Moving along, I removed the Magnaflow muffler and tested, leaving the headers, CAT and Borla. The backpressure dropped only slightly, maybe by 1 to 1.5 psi, or about 3.5 to 4.5 total backpressure. The sound was much too loud, though. More than the Magnaflow w/o the resonator. That I expected, but the quality of the sound was not good, bordering on obnoxious. At least from inside the car, windows down. I don't think I'd run it that way at the track.
Next, I added the disc assembly to the tailpipe and retested. This time, the sound was much quieter than the baseline system (CAT-Borla-Magnaflow).
Unfortunately, the backpressure increased by a factor of two, I now got 8-10 psi @ WOT, and 2-4 psi when nudging it into boost, 2k-3k rpm. That is not acceptable. The long bolts supplied with the kit will allow more discs to be added. You could double the number of discs if you wanted to, but extra discs are not really cheap either, and no doubt would be louder. I did kind of like the look of them installed, and the weight was only a couple pounds, about 10 less than the muffler.
I'll bet nobody can tell what vehicle this muffler hanger-bracket came from (hint: made before most of you were born
)
