Thanks for all the replies so far guys.
I think what I will do for now is just stuff the biggest turbo or OE type muffler where the current one is and drive it. Realistically I probably won't make it to autoX this year with it (and I shouldn't with a stupid hernia anyhow). Over winter what I will try is: cut longtubes shorter, weld a new collector on, and fit a second muffler in the gained space. After that, aim the tailpipe correctly and see where I am at. Fortunately I have the same sound meter that autoX uses so can test. The biggest problem is going to be higher rpm noise. Engine gets very loud around 4000-4500+. I'm sure I am
well over 100dB. I'd love to get the tailpipes out the back but don't think it's viable. Interestingly though the Buick Regal this engine comes from only has one fairly small 2" muffler with about a 30" resonator (and cat/manifold). They are really quiet.
Comments:
-Auger insert probably won't help much, but if I am close I will try that. Thanks for reminding me of them.
-I have a perfectly good s/c, I don't need to ruin its nice stable powerband by putting silly turbochargers on :þ Pretty sure straight through mufflers of any type are going to be too loud.
-45° to ground is better than straight at ground? I figured it would be better to hit the ground and bounce up, away from the sound meter.
-Mark, my little camera has a bad mic so not much luck there. This is the only video so far:
https://www.youtube.com/watch?v=30DD-Y8pBi0 At 4 seconds the sound is painfully loud. Car is now registered (hooray) so you'll have to see it in person :þ
Thanks again for the help.