Arin@APR
GOLFMK7 Official Sponsor
How is casting cheaper than buying and bending a pipe? I personally don't see a performance benefit to it. Certainly will be more reliable at the flange, especially for cars that see snow and salt, may sound better. But it sure as hell isn't cheaper than a buying a pipe.
There are several benefits to it mentioned above, most notably is the turbo outlet port matching and organic shape.
Someone asked how this system compared to our old one. Here are the improvements we made:
The new system was fully designed and developed in-house with final assembly taking place here at APR. The previous systems were private labeled through another vendor. We made the switch when we built up the necessary infrastructure to do it on our own. The assembly and quality control is also in house, allowing us to have a higher level of confidence in the final product being as advertised.
We’ve upgraded all of the components to a higher quality T304L stainless steel from the 439 and 304 used on the previous system which does wonders for corrosion resistance. We’ve also upgraded the welding to argon back-purged TIG welding where as the old system was MIG welded.
The most obvious difference is the use of an investment cast inlet and outlet. The inlet is port matched to the turbo, which comes in at 80mm, and gradually necks down to the 76mm pipe’s ID over a long distance. This reduces back pressure and turbulence through the high flow, organic shape. The old system sharply necked down directly out of the turbo. Furthermore since the new system is cast, there’s no welding at the turbo inlet/flange or o2 sensor like the old system, which not only makes the system stronger, but further reduces turbulence.
We’ve bumped up the quality of the flex section as well. The low profile and corrugated is less likely to rub, fray and fail over time compared to the old unit we used.
The bracket is weldless, reducing more chances for failure, and thicker, thus reducing deformation, compared to the stamped piece used before. There’s also more room for adjustability between different vehicles.
The clamps were upgraded to an OEM style slip clamp that doesn’t rely on deforming the pipe to make a tight connection like the old style clamp. It’s easy to install, easy to remove, and allows the pipes to butt right up to each other, because there’s no swedging, reducing turbulence. This also allows for better compatibility between systems since it’s just a straight pipe.
The oxygen sensor bungs are actually cast and welded to the outside of the pipe, which prevents the bung from protruding into the pipe, causing more turbulence like the ones used on the old system.
The piping quality was raised as well. We’re now brushing the exterior to give it a nice finish compared to the raw finish on the old system. The pipe has excellent roundness and a very good interior weld seam which overall makes it a higher quality tube above the obvious material change. The pipe is also designed to perfectly match the OEM catback, so no cutting is involved like on the old system.
The catalyst was upgraded to a high quality GESI unit. The GESI unit is larger and as such, less likely to impede airflow compared to smaller units with less surface area. The catalyst is brazed to the substrate and encapsulated, so unlike the old system, it’s less likely to fail and cause a blockage in the system. The cell count was raised meaning lower emissions, and was done so without restricting flow.
Finally the reducer is a 1 piece design vs the 2 piece MIG welded unit we previously used.