GENERAL INFORMATION

NOISE REDUCTION TIPS

Make sure your muffler is recommended by the muffler manufacturer for the particular engine in your vehicle. To meet most new noise laws, the “universal” muffler must be replaced by a muffler designed specifically for the engine.

Tail pipes on horizontal exhaust systems should be tipped toward the center of the vehicle to avoid noise reflection off the road.

If you have curved stacks, replace them with straight stacks. Noise coming from a pipe outlet is directional and straight stacks will throw noise up, not to the side. Rain stacks and 45° cut stack do not appreciably affect noise levels.

The length of the stack installed on the muffler can be critical. If an irritating “rap” is heard at certain engine speeds, try stacks with different lengths.

In an exhaust system with piping exceeding 10 feet in length, the muffler is suggested to be installed where the exhaust pipe to the muffler is either one-half or four times the length of the tail pipe.

A resonator can be used in-line with the recommended muffler for additional noise reduction.

If you have increased the size of the exhaust piping or made a dual out of a single system, check recommendations for piping size. Over-sized systems are exceedingly noisy!

The vehicle operator, to a certain extent can control his vehicle noise. The greater the engine load the louder the noise. Certain engine speeds may be more noisy than others. High vehicle speed causes more tire noise. Operating an engine brake when it’s not needed may cause extra noise.

If the above-mentioned techniques do not solve your problem, contact Grand Rock for specific recommendations.

MAINTENANCE TIPS

Keeping your chrome clean and waxed, not only makes it look good, but it also enhances longevity of the chrome finish. Road debris and other air particulates can play havoc on chrome finishes and other metal surfaces exposed to the elements. Grand Rock introduces their new complete chrome care line, which is designed to help battle these situations. Their DEOX, when used at the first site of oxidation, is designed to clean and deoxidize all metal surfaces. This product minimizes streaking, hazing, burning or etching of the surface, and is the safest way to prep the metal before polishing.

GLOW metal polish works the best with their DEOX to give your chrome that deep shine you’ve been looking for. GLOW can be used on several surfaces and can remove light scratches from plexy-glass, bug screens and even plastic lens covers.

SMOOTH is a no-silicone cleaning wax. Designed for chrome and stainless surfaces it is also excellent on clearcoats, glass, and plastic surfaces. It can be applied in direct sunlight and extreme temperatures and it literally DUSTS off!

Tips:

Make sure the exhaust system is properly supported with required brackets, clamps and braces.

DIESEL EXHAUST PRODUCT MATERIALS

There are several materials used in heavy duty diesel exhaust applications. Some of the materials are appropriate for heavy duty applications. Other choices are not durable at the temperatures generated by diesel engines, especially with new pollution control systems, and should be avoided to provide acceptable service life. Materials selected must not only survive high temperatures, but also withstand severe vibration, corrosive exhaust gasses, and external corroding agents such as salt and water.

The materials generally considered for exhaust parts are as follows:

Aluminized Steel is the preferred material for most heavy duty diesel applications. Aluminized Steel is a low carbon steel with a thin layer of aluminum alloyed to the surface. The aluminum provides galvanic protection for the base material. Aluminized Steel parts have an ultimate service temperature of 1250 degrees F with a continuous duty temperature of 1100degreeF. This material has excellent corrosion resistance to acidic diesel exhaust gasses. Aluminized Steel parts provide excellent field life at a reasonable cost.

400 Series Stainless Steels are used for extended service life in diesel applications due to their higher operating temperatures. This material family provides slightly better strength at exhaust system temperatures than aluminized steel. The most common 400 Series Steel that is used in exhaust applications is Type 409. It is stronger than aluminized but has cosmetic problems at exhaust system temperature. At first exposure to high temperature it discolors. Over time it develops a nondestructive coating of surface rust. After an extended time in the field a 409 product will display external discoloration and look worse than a similar aluminized part. Parts made with type 409 generally require some type of paint or other coating to slightly delay the onset of external discoloration. The parts will hold a magnet due to higher iron content.

Another type is 409 Stainless Steel with an Aluminum coating. Aluminized 409 SS are used on Diesel Catalytic Converter mufflers due to its excellent high temperature resistance and the corrosion protection of the aluminized coating. This is a premium material found primarily on emission products or high temperature gas applications. Grand Rock 400 Series products do not have a polished finish.

300 Series Stainless Steels are also used in exhaust systems. The most common material is Type 304. This material has excellent corrosion resistance and very good high temperature strength and is used in some muffler applications where very high stresses occur. It is also used as a premium material for gas applications. The most prevalent use of the material in diesel heavy duty applications is for flex pipe. Flex pipe produced from light gauge 304 Stainless Steel is an excellent choice considering all the factors of cost, durability, and service life. In general field service life with stainless steel flex pipe is very good if the flex tubing is installed properly. Grand Rock 300 Series products do not have a polished finish.

Galvanized Steel parts are sometimes used in the exhaust market. Galvanized Steel has very poor field performance. This material has an upper temperature limit of approximately 600 degrees F. At temperatures greater than 600 degrees the material rapidly corrodes with a resulting degradation in appearance and probable failure. Galvanized Steel is often used for flex pipe as a low cost replacement part. The initial low cost is offset by the limited field life of the product.

Cold Rolled Steel (CRS) is a very poor choice for any exhaust system part. This material is extremely susceptible to corrosion. These parts are only used when the lowest possible cost is desired. It is rare to find mufflers made of cold rolled steel, but there are stacks offered in some markets in Cold Rolled Steel. Clamps are another product commonly produced out of Cold Rolled Steel. Clamps are not exposed to the corrosive acids found in the exhaust gasses but the high temperatures cause clamps to degrade rapidly in appearance and in function. Cold Rolled Steel clamps can be very difficult to remove after a short time in the field.

Often Chrome Plated Cold Rolled Steel parts are found on exhaust system parts. This material is a reasonable choice when a bright mirror finish is desired. Corrosion from the inside of the product can still occur; Chrome parts are very challenging to produce. It is important to produce the parts with a high level of quality because surface irregularities and field damage to the surface will lead to external rust.