I'm consulting on the build of a road race 365 SBC with SB 2.2 heads and exhaust & cam specced via the Dynomation engine simulation program. As the rules mandate a single 5" 40 Series Flowmaster, we also did DV-style expansion devices.
Will dyno it next month, checking back pressure with the muffler and power with/without. If I could figure out how, I'd post a pic of our terminator box..

 

A number of guys have mentioned cams. Per above post, I designed the cam with Dynomation and it predicts almost 60 HP more than for the one recommended by the engine builder. (we had it ground by Comp Cams and it came 2 weeks ago)
The engine should be on the dyno next month and we'll see how we did, but if you were interested in evaluating something out of the ordinary rather than just 3, 5 or ? of the most popular existing grinds, I would be prepared to come up with optimum cam specs for your appliction and you could get it ground and tested.

 

Hey, is this how to post a pic?

 

Ha, damn Bill, that thing looks crazy, ha ha. Could you explain that to mee a little. I see the primary portion of the collector I assume is inside that box but what is that enormous pipe in the front there. I've never scene one with the exit on the same side as the inlet??? Thanks!

I'm very interested in the results though. Do you have any projected power numbers for the motor. I'm looking for something to deal with just about 700 hp. Thanks.

 

Yeah, it does look a little bizarre! I've never seen one like it, so we'll either be heroes or zeros come Dyno Time.
The right side merge/megaphone collector is mostly inside the terminator box. The pipe is the collector & terminator chamber for the left bank, as seen in these pics. The reverse cone megaphone ends inside it and because it is so big (5") and extends upstream past the end of the meg, it does not affect the 'tune' of the exhaust system, which ends at the meg exit. Its volume is 12X one cylinder capacity and the muffler-like box in the above pic is 16X, well over Vizard's suggested minimum. The outlet of the box flows into the Series-mandated 5" Flowmaster.
(Oops!: Fat pix, will have to split them up...)

 

Dynomation says 750 HP @ 8,000 RPM. We'll soon see.
OK, another pic coming, the inside view of the left side meg in the 5" collector/'box'...

 

Ha, i'm confused, ha ha, wouldn't be the first time. In any event let us know how that turns out, i'd love to hear the results. I've still not selected mufflers for my car and if the flows turn out to not provide a restriction at that horsepower level they may be exactly what i'm looking for. Thanks Bill!