A single 90mm Accufab throttle body controls the airflow. It may sound small, but with 52 pounds of boost pushing things along, it can flow somewhere around 4,000 cfm. The black clamp and weld-on ferrule are Accufab's answer to the more complex and expensive Wiggens clamp previously run.
Dry-sump oiling is a given in the Accufab engine, along with what seems like powerful crankcase vacuum generated by this $2,100 Dailey Engineering dry-sump pump. It's a four-stage pickup pump and features a hex-socket drive, seen here at the far end of the pump. John runs a cable drive from this hex to the rear of the car, where it powers a high-volume mechanical fuel pump. The car is started using a small, electric boost pump, but once lit, the engine is supplied with fuel through the oil pump and cable drive.
As-installed, it's difficult to find the core engine under the air plumbing and wiring. Here the right cam cover--another stock part--plays host to the ignition coil packs. These are now Mercruiser-made Evinrude two-stroke coils, which are even hotter, lighter, and less expensive than their predecessors. Fred, who's gotten across these zappers, says they're "bad ass. [They'll] blow a hole in your arm!" Also seen is a fuel rail and bleed line, along with the tightly packed injectors.
He's run or experimented with various turbo configurations, but large-framed Garretts have proven the most powerful. This is the inlet side as it runs, with no air filter or other tubing other than the hoodscoops which feed directly to the turbo inlet. The large area around the smaller impeller inlet is a ported shroud; it bleeds some air off the impeller and back to the inlet to reduce surging when the blow-through throttle is snapped shut at the end of a run.
Yep, there's a single Accufab throttle body in all this. The stock 90mm unit is mounted behind the radiator on the intake's trunk-like entry.
So far, John's exhaust system has been upswept for packaging concerns. Eventually the heavy turbos will be low-mounted on a down-swept exhaust to improve the center of gravity for improved launch dynamics, but experiments in that direction have not worked so far.
Given up to 60 pounds of exhaust backpressure, tremendous temperatures, and generally hellish conditions all-around, the exhaust system is built of 321 stainless steel. Everything is exceptionally heavy-duty, including the -inch-thick flanges, 2-inch-diameter primary pipes, and Reid Washburn collectors. There's nothing stock, lightweight, or inexpensive here. The small ports are for the Race Pak V300 data acquisition system's EGT probes.
Even the starter motor has an Accufab twist. A Hitachi unit popular with racers, it features an aluminum adapter made by Accufab for Hitachi.
John had to make his own flywheel because none were available that would accept a Crower clutch. The result is this 14-pound CNC'd beauty. Starting life as a square slab of aluminum billet, the flywheel is whittled on the same in-house CNC machines that make the Accufab throttle bodies. The friction plates are segmented to avoid heat warping, and the bearing surfaces are diamond hardened. Accufab doesn't necessarily sell this flywheel, making it just for its own race car and a handful of engine customers.
With the transmission removed and looking forward through the firewall and missing bellhousing, the Crower three-plate clutch is front and center. The blue tubing is a water bypass running from the block to the back of the cylinder heads in support of the dry-deck modification. More mundane is the large, brown breather hose draped across the scene.
A wide-angle lens doesn't distort this detail of the radiator along side the oil tank; huge pressures inside the cooling system have deformed the compact heat exchanger. They're from combustion gas due to constant head gasket leaks from the unreal combustion pressures. Dry-decking the engine was the only way to put an end to this, but the bowed radiator remains.
Crawling on the shop floor and looking up at the right side of the engine compartment shows the Accufab CNC'd oil pan. It's part of a carefully controlled oil environment in the crankcase, plus its thick billet construction must aid block rigidity.