Noise And Flow
If you're looking for a whisper-quiet exhaust that offers maximum flow, then you're out of luck. Although manufacturers are always trying to find a balance between flow and noise output, the more a muffler flows the more noise it will emit. "An OE muffler uses containment technology, which is very restrictive and traps sound waves," Scott says. "The byproduct is that it also contains the exhaust instead of letting it flow through the muffler. By increasing flow through reflection, refraction, and absorption, noise output will increase; fortunately, there are hundreds of mufflers on the market to suit all applications and tastes."
Manufacturing Process
"Something most people don't realize is that Dynomax is part of Walker, which is one or largest OE exhaust suppliers in the country. The benefit to us is that when there's a new car on the market that may sell 300,000 units per year, all the technology that allows us to produce exhaust systems in such high volume to such exacting standards goes into our aftermarket systems as well. Our fixtures, jigs, and tooling are unparalleled, and we have far more data points than most competitors. That's one of the keys to why our products fit so well. Being an OE supplier also gives us the ability to come to market quicker with new products when a new vehicle platform is released."
Underhood Heat
Using ceramic coatings is one of the best ways to reduce underhood temperatures, but there are other effective techniques to consider. "Outside of coatings, header wrap works best at reducing heat, but it also retains moisture and causes rust," Scott explains. That said, most people who run turbos use header wrap extensively, so it's definitely effective. "Header boots are another alternative, which cover just the critical areas and are easier to install. High-temp plug wires and shrouds can also be used to protect important components such as brakes lines and starters. Even with coated headers, maintain at least a 2-inch air gap between the headers and other components to allow sufficient heat dissipation."
Power Adders
For any given power output and displacement, a generic sizing chart can get you in the ballpark when choosing exhaust-pipe diameter. However, engines equipped with power adders have a different set of needs. "If you're running a turbo or supercharger, there's really no such thing as an exhaust that's too big," Scott explains. For forced induction, the bigger the better. "In a race application on a nitrous motor, the exhaust should be built in respect to the max horsepower it makes on the bottle. Conversely, in a street application with nitrous, the exhaust system should be built in respect to the maximum horsepower the motor makes off the bottle. That way, you'll optimize the exhaust system for the operating conditions that the engine sees the most."