Here are a few pix of an exhaust resonator I'm workin' on to quiet down that Thermal 3".
I've made a flex joint very much like the factory style (only bigger) instead of the typical flex-tube style.
Here ya go:
Here are the parts I used:
(1) piece of 3" x .065 wall stainless and drilled 5/16" holes in it.
(1) piece of 4" stainless tubing
(2) endcaps made of 11 gauge stainless - 4.00 O.D. x 3.06 I.D. (These slip over the 3" piece and butt up to the ends of a 4" diameter piece.
(1) O2 bung
(1) 3" x 3 bolt flange
(1) 2.5 to 3" adapter flange (I made this flange out of a piece of 5" diameter x 1.5" thick steel). I flared it to 3" on the resonator side and tapered it on the other side to fit a ball-type pivoting flange like the stock Honda style. Where those 2 diameters meet in the middle of the part, it measures 2.56" to be fairly consistent with the 2.5" downpipe. The outer part of the flange is 1/2" thick. (overkill)
(1) radiused-type pivoting flange to allow for flex. I couldn't see paying $29.00 for a Honda one, so I made one at work (during break, of course ) on a CNC lathe I run. I made the O.D. 3" and the I.D. 2.520" to slip over the 2.5" downpipe. I don't know if the material is adequate, but I'll find out one of these days. I used aluminum for this. The design is like stock where the "gasket" has a radiused outer surface that fits into a tapered flange section that allows for flexing of the motor without losing a seal on the exhaust. I'll also be using the factory exhaust "springs" (to permit the flexing) with stainless hardware .
I may put some type of fiberglass? packing between the 3" and 4" pipes for added quietness.
I just need to weld it up now.



Resonator and pivot gasket for downpipe...


Inside the resonator...


Partially assembled, but not welded...

 

wow, so what are you gonna call your exhaust shop now? heheh

 

Damn...make me one.

Well, let us know how well it works!


[Modified by TheShocker, 6:01 PM 8/4/2002]

 

I'll let you know how it does. I've made one of these before for my old JRSC '94 GS-R. It was 2.25" pipe w/ a 3" can assembled like the one above, but it wasn't stainless. With no resonator at all, it sounded like a damn dump truck!!! Way too loud! Just the resonator (with no fiberglass packing) it made a huge difference in noise and as you can see, it shouldn't be any more restrictive than a straight pipe.
Y'all take care,

 

damnnnnnnn that is clean and professional!! i'd start sellin those

 

I made one like that, but I used 2" inside w/ 3" outside PVC for a silencer for my potato gun.

-Dustin