Well, it's done.
I mocked up the muffler myself, took pictures I printed off from this board to places to show how I wanted it welded up, and finally found someone who would do it. Cost me $180 for him to weld it up, cap off the 2nd out and to weld up a crack in the original welding where the two heat exchangers outs meet and turn into the single pipe that goes to the muffler. Seemed a tad expensive but at that point I was just happy he said he could do it.
My initial impressions are good. There is no drone inside the cabin at any RPM so far. The exhaust note is good, definitely better than stock, and has a really nice build as the RPM's climb during acceleration. Also, the pops and grumbles during decceleration are much more audible now, which sounds really cool as well. In all honestly though, I could stand for it to be even a little more aggressive and raspy, but this will do.
As far as performance, the FM weighs less than half of the stock muffler (which is an absolute BEAST in size and weight), so that's a help. But the only thing I've really noticed performance-wise is that the power seems to kick in a little earlier than before. With the stock muffler 3500RPM is where I'd feel the car really surge. Now it seems like that same surge is coming at 2700-2800 RPM. The surge
feels the same, but it comes on earlier. I am guessing this will mean the surge
ends sooner as well and leave me with less usable high-end RPM, but I am never really over 5k anyway.
Anyway, here is a pic and a video I made. I'm gonna post the video in the Ultimate exhaust thread as well, but since you are already here I am posting here too.
YouTube - 1974 Porsche 911 (with SC motor) exhaust note comparison (stock, open headers, Flowmaster)
