Downpipe Install

If you're one of the lucky ones who drive around with a turbo or two huffing exhaust into horsepower with the stomp of a foot, then you already know performance is what puts a smile on your face. More performance is always welcome, especially if it doesn't come at the cost of anything else. As you may well know, a great number of performance upgrades come with a price tag. Payment may be in the form of lost mileage, increased engine wear, overheating or similar loss of drivability, and so on. Payment may also take a big chunk out of your wallet.

One great way to uncork a turbocharged vehicle exhaust is to open it up directly after the turbocharger by way of a downpipe.
While some would argue that speed is just a matter of money, others maintain the best kind of performance upgrades are those that come with little or no mechanical or financial tradeoff. Opening up, or "uncorking" the exhaust is just one of those upgrades—especially if turbocharging is part of the performance equation. One great way to uncork a turbocharged vehicle exhaust is to open it up directly after the turbocharger by way of a downpipe.

Hot Side Huffer
The turbocharger is brilliant in its simplicity. Up to 1/3 of an engine's energy can end up flying out the tailpipe. A turbocharger catches this energy and recycles it back into the engine in the form of more air and fuel. The turbocharger does this by way of a couple of finned wheels. The fins on the wheels are designed to utilize airflow. The hot wheel, or turbine, catches the energy of the exiting exhaust and spins. The cold wheel, or compressor, is connected to the hot wheel by a solid steel shaft and therefore spins at exactly the same rate of speed as the hot wheel. In doing so, the cold wheel compresses air and fuel and forces it into the engine. This causes the engine to make more power. More power creates more exhaust. More exhaust causes the hot wheel to spin faster. When the hot wheel spins faster, so does the cold wheel. The cold wheel spinning faster forces more fuel and air into the engine. This causes the engine to kick out even more power, which produces an even greater quantity of exhaust. And so it goes.


The hot wheel uses the exhaust pressure and velocity in front of it to spin faster. After the exhaust gets past the hot wheel in a turbocharged vehicle, it has no better place to go but away. As a matter of fact, it is extremely important that there is nothing, such as exhaust backpressure, that stops the hot wheel from spinning. The ideal exhaust for a turbo car would therefore be no exhaust at all. While this is all fine and good for the drag strip, it is not at all acceptable to the long arm of the law. Running such an exhaust on the street would most certainly prompt an unwelcome conversation—complete with flashing lights. There is however, a compromise that will hopefully keep everybody smiling.

Legal Compromise
One quick and effective way to improve post hot wheel exhaust flow in a turbocharged vehicle is to bolt up a high flow downpipe in place of the catalytic converter or stock tubing right after the turbo. The downpipe gives the hot wheel exactly what it wants—as much pressure as possible in front of it, and as little as possible behind it. The downpipe mounts directly after the turbo and cleans up the path of the exhaust exiting away from the hot wheel. The faster an exhaust system can get rid of exhaust after the hot wheel the better.