Beck TD, Part 90 - A New Exhaust System

 For the last 7 years or so, Beck TD has suffered along with a "temporary" exhaust system I cobbled together just to get it on the road. I guess it worked fine, but it didn't sound like a sports car, and it terminated under the car just ahead of the rear axle. It used a muffler off of a Honda, which fit but had no other virtues. Replacing that mess has been on the list for a long time, and it finally happened!

It was over a year ago that I bought the first component of my new system, after discussing it with Jake Roulstone. On his TD, he used a Smithy's muffler, which is advertised as "the world's oldest performance muffler" and "the muffler your dad used to impress his friends." It's similar to a glass pack, but instead of fiberglass inside, it has a steel wool that lasts a lot longer, and gives a nice rasp to the sound. It's now sold by Patriot Exhaust, which is a division of Pertronix, the company that makes that great ignition module to replace ignition points with reliable electronics.

Another great idea from Jake was to add a bracket to the exhaust downpipe to rigidly tie it to the engine block. In my case, that meant adding it to the stock Volvo downpipe that was on the car when I bought it. Who knows how old that piece was... 75 years? That Volvo part used a metric pipe in 44 mm diameter. That's very close to 1.75 inches, so I used a handy piece of scrap as a bending template.

My friend Troy was working with me, which was really handy. We mounted the downpipe in the car, and whittled on the bracket until it fit, and tacked it in place. After removal, welding and painting, it looked like this:

And here it is in the car. You can see how that added bracket ties into the heavy piece at the back of the engine block. No snark allowed about my welds - they are ugly but strong, and they don't leak!

The other part of the design was to add a flex coupling (10" long) to the back of the downpipe, and to weld on a flange so I could bolt the rest of the system together at that point. The coupling is 1.75" ID at the pipe, so it was easy to attach to the 44 mm downpipe.

Except... I needed a flange that matched the one I had for the 2" muffler inlet, but with a hole to match the outside diameter of the flex. I made it, and drilling and boring that center hole on my milling machine took a couple of hours.

I also bored the flange for the muffler so that it was a slip fit on the pipe, to make it easier to weld. That connection will make it easy to disassemble the system for maintenance.

The back end of the muffler conveniently aligned with a hanger I had made for the old temporary system. The 2" pipe out the back is just tacked in this photo, but I'll go back and fully weld it.

The final piece was to get the exhaust to the back. Like the stock TD, the system passes under the rear axle. I remember that Jake cut and welded his pipe to bring it up, but I cheated and used flex pipe. It was super easy and worked great! 

To mount the outlet, I welded on a little tab that mounts to a bolt for the spare tire mount. It put it in the perfect spot to be inobtrusive but reach all the way back.

And here's the view from the back, complete with my dented skirt. The car came that way, so I'm calling it "patina." The system sounds good, with a burble at idle, and a muted snarl on the road. Definitely louder than the Honda muffler, but now it sounds like a sports car!