Well, what else is new? I’m always dreaming. This time it’s about exhaust. As I drove Lucy to work this morning with my iPod cranked to 10, I decided that the current exhaust system is too loud, especially at highway speeds. So, how do I get a quieter exhaust without sacrificing the performance gain I’ve experienced with the dual exhaust? Install a Big Single. For a couple years or so, a couple of Corvair nuts were producing a custom exhaust pipe made from larger diameter tubing. This assembly, pictured below, provided the much less restrictive flow of a dual system without the horrible drone. This design goes into a 3” diameter muffler. Here’s a link to a sound (.wav) file for a setup much like the one pictured, except it uses a Raptor turbo muffler.
Others have produced the same setup, but with slightly different approaches. The following one is built by cutting and welding together stock pieces (the standard Corvair u-pipes, 2-1/2” elbow, and 1-3/4” straight). The tricky part is forming the input end of the elbow for a good fit with the two incoming pipes. This one uses a 2-1/2” diameter muffler. One of the posts the producer of the previous product made is, “two 1-3/4” diameter pipes fit a 3" pipe; a 2-1/2” pipe will require 1-5/8” or 1-1/2" tubes.” One of the factors that will play into my decision about 3” or 2.5” mufflers is the diameter of Lucy’s current mufflers. If I can, I’d love to re-use one, but not to the point of going smaller than 2.5”. If they are only 2” as I believe they are, I’d need to buy a new muffler anyway and would probably go big for the visual affect since the price is the same.
Finally, one guy who must really love to weld came up with the following mega-custom job. While I enjoy welding, I’m sure I’ll have enough of a challenge creating good welds for the few I plan on making.
All these changes will be in concert with the installation of the 140HP four-carb heads and matching exhaust manifolds. I can’t wait to hear AND feel the difference. I need to get Ringo out of the garage first.