If you are serious about performance, a cat test pipe represents an important part of your exhaust plans. Once installed, a cat test pipe frees up exhaust flow that is usually choked by the factory system. There are consistent gains in horsepower, a noticeable jump in throttle response, and a hungrier back-end tone. That is why Invidia test pipes are used most often by racers and off-road performance enthusiasts.
A good portion of the restriction coming from your exhaust system is caused by the catalytic converter. This is due to the converter's job (filter smelly, harmful exhaust fumes) and the bends of the pipe. Exhaust can't get through as easily, which holds the engine back. A cat test pipe is a straight through answer, demonstrating a wider (60mm) and more concise path for exhaust gases to be distributed out of. The engine of your car isn't as strained, popping out extra horses and torque.
The performance benefit of an Invidia high flow test pipe is noticeable immediately. Throttle response is quicker and the exhaust tone has more of an edge to it. Throttle response is key for racers, who cannot tolerate lag off the line or when the green flag drops. As for the amount of horsepower an Invidia high flow test pipe is good for, that depends on if they have a full racing exhaust or not. By itself, an Invidia high flow test pipe would be responsible for 1-3 HP. But coupled with custom auto exhaust parts, that number could be as high as 7-10 HP. It also matters what year, make, and model the cat delete pipe is installed in.
Invidia test pipes are crafted from SUS304 stainless steel for the entire part (flanges are stainless steel, also). Each pipe is robotically TIG-welded and mandrel-bent to promise accurate bends. The stainless steel finish is both rust and corrosive-resistant, and comes polished for showroom-ready looks.
It should not be necessary to make any other modifications when installing an Invidia test pipe. Installation is a complete bolt-on application and can be used along with your stock exhaust system or downpipe. Invidia test pipes come with stainless steel hardware and a rear gasket.