Test Pipe?

[Fearit22]

Would it be harmful to my car to use a test pipe for longer than a few runs at the track? I know that having some backpressure on your valvetrain is a good thing, but will running a test pipe all the time greatly decrease my engine life? I already have pacesetter headers and a 2.5" exhaust installed...

[Andrew]

Backpressure = Bad, always
Flow Velocity = Good
Test Pipe = more emissions into atmosphere, no effect on engine life.

I think I read that Pacesetter headers have something like miserably small 1" primaries...