Both exhaust turbines feature...
Both exhaust turbines feature massive 5-inch outlets, which are routed through the front fenders. The noise this engine makes sounds like machine gun fire.
It's the induction system that separates it from the aforementioned crate engine, though the Butlers will build one of these engines for you as well. The intake manifold is a custom sheetmetal unit designed and built by Travis, and nicknamed "Starship Enterprise" because of its unusual shape. It mounts a single, rear-facing Accu-Fab 90mm throttle body and houses a total of 24 Bosch 160-lb/hr injectors, three per intake runner-one on top and two underneath. They are driven by a Waterman fuel pump that is regulated by a boost-referenced Weldon fuel-pressure regulator set at 70-psi base.
Forced induction is provided by a pair of 91mm Turbonetics ball-bearing turbos rated at 1,600 hp each. Exhaust gases are routed to them by a set of custom-fabricated headers that Travis and Rodney built for the car, with 2-inch primary tubes and 2.5-inch collectors. The turbos expel the spent gases through 5-inch downpipes that exit through the front fenders. Ignition chores are handled by an exotic front-mounted BOP distributor, using an MSD Digital 7 amplifier and HVC coil. They fire the NGK 5671A-10 spark plugs through 8.5mm MSD wires.
The turbos are capable of providing more than 40-psi boost pressure-an astonishing amount that would be impossible without the cooling effect of methanol. In fact, even under such huge boost numbers, intercooling is completely unnecessary, as ice will form on the intake manifold, owing to methanol's incredible heat-absorbing ability.
A FAST XFI unit, programmed and calibrated by Travis, is the engine's control system. It features a convenient laptop interface and data capture, so every revolution of the engine can be logged and analyzed. Over 20 channels of information are recorded, including driveshaft speed, fuel, oil pressure, and air temps throughout the intake tract.