The VAG 1.8T has quickly proven itself as one of the most technological power plants available. While the engineers who developed the kit made fantastic gains in both efficiency and reliability, they left much to be desired with regard to power. The B6 A4 Stage III+ Turbo kit bridges this gap with uncompromising quality and extreme power. Stage III+ is the newest addition to APR's quality line of products for the A4.

While other companies use the terms "tuner" and "R&D" loosely, we at APR feel that quality products start with quality planning. We begin with an idea and study the feasibility of the product. As designers we put a strong emphasis on safety and reliability. APR engineers developed the Stage III+ kit using Pro Engineer Wildfire 3-D CAD software and a Faro Platinum CMM machine. Prototypes are then processed using the 3-D Systems SLA machine. This rapid prototyping procedure allows for quick cast prototypes to ensure a perfect fitting final component. After the component has been verified correct, the final material cast can be run.

The Stage III+ utilizes one of the newest and most efficient turbos available. The Honeywell/Garrett turbos utilize the latest ball bearing design coupled with an integral wastegate and Inconel wheel. Make no mistake, these are not standard turbos retrofitted to ball bearing specs; they are the same type used in countless forms of motor racing such as the Audi R8 in the 24 Hours of Le Mans Series. APR is one of a few Garrett Engineering Houses in the US. We work closely with their engineers to design turbos that produce our desired performance level for each kit.

The APR Exhaust manifold is investment cast Inconel 625. Such material was chosen for its excellent thermal properties. Inconel can withstand temperatures of up to 2500 degrees Fahrenheit without structural degradation. The manifold runners are paired so that the exhaust pulses do not interfere with each other. This design maximizes low-end spool-up and boost-response. The manifold runners were also sized according to the power levels desired and with the size of the exhaust ports in mind. In order to prove the design, the drawing, as it existed in Pro-E, was run through a computational fluid dynamics program. This APR exhaust manifold is arguably the best 1.8T manifold available anywhere in the world due to its superior design and construction. No other company in North America has come close to reproducing a manifold at this level.

Other components quickly reached their operational limits and were also fabricated. The increased flow necessitated a larger MAF Housing. The diameter of the intake tubing was also increased to accommodate the increased airflow. A new larger air horn was placed on the MAF to further increase velocity. A flow straightener was then added to keep turbulence to a minimum. A flow straightener seems like a small detail and is easily over looked by most companies. However, this "small detail" is an integral component of this system allowing the larger MAF housing to be properly utilized. Larger injectors are added to the kit to keep the fuel system within acceptable parameters.

APR engineers write their own proprietary data logging software and analysis programs. This tuning software, combined with APR's Dynapack chassis dynamometer, allows a degree of precision never before seen in the aftermarket industry. Our dyno tuning allows us to tune to any RPM at any load level. This equates into the smoothest, most powerful tuning available. Our software, as with our hardware, is equally ahead of the competition. It's a rare combination to find a tuning company that engineers both the software AND the hardware for their systems. The advantage of designing hardware that is built to utilize our specific software, is obvious. OUR hardware working with OUR software is what comprises a truly engineered "system" and not just a conglomeration of parts.

No other company has the switching capabilities or the programming capabilities that we have. From home programming to industry leading EMCS, our products set the bar in which all others are measured.