Hey Peeps im new on this site i own a (1995 Z28 A4 pretty stock right now) and actually its locked away right now till i can rebuild the Engine and Tranny its leaking oil probably from a blown head gasket and antifreeze probably from the heater core which is what iv'e been told the car has 142,+Miles on her so i gotta do the rebuild of the Trans and Engine but i wanna get this car to lay down atleast 350rwhp and equal or more torque so im gonna do the repairs and then focus on performance this car is also my daily driver but how is the exaust stock/factory is it the 3inch or 2.5 or 2-seperate exaust manifolds or a single exaust manifold? what and iv'e seen a 93-97 Z28 with True Dual iv'e been told that a 3Inch singles it better than why not go with a 3Inch True Dual?

 

A V8 has to have two exhaust manifolds... one for the left bank and one for the right bank. Stock exhaust uses a "Y" pipe to join the outlets of the two manifolds together. Your 95 left the factory with a single cat (unless it is a CA emissions A4 - RPO code YF5 - they use a dual cat setup). The cat is welded to the end of the "Y" pipe, after the two branches come together. Its under the big, ugly hump in the passenger footwell. From there on back, there is a 2.75" intermediate pipe, up over the passenger side of the rear axle, then a single 2.5" inlet cross-flow muffler, with an outlet on each side, giving the appearance of duals.

Popular first upgrade is a full 3" catback. After that, you need to switch to headers, deciding whether you want short- mid- or long-tube headers. Then the question is whether you want to opt for a large capacity cat-back (they make them up to 4") or true duals, with or without an "X" pipe or an "H" pipe.