Sport Muffler Fab Question, best methods Options

[tomrev]

Some background: My 914 has gone from a 383Chevy, to a 283, and now Honda 3.5 V-6 engine. A backwards power curve. The Chevy's just didn't sound the way I wanted the car to sound, so the move to the Honda. When it was finished, I re-cut, and re-made a system for the Honda using the twin Dynomax mufflers from the Chevy system, with 2 1/2in main pipes into the mufflers, and 3in. exit pipes. Kind of big for a 3.5, but it was 304 stainless, and I already had it. The car sounded quiet at idle, and glorious at open throttle, a cross between an NSX and a big 911. However, at cruise, and mid revs, ( 2K to 2800) it was pretty boomy, drony, too much so. I took it apart, re-did the pipes, and used a stock early 70's Leitritz banana muffler. Now it is too quiet! My current plan is to convert it to a sport muffler, and not having built one for 25 years, I'm asking those who have if they were able to make them without being too loud, or if a twin in, twin out is inherently going to drone. In my pile of stuff I have some 304 pipe in 2 1/2in. OD. Would this be too big for the exit side? Most sport's seem to have the exit pipes about 12-14in. apart, from the center; are there any inner chambers I can not fuch up by locating the exit pipes in a certain spot? Thanks! (photo of the Chevy system)

[mgp4591]

Someone not too long ago took similar mufflers to your Dynomax and ran 90 degree elbows toward the rear center and welded them to a large diameter long glasspack, then drilled two large outlets for tailpipes exiting center about 6 inches apart. He claims the sound was just right- I wish I could remember the builder but I'm too lazy to look it up and it's past my bedtime... (IMG:style_emoticons/default/yellowsleep[1].gif)
And looked cool as hell.

[tomrev]

Someone not too long ago took similar mufflers to your Dynomax and ran 90 degree elbows toward the rear center and welded them to a large diameter long glasspack, then drilled two large outlets for tailpipes exiting center about 6 inches apart. He claims the sound was just right- I wish I could remember the builder but I'm too lazy to look it up and it's past my bedtime... (IMG:style_emoticons/default/yellowsleep[1].gif)
And looked cool as hell.

Would be interesting how he fit all that back there; would be cool to see it from underneath. The big reason I reverted to the Leitritz was packaging, to take advantage of the original design, and weight is pretty light. Thanks!

[76-914]

This? http://www.914world.com/bbs2/index.php?s=&...t&p=2295647

[Mueller]

Some background: My 914 has gone from a 383Chevy, to a 283, and now Honda 3.5 V-6 engine. A backwards power curve. The Chevy's just didn't sound the way I wanted the car to sound, so the move to the Honda. When it was finished, I re-cut, and re-made a system for the Honda using the twin Dynomax mufflers from the Chevy system, with 2 1/2in main pipes into the mufflers, and 3in. exit pipes. Kind of big for a 3.5, but it was 304 stainless, and I already had it. The car sounded quiet at idle, and glorious at open throttle, a cross between an NSX and a big 911. However, at cruise, and mid revs, ( 2K to 2800) it was pretty boomy, drony, too much so. I took it apart, re-did the pipes, and used a stock early 70's Leitritz banana muffler. Now it is too quiet! My current plan is to convert it to a sport muffler, and not having built one for 25 years, I'm asking those who have if they were able to make them without being too loud, or if a twin in, twin out is inherently going to drone. In my pile of stuff I have some 304 pipe in 2 1/2in. OD. Would this be too big for the exit side? Most sport's seem to have the exit pipes about 12-14in. apart, from the center; are there any inner chambers I can not fuch up by locating the exit pipes in a certain spot? Thanks! (photo of the Chevy system)

And a nice video of this glorious sound is where? (IMG:style_emoticons/default/smile.gif)

[tomrev]

This? http://www.914world.com/bbs2/index.php?s=&...t&p=2295647

Interesting reading; I will stick with the banana, and probably do the usual twin pipe exits. Just hope it doesn't revert to being too loud.

[rnellums]

If drone in a specific Rev range is your issue look into a Helmholtz pipe. It's a flawless acoustic pipe designed to kill noise of a certain frequency. I'm going to try to implement it on my droney exhaust later this summer.