07 May The Finishing Touches: SL600 Exhaust
Today, we’ll be putting the finishing touches on Tom’s Mercedes SL600 exhaust.
The first, quickest and probably least exciting part of these finishing touches is the addition of the oxygen sensor bungs in the midsection’s oval portion. A quick boring out of the side of the pipe, followed by tacking and welding the bung in place, is all that’s necessary to get these oxygen sensors plugged into the correct spot.
From there, we still have a couple exhaust hangers to address. The first is just before our crazy miter-cut circle-to-oval transition. In order to get the hanger closer to the new exhaust layout, we fabricated a hanger extension that would move the rubber exhaust mount a bit closer to the pipe. From there, as we do with almost all our exhaust hangers, we took some stainless steel rod to our vice, where we used the acetylene torch to heat and shape the metal to sit flush against the pipe. A few welds later, and we have ourselves one solid exhaust hanger. Tolerances are tight in the SL600’s exhaust, so we have to make sure the exhaust is mounted with enough rigidity to not contact some of the nearby components attached to the car’s underside.
That leaves us with one remaining exhaust mount, located midship just ahead of the double bottle resonators. There was an existing OEM brace already in place there, but sadly its design does not fit with the custom exhaust setup. Therefore, we took some flat steel and once again used the acetylene torch to form it appropriately. Coming off each end of the brace, we fabricated a set of mounts that will hold the polyurethane exhaust mounts to the brace. Then it’s back to the vice, where we formed more stainless rod to connect the top of the exhaust to the polyurethane mounts.
Finally, we’ve reached the end point of this exhaust — the tips. As we mentioned before, the customer will be looking for something with a great deal of civility under most situations. Seeing as how there will be a chance to get a little loud with it, we’ve decided to install switch-actuated valves on the exhaust tips that will mitigate flow in order to cut down on the noise (but not so much that it chokes the engine out, obviously). By tweaking their positions, we’ll be able to keep the car relatively quiet unless the owner wants to start making some noise. We took a set of valves that we had in the shop and repainted them with black paint and underbody coating to protect the valves from the environment, as they’ll be connected between the exhaust tips and the mufflers.
Now, we have to get a little tricky again. As you saw in the above pictures, the outlets of the exhaust tips are a bit larger than the outlets of the mufflers, requiring piping of two different sizes on the exhaust valves. Seeing as how our desired size of turndown is proportional to the exhaust system itself, and seeing as how the valves are a little smaller, the turndown tips would be displaying the valves rather awkwardly. Our solution is thus — by running dual pipes on the exhaust tips, we’re able to conceal the valves, while at the same time only displaying the fact that it’s double-walled to those who are looking at the car from underneath. Once the car starts running and the soot and fumes from the exhaust start to darken the inside of the pipes, it’ll be effectively invisible.
And with that, we have ourselves one completed Mercedes SL600 exhaust. However, we will have more on this car coming in the near future, so stick around and stay tuned for even more Mercedes goodness coming your way soon! Have a great day!