Upgrading the exhaust system is what an Invidia test pipe is all about. If your goal is a complete racing exhaust setup, your car is incomplete without one. What an Invidia test pipe offers is another notch in exhaust liberation that assists in creating a higher level of performance. This improvement in performance is not singularly about more horsepower, but it also involves sporting overall riding efficiency while promoting a pronounced exhaust tone.
What an Invidia test pipe is designed for is to encourage a higher amount of exhaust flow in order to gain more power. Stock exhaust systems work well when it comes to filtering out dirty exhaust gases, but the issue is with their material and construction. Often, an OEM exhaust is comprised of aluminum or cast iron tubing that portrays a narrow pathway with different angles and bends. The catalytic converter, which works to filter the fumes, adds to the level of restraint that keeps your engine from operating at full capacity. An Invidia test pipe takes the place of the cat, offering a direct approach for exhaust to flow with a wider diameter path for gases to exit.
Cat removal pipes come in several sizes in diameter. For most vehicles, there are 60mm diameter aftermarket pipes, but for some they can go as high as 70mm and as low as 50mm. The key point is to present more width than the factory pipes. A big difference is also seen within the material of a cat removal pipe. Invidia uses stainless steel not only for durability, but also to manage the temperature. Steel exhaust parts are better equipped to handle the constant heat that comes from the area in the undercarriage and are deterrent to rusting or corrosion.
On its own, a turbo test pipe can contribute an additional few ticks in horsepower (3-7 HP) and help your turbo spool quicker. But there is a bigger difference if a cat removal pipe is used with other aftermarket exhaust parts. If combined with a full performance system, Invidia turbo test pipes can engage 15-20 more HP.
You see turbo test pipes on display most often in racecars because they are considered an off-road car part. That is because removing the catalytic converter is not allowed under certain state emissions guidelines. You can still use one, but it is recommended to only do so when driving your car on closed courses or racetracks.