The stage 3 exhaust manifold is investment cast out of Inconel, a high-temperature nickel alloy. The manifold was designed in CAD and optimized using computational fluid dynamics (CFD) software. What this means to the end user is the ultimate in performance and reliability.

These CAD designed pieces will give the casual observer the impression that the Stage III system was factory installed. The two black powder coated aluminum parts mate with a well placed O-ring and are bolted into the car with top-notch hardware. The inlet pieces are intentionally large and sport smooth lines so as to provide free breathing to the turbocharger.

After the spent gases have left the turbocharger turbine, they flow into this stainless steel piece that directs the exhaust gases down, towards the underside of the car into the exhaust downpipe.

The mass air flow sensor (or MAF sensor) measures the amount of incoming air and sends an analog signal to the engine computer representing the amount of air flowing into the engine. The MAF sensor is mounted in a cylindrical housing that is sized according to engine displacement and maximum power output. We replace the stock MAF housing with a cast aluminum unit to allow the proper metering of the additional airflow and to minimize pressure losses. The cast aluminum housing is CNC machined to exacting tolerances and powder-coated to inhibit corrosion.

A spun aluminum air horn is supplied with the stage 3 system. This component mates to the MAF housing and helps to smoothly collect the air as it exits the airbox.

Representing the latest in turbocharger technology, a Garrett Ballistic series turbocharger is the only choice for a premium turbocharger system. APR is unique in that we deal directly with Garrett turbochargers rather than buying turbochargers through turbocharger supply houses. Our engineering-house distributor status with Garrett turbochargers means that we receive assistance from the manufacturer on technical issues and work with Garrett engineers on specifying the optimal turbocharger for each application.

A custom heat shield is included with the kit to reduce the effect of radiant heat from the exhaust manifold being absorbed into the intake stream.

The correct flow straightener was sourced to ensure laminar air flow through the mass air flow sensor. This is important for proper air flow metering at all flow levels. The flow straightener is sandwiched between the MAF meter and the air horn and is held in place by a retaining clip.