The AAM Competition 3.5” (90mm) Resonated High Flow Catted Midpipe for the Nissan GT-R is handcrafted and TIG Welded in the USA at AAM Competition’s facility from the highest quality T304 16-gauge stainless steel. The high flow catalytic converters are made in the USA and feature full metallic 200 cell count cores wrapped in stainless steel. Precision T304 Stainless Steel flanges are laser cut in the USA, and planed after construction to ensure a perfect, leak free exhaust seal. From a design standpoint, the objective is clear – significantly increase performance, have the least possible drone, and stay emissions friendly. The AAM Competition Resonated High Flow Catted Midpipe is engineered for maximum flow while keeping the GT-R’s dreaded exhaust drone to a minimum. The result is a noticeable power gain across the entire rpm range as well as the ability to support additional peak power. Not only will the AAM Competition Resonated High Flow Catted Midpipe allow you to max out the power potential of your stock and aftermarket turbochargers, they are also emissions friendly. This means reduced exhaust gas smell and unwanted exhaust smoke. Additionally, weighing in at only 22 lbs, the AAM Competition GT-R Resonated High Flow Catted Midpipe trims 8 lbs of weight from the factory midpipe! And with OEM fitment, it easily bolts-up to the factory downpipes and rear exhaust as well as most aftermarket downpipes and exhausts. The benefits are clear: The AAM Competition Resonated High Flow Catted Midpipe is the only choice for high horsepower GT-R’s looking to stay emissions friendly while reducing the maximum amount of drone. note: The standard AAM Competition Resonated High Flow Catted Midpipe support up to 900hp. The GESI HFC option is only necessary for GT-R's making in excess of 1000 hp or Nissan GT-R's that see constant track racing (car is used primarily to only race).