When installing an Invidia high flow downpipe, drivers know they are taking a crucial step in setting up a complete race exhaust. Whether you are running an aftermarket exhaust or staying with the stock, using an Invidia high flow downpipe means you are interested in kicking performance up a few notches. Sticky, dirty fumes run through car exhaust pipes and are detoured in numerous directions inside of narrow tubing. With an Invidia high flow downpipe, you are able to release the disrupting airflow to give your system added breathability for more horsepower.
The first trait that makes an Invidia high flow downpipe valuable is its diameter. With 3 inches of space available, exhaust fumes have more room to travel. Sports cat down pipes also demonstrate a straight path in place of the factory catalytic converter. Being that the use of a sports cat down pipe replaces your catalytic converter, you have two options. There are catless pipes, which simply substitute the OEM cat to provide increased airflow. Or you can choose a catted pipe to simulate the job of the original converter. Catted Invidia pipes do have a catalyst to filter exhaust fumes, but they are not considered a legal emissions-control device.
At one end of an Invidia turbo downpipe is a 4" bell mouth. This large opening greatly increases the volume of exhaust flow, especially when compared to a stock pipe. What makes the bell mouth capable of functioning at a high level is the overall construction of the Invidia turbo downpipe. Manufactured entirely of SUS304 stainless steel, once bolted in place the pipe will maintain diameter integrity and not crimp or taper. A thinner type of material such as aluminum would bend if designed with the same intention. This feature is what makes an Invidia turbo downpipe preferred by most tuners and competitive racers alike.
You will see a significant increase in horsepower once your sports cat down pipe is installed. There is not one concrete answer as to how much horsepower an Invidia turbo pipe is responsible for. Different dynamometer tests conducted on several sample vehicles have concluded that the approximate number(s) can be as high as 21 HP and as low as 14 HP. But the numbers vary because they do not take into account other performance automotive parts that the cars tested may have had pre-installed.