putting back a CAT will defeat its purpose or not?
i suggest getting a better muffler (if can, same size as stock muffler), then add bullet to subdue d sound.
when i 1st saw ur muffler, i know its goin to be loud. just too small for V6 engine. not enough backpressure. thats why u lose low-rpm torque.
Back-pressure has nothing to do with it. As I have stated many times...
ALL back-pressure is bad and restricts flow...and it is
flow that provides power.
The way the Y-Pipe works is this :
a) Each ignition, followed by expulsion of exhaust gasses becomes a pressure wave in the piping of the exhaust. The smoother the exhaust flow, the faster the pressure wave, and the more defined the wave form. In other words, a smooth pipe dissipates the wave slower than a rough pipe.
b) Imagine when your engine is on...you get a series of continuous wave fronts pulsing through the piping. Each wave will produce a partial vacuum behind it...pulling the wave behind it. Once this series of wave fronts are stable...you will get a suction effect through the engine thereby pulling more air in the other end of the engine....therefore, more O2 and more power.
c) This system requires pressure pulses and a continuous series of wave fronts to work. At the low end of the power band, when you first start up, it takes time for the pressure waves in the piping to build up. Before this build-up, the pressure waves produced tend to dissipate faster, thereby reducing the suction effect i.e. less power.
d)
BUILDING UP PRESSURE BY FASTER EXPULSION OF EXHAUST GASSES MUST NOT BE CONFUSED WITH BUILDING UP PRESSURE BY RESTRICTING FLOW. In the first instance, you will gain power, and in the second, you will lose power. Putting something in the path of the exhaust gasses will simply restrict the flow of gasses thereby SLOWING DOWN THE PRESSURE WAVES and reducing power.
e) One way to increase torque is to use smaller diameter piping. This will facilitate the building up of continuous pressure fronts since there is less space to fill. However, at the high end, this may become a restriction, so you will lose top speed.
f) The S-Muffler is a good idea to cut noise. One other thing you may do in addition to the S-Muffler is incorporate a simple non-restrictive bullet. DO NOT use the funny screw type bullets you see on the market. Those may work well with some cars by facilitating the outflow of exhaust gasses, but they WILL destroy the pressure pulses, which is the basis of how the Y-pipe works.