Turbocharged vehicles that come straight from the factory often suffer from
restrictive downpipes, mainly to ensure that they pass emissions.  This creates a
bottleneck for performance seeking enthusiasts.  Turbos need to be able to expel
gases as fast as possible with little to no backpressure.  Sometimes, a downpipe
or up-pipe is the best bang for the buck when it comes to performance besides a
performance chip or ECU.  Please note that some downpipes/uppipes do not utilize
a catalytic converter which may not be legal on U.S. Highways, for offroad
purposes only.  Check local laws before purchasing.