Gary Spooner's 454 Twin Turbo Convertible
Trans Am
ENGINE: 1976 2 bolt 454 converted to 4 bolt. aligned bored and Rockwell tested
as well as sonic tested. Forged GM crank, Manley aluminum rods (stock length),
supercharger 7.5.1 pistons, balanced, torque plates installed (Sun machine) roller
timing chain, competition cam Weiand intake 8013, solid mount engine mounts.
OIL: Melling's oil pump. 9 quart oil pan, oil cooler, and custom made remote filter housing. HEADS: 1976 454 120cc chamber heads, Competition Cams pushrods, valve springs, retainers and locks, roller rockers, bronze valve guides, stainless one piece valves intake: 2.20 exhaust: 1.90. COOLANT: Brassworks water pump, Robertson 180 degree thermostat, custom made 6 core rad. (8 inches thick, and fits inside rad support) TURBO SYSTEM: Designed by RPM Research (Gary Spooner). Designed pressure housing, turbo mounting, exhaust manifolds, and all related plumbing. Turbo's are extensively modified by RPM. Turbos are not solidly mounted to exhaust manifold, they are secured at the front of engine. Mounting brackets are designed to allow movement of turbo during heating and cooling (no cracks.) Pressure box completely encloses the carb, therefore few mods to carb throttle plate were required. PRESSURE BOX: 0.060 aluminum, designed by RPM. I wanted to have the carb completely enclosed but still accessible for servicing. TURBOS: TB03 .60 turbine housings and .80 compressor housings respectively, external wastegate (rotomaster) heat shields. Turbo's were previously used as draw-through turbos for the 4.9 litre. I converted them for the blow through method. ENGINE AND TRANSMISSION MONITORING: Designed by RPM, digital computer
technology, non transistor (3 logic circuits for turbo cool down sequence) all relays,
triple pole double throw. Each relay has 2 functions: TRANSMISSION: 1983 700R4 built by RPM. Complete upgrade performed, 9 disc 3-4 clutch, revised overdrive planetary etc, Tony Rossi, Gray Thunder series 12 inch torque converter, turbine and impeller blades heli brazed, angled to give a stock stall speed, double torington bearings at thrust surfaces 2-4 piston replaced with Corvette parts, anti downshift kit for extreme speeds, deep sump pan. TCI flexplate etc. etc. REAR AXLE: Stock GM 81/2 3.08 axle (nice job GM) 4 wheel disc, metallic pads. SUSPENSION: WS6 suspension, urethane bushings, all round, ladder bars, big block springs, 5 leaf thickness rear springs, 50 series on back, 60 on front. INTERIOR: New carpet, manufactured the console, 6 point harness, new ragtop, Fuel pressure (autometer) Vacuum boost gauge (autometer) EGT gauge, controls for computer. Stock gauges. I wanted this car to go in excess of 180 mph. I know it could go in excess of that
speed easily. The rate of acceleration is awesome for a car that is 4200lbs (after mods
completed). The exhaust is quite and the engine runs very smooth. In overdrive at highway
speed of 60 mph engine will generate 20 inches of vacuum. Boost is adjustable, min. 3 psi
to 15 psi. For normal play I run 8 psi on supreme gas, 4 psi on regular. |