Problem with not running one is that the headers are prone to cracking as they are, let alone running through extreme heat cycles with the weaght of the turbo pushing down. Plus, poorly designed exhaust systems will also weigh down that side. Picture the turbo, downpipe, cat/test pipe, and part of the exhaust weight, all resting on the passenger side manifold. Then cycle it through extreme heat enough to make it glow. You can almost guarantee to be rewarded with a nice, wide crack.