R muffler how-tos

[mjmoran]

I am going to convert one of my mufflers to an R/ST look to go with my new rear R bumper on the 68. I have a 74 muffler for the donor, but would like input on what others have done to complete the cut...I have done (a long time ago) the sport type that was written up in Pano in the early 70's, but this one will have a much wider stance in the exit pipes.

Any picts, diagrames, dimentions, whatever tips you have...bring them on!

Cheers,

[ttweed]

M-
Here is the diagram from Pano.



I don't think it would make much difference how wide you put the exit pipes if you cut open the top-front of the shell to do the mods on the baffles. The way they describe it, the left exit hole is what you use to cut the holes out of the internals. If you move that over beyond the left side bulkhead, you won't have access to the places you need to torch out. If you remove the lid from the shell on top between the bulkheads, all can be accessed and then the shell welded back up, so you can put the exit pipes on the ends if you want.

I recommend a stock look with the same single left exit, and torching the holes as described along with cutting out the "slotted pipe" section entirely. This was shown to me by an oldtime '67S owner/autocrosser/timetrialer in our club, and it worked great for me on a 2-liter S motor, while keeping the sound below 93 db @ 50', which is the limit for our venue.

If you want the dual pipes out the back, then do what you gotta do.

TT

[mjmoran]

Thanks Tom, I have this article...with the new rear bumper, I can not have the three out with caps as I have on my 67. Here is a picture of what I will be doing. The only problem (and its only a problem with the rest of the traffic) is that the exits will be right on top of the inlets with the placement of the cut-outs on the valance. Well, looking for some internal baffleing that I can stuff inside the 3"OD SS pipe I have for the tips.

[ttweed]

M-
10-4.
You might try some of the Schoenfeld Headers muffler inserts in the 3" exit tubing to cut the noise, then.

TT

[cosley]

Here are 2 mufflers I did. The white lines represent the stock pipes. The shinny metal is what I welded in. The second muffler I made for our race car. I took a stock muffler and took out 2 ft. in length and 14 lbs. in weight. Now weighs 11.5 lbs. Also has welded in baffles. I made slip in baffles to quiet them down for the street.
The problem I see with the R muffler is you essencially have the exit pipes pretty much in line with the entry pipes. Unless you weld in some baffles to divert the exhaust around it's going to be really loud.

[cosley]

I use s/s wool for sound absortion. I used it for the innards of my custom crewcab muffler, and also to wrap the slip in perforated pipes for the 2 sport mufflers above. Very effective stuff. You need to do a search for s/s wool, I only found one source on the east coast that sold it. It was around $50 for 50', about 3-5" wide.

[mjmoran]

Those baffles look like they might be the answer...thanks Tom. I may also try removing some of the extra pipe as you did Cosley. Thank you both for the input...now, anyone who has already done this want to chime in?

[mjmoran]

Looks like the orange car in the Monteray pictures and this months Excellance has the same muffler idea that I am looking at...Rob, who did yours???

Cheers,

[bob tilton]

what about a "triple-out" muffler with cap(s)? there are few cars running with that set-up around here. they sound wicked!

[mjmoran]

Yes, I have one of the old tripple outs with cap's...and my original thought was to use it. There is no outlet on the side and the two rears are not in the correct place...so the muffler will not fit correctly.
When I saw that muffler on the 69 orange coupe in the Monteray pictures, I knew how I had to have mine...just hope its abit more muffled than the megaphones! I may try Toms suggestion on the schoenfelds.
What set-up do you have on your 68 Bob? I seem to recall that you have an R rear bumper as well...