A turbo downpipe is the necessary exhaust pipe attached to a turbocharger.
The function of the downpipe is simply to channel the exhaust from the turbocharger to the exhaust pipe. The exhaust in a turbocharged engine travels through the head, into the manifold, along the headers, into the turbo where it spins the turbine, down the downpipe and into the catalytic converter and then out through the exhaust pipe. Sometimes, the catalytic converter is built into the downpipe.
Aftermarket downpipes, often stainless steel, are frequently wider and less restricting than a stock downpipe. A racecar driver with a turbo will look into a wider downpipe because the openness will allow for greater exhaust flow. This will increase the turbo spin, generating more spool, and decrease turbo lag. Also, a wider downpipe can decrease engine compartment and intake charge temperatures, producing denser air and, therefore, greater power in the engine.
HKS Turbochargers, GReddy Turbochargers and Garrett Turbochargers are three reliable turbocharger and turbo downpipe manufacturers who may provide more detailed information about how their specific downpipe products can improve the horsepower on a turbocharged engine. Flowmaster is also a highly recommended supplier for exhaust kits.
