Evolution Racewerks B7 A4 2.0T Test Pipe

The K03/K04 turbine (exhaust) outlet is almost 3" in diameter. That is why our test pipe features a 3" design that reduces to 2.5" (to bolt up to OEM and most aftermarket downpipe/exhaust systems). Also, we use a "flare" type reducer to reduce the size to 2.5" instead of the "step" type reducer (the "flare" type cost us more to manufacture though). The advantages of the "flare" reducer is that it has a nice smooth transition which causes less turbulence than the step type reducer, therefore producing more power. Also, having the transition as far as possible to the turbo improves performance as well.

The Evolution Racewerks Test Pipe's 3" to 2.5" design is superior over other test pipes that are 2.5" in diameter from inlet to outlet because the 2.5" test pipes will have a "step" right at the outlet. Since the OEM K03/K04 turbos have a turbine (exhaust) outlet of almost 3", the flange of the 2.5" test pipes will actually make a "step" right at the turbo outlet. This step acts like a wall against exhaust flow and when the exhaust hits it, major exhaust turbulence is created, at the worst spot possible, right at the outlet of the turbo. If you have a 2.5" test pipe, check it out. Look at the inlet flange and you will see a "ring" of carbon deposits on the flange. This is the "step" that the exhaust flow is hitting.

The Evolution Racewerks Test Pipe is completely constructed from quality 304 stainless steel and is polished to a mirror finish.  The pipe, flanges, o2 sensor bungs EVERYTHING is 304 stainless steel, even the welding rod we use.  The piping is fully mandrel bent.  Our test pipes are 100% TIG welded for quality and strength.  The flanges are welded inside and outside to the pipe for added strength and extra longevity.

True to ER standards that our current customers enjoy, EVERYTHING needed for installation is including the downpipe inlet gasket.  EVERY bolt, nut and washer that is on the catalystic converter/test pipe is replaced with high quality full stainless steel bolts, nuts, and washers!  Yes that's right FULL stainless steel, down to even the hardware.  The gaskets and full stainless steel hardware alone is worth $50! 

CAUTION: This product is intended for OFF ROAD USE ONLY. Use of this product upon public highways is prohibited.