MAXIMIZING EFFICIENCY

While the previous engine used a HeadGames hand-ported cylinder head, Shep had a buyer for his previous engine and turbo setup. This provided an opportunity for Shep to employ a set of the AMS Alpha CNC Race Ported Cylinder Heads. These heads are CNC ported which allows each port to be matched in flow to each other. Tool marks from the CNC process are smoothed over by hand. The heads includes a complete Ferrea Competition Plus valvetrain featuring +1mm oversized valves, high-rate single valve springs and titanium retainers. According to AMS Performance, these heads provide an 11-percent increase in average intake flow with a peak intake flow increase of nearly 20 percent. On the exhaust side, flow is improved to the tune of a 20-percent increase in average flow with a 27-percent increase in peak flow.

A set of AMS Performance by Kelford Cams Alpha camshafts orchestrate the valve events. By increasing the flow capabilities of the cylinder heads through porting and proper camshaft selection, improved cylinder filling can result. This allows more air/fuel charge to be forced into the cylinders during the intake stroke while also allowing the residual cylinder pressures after combustion to be exhausted faster on the exhaust stroke (reducing the power wasted by pumping the exhaust out of the cylinder). The end result is an engine that maximizes power for each pound of boost pressure in the manifold. Best of all, the combinations delivers a nearstock idle at 800 RPM with a 14-to-1 air/fuel ratio.

BIG BOOSTING

When the time came to select a turbocharger system, Shep opted for the Alpha 12 Turbo Kit from AMS Performance. This system uses a 1.5-inch diameter, equal-length, tubular cast stainless-steel exhaust manifold that delivers crack-free performance while positioning the Alpha 12 billetcompressor turbochargers in place. AMS Performance claims that 1,250whp can be realized on a 4.0-liter VR38 on race gas or E85 with its Alpha 12 system. Based on the trap speed and weight of Shep’s R35, wheel horsepower is just over 1,300 or over 1,500 at the flywheel.

FUEL AND CONTROL

[pullquote]PROVIDING ENOUGH E85 TO PRODUCE 1,500 HORSEPOWER IS NO EASY TASK [/pullquote]Providing enough E85 to produce 1,500 horsepower is no easy task. Switzer Performance fitted its triple-pump solution in the factory tank. From the tank, a pair of -6AN lines feeds the primary rails that hold a six pack of Injector Dynamics’ ID1000 fuel injectors. The factory intake manifold was modified by Switzer Performance to house an additional half-dozen ID2000 injectors. All 12 injectors and the factory ignition coils now take direction from the Syvecs S8 engine management system. This stand-alone solution not only delivers the ability to control 12 injectors, but also provides for Flex-fuel management. Switzer Performance provided the Syvecs S8 with the base mapping. After inital tuning on the Switzer Performance DynoJet, Boyan from Switzer Performance later fine tuned the vehicle at the strip.