This part is only necessary if an APR Stage III/III+ Turbocharger System was purchased and the vehicle does not have an APR downpipe. The kit includes a midpipe with catalyst, reducer, o2 harness and clamps. The turbocharger systems include the necessary components to connect the midpipe to the turbo.
The APR Downpipe Exhaust System features premium grade T304L stainless steel for its excellent appearance, strength and corrosion resistance properties. The pipe is rolled to the 76mm European standard diameter with a 1.5mm wall thickness and a seemingly non-existent weld seam.
Pipe is cut to length in-house via APR's CNC-controlled bandsaw to an accuracy of .25mm, ensuring a precise fit. Each pipe is de-burred, and the exterior finish is brushed to give the exhaust piping a clean and attractive appearance worthy of the APR name. APR’s fabrication team uses argon back-purging during the welding process, leaving a clean and smooth interior surface, and TIG welding for strength and appearance. Lastly, no swedging or slip-fitting is necessary due to APR’s OEM-style clamp design, leaving smooth and less turbulent connection points.
APR’s engineers specified a T304L stainless steel, OEM-style exhaust clamp designed to eliminate the need for flanges, swedging, or slip fittings. By using this low profile design, the exhaust system can be positioned higher in the exhaust tunnel and away from the ground with better clearances compared to flanged setups. Each clamp allows for less turbulence and greater accuracy at the connection points as the pipes simply butt up to one another rather than the ambiguity and voids associated with swedged slip fittings. Furthermore, the clamp doesn’t rely on deforming the pipe to provide a tight seal, making install and removal more convenient.
A simple and removable, T304L stainless steel reducer, featuring a smooth transition, is included, making the APR Cast Downpipe Exhaust System directly compatible with the OEM catback exhaust system. Both 1.8T and 2.0T reducers are included with each system.
A high quality oxygen sensor extension harness is included as the catalyst and sensor bung is relocated further away from the turbocharger.
APR is pleased to present the ultimate Cast Downpipe Exhaust System!
Upgrading the restrictive factory downpipe with the APR Cast Downpipe Exhaust System is a great way to increase performance and add a sophisticated growl to the exhaust note. Ideal performance is achieved through expelling exhaust gasses at maximum velocity through APR’s proprietary, low-turbulence, investment cast downpipe. Designed and assembled in-house, the system utilizes only premium materials and world-class manufacturing techniques to deliver unmatched quality and reliability.
The factory downpipe system consists of smaller, 63mm piping with varying bends and multiple restrictive high-cell-count catalysts, all of which contribute to a less than ideal flow path and hindered performance. APR’s engineers took a multi-step approach to maximizing flow, reducing under hood temperature, and eliminating unnecessary restrictions all in a unique package only APR can deliver.
The APR Cast Downpipe Exhaust System is a complex system designed to deliver maximum performance. Each component was designed and developed with the absolute best in performance, strength, reliability and quality in mind.
Select the images below to view detailed photos and information related to each component.
The exhaust system features a strong, investment cast, T304L inlet and outlet designed to maximize flow and minimize turbulence. By casting the inlet, APR’s engineers were able to create a smooth and high-flow exhaust path that maximized flow through swept blends and shapes that are otherwise not possible through conventional fabrication techniques. The inlet perfectly matches the factory turbocharger’s 77mm outlet and gradually necks down over a long distance to further enhance performance. The mounting flange and bracket are integrated into the casting, and TIG welding at the flex section ensures a clean inner surface eliminating turbulence, vortices and eddies to the highest degree.
With a nominal wall thickness of 2.55mm the downpipe is strong and produces a refined exhaust note compared to thin wall tubing systems. The cast sections undergo a tumbling process to smooth and de-burr any imperfections inside the pipe, while simultaneously enhancing the exterior finish. Lastly, all necessary surfaces are CNC machined for an accurate fit.
Reported wheel figures measured on APR's in house Dynapack Dynamometer with a 2014 MK7 Golf Tiptronic and 2014 MK7 GTI DSG, using SAEJ1349 correction and an average of multiple runs. Crank figures estimated based on the measured wheel figures. Results will vary depending upon environmental conditions, vehicle, transmission, vehicle health, operating conditions, temperatures, fuel grade, dyno type, dyno setup, and other modifications.
In the past APR worked with other manufacturers to develop a limited range of private-label exhaust systems outside the scope of APR’s internal development and manufacturing capabilities. Understanding the limits of such a program, combined with APR’s desire to deliver higher-quality products in a timely manner with better customer support, APR invested in internalizing the program. With the release of this exhaust system and the others like it, APR is pleased to present our first systems fully designed and engineered in-house from the ground up!
Design and development begins with the use of APR’s professional grade in-house coordinate measuring machines. APR’s engineers have full access to a Romer Absolute arm with integrated laser scanner, FaroArm and Creaform 3D laser scanner for collection of special constraints surrounding the factory exhaust system. The engineers scan the vehicles and create detailed 3D maps of their design environment while designing each system in PTC Creo 3.0 CAD software.
Using APR’s in-house stereolithography 3D printer, rapid prototypes are created for fitment on the vehicle. The design is easily and quickly verified, and if necessary, changes can be made. Once adequate clearances and fitment is confirmed, especially in areas that move under load, physical quick-cast prototypes are created and fitted for final verification through real-world use.
APR’s world-class manufacturing partners from around the globe are responsible for manufacturing each component that falls outside of APR’s internal capabilities. Working closely with each manufacturer, APR’s engineers supply CAD models, materials specs, and other design specifications and work hand-in-hand with the manufacturer to develop the components. The end result is a collection of components, wholly unique to the APR name, awaiting final finishing, assembly and quality control at APR’s 78,000 square foot facility in Opelika, Alabama in the USA.
Manufacturing takes place both internally and externally to APR while finishing and assembly is completed in-house. APR’s fabrication team cuts, brushes and de-burrs premium grade T304L stainless steel piping for use in each midpipe. Then each cast component is sent through the ceramic vibrating tumblers to smooth and de-burr surface imperfections. Each component is then cleaned by hand and prepared for assembly.
APR’s fabrication experts TIG weld each component, creating reliable, high quality and attractive welds. Each component is back-purged with argon during the process ensuring the weld is strong and consistent, as well as clean throughout. With this process complete, the APR Cast Downpipe Exhaust System is born!
APR has placed a large emphasis on improving quality control across various product lines, and the exhaust program is not excluded. To ensure the systems are delivered as advertised, APR’s engineers have taken a multi-step approach that encompasses many techniques that go beyond the industry standard.
APR’s engineers request full metallurgy reports with each batch of components to ensure the components are made with the T304L stainless steel grades specified on the original design prints. This information is then cross-referenced against randomly selected and independently tested samples before the components are released for assembly.
Great designs only matter if the manufacturer delivers the components as expected. To help ensure the designs are as specified, APR’s engineers randomly select components and conduct full dimensional inspections using in-house 3D laser scanning equipment. Tolerances are digitally checked against the original specifications and passed or failed based on the results.
Operating in an environment designed for accuracy and repeatability, APR’s fabrication experts leave little room for error during the final assembly phase. Jigs and fixtures, created in-house, live on custom-specified fabrication tables featuring repeatable indexing holes and extremely flat surfaces. This working environment ensures the highest level of quality control during the assembly process and safeguards against dimensional variations potentially created during the manufacturing process. The end result is a system that fits every time as it’s true to the original design specifications.
When hand-building the products in-house, an extra level of control takes place. Components are visually checked for imperfections, and items that fall out of quality standards are rejected. The products are then packaged with care before being distributed across the world.
APR’s confidence in the system’s quality allows for a limited lifetime warranty.