What is the major benefit of using SuperTrapp products?

Tunability, quality, and years of performance exhaust experience and testing. We do not release SuperTrapp products to the market unless we can show a documented performance improvement. SuperTrapp tunable disc mufflers have been proven to make power for years. The reason is that SuperTrapp discs provide a scavenging effect. Here’s how it works: the gap between each disc ranges from .023-in. wide on the inside of the muffler, to .028-in. on the external open edge. As hot exhaust gases pass through the discs to exit the muffler, they enter a larger area, creating a slight pressure drop as the gas expands, creating a scavenging effect for the hot gas still inside the muffler. Adding discs increases the size of the exhaust outlet area. Removing discs decreases the exhaust outlet surface area. Many competitors have tried to copy our disc design, but have never been able to duplicate the performance of genuine SuperTrapp discs.

Tunable Disc Technology
Disc Installation Video

How do the diffuser discs work?

SuperTrapp is the original tunable muffler. The SuperTrapp exhaust system allows you to adjust, or “fine tune,” the sound level, powerband and performance. SuperTrapp’s exhaust outlet is formed by a precise gap between a series of individual discs. Adding discs increases the size of the exhaust outlet, increases exhaust flow and exhaust tone while reducing backpressure. More discs move the power band up to give you more top-end power, and lean out the carbureted fuel mixture. Removing discs decreases the size of the exhaust outlet, decreases exhaust tone, and exhaust flow while backpressure is increased. Fewer discs tend to increase low-end torque and richen the carbureted fuel mixture. Diffuser discs allow you to compensate for changes in altitude and air temperature without re-jetting or changing your air intake. And, besides reducing noise, our discs function as United States Forest Service-approved spark arrestors (USFS T-102), making them a safer choice for off-road motorcycles and ATVs.

Tunable Disc Technology
Disc Installation Video

How many diffuser discs should I run?

The answer depends on your displacement: disc diameter, power band, and noise level. Fewer discs reduce sound levels, more discs increase sound levels. Fewer discs increase low-end torque and richen the carbureted fuel mixture. More discs increase sound levels, increase top-end power and lean out the carbureted fuel mixture. NOTE: When tuning an exhaust system, start with fewer discs and add. Never start with a lot of discs and subtract. Generally on a stock set up (no engine modifications, and stock carb and air filter), you can start with six to eight discs on dirt bikes and ATVs. On V-twin, metric and cruiser bikes, start with twelve discs. A popular misconception: The more free-flowing an exhaust system is, the more power it will make. This is not true. Some backpressure (2-3 PSI) is necessary to achieve maximum power. This is why it is necessary to use the discs that come with your tunable SuperTrapp exhaust. The number of discs to use will depend on your application, displacement, disc diameter and power band. To assess the performance of any product that affects horsepower and torque, lap times and Dyno- runs are your best indicators. However, since most enthusiasts usually only have a “seat-of-the-pants” Dyno, running condition is the most obvious indicator. Pay attention to the coloration of the discs. Little or no disc coloration indicates a possible lean condition (remove one or two discs). Black or sooty discs are indicative of a rich, or oil burning condition (add one or two discs). Discs that turn a tan or golden color indicate an acceptable balance of fuel mixture and exhaust flow. Reading a spark plug is the quickest way to check if everything in the engine is working as it should. And, it will tell if the SuperTrapp has been tuned properly. A rust-brown spark plug color indicates that the plug is operating smoothly (exhaust is tuned correctly). A whitish look indicates that the burn is too lean (remove one or two discs). A blackish deposit on the plug electrodes (left by oil or fuel traces) indicates that the burn is too rich (add one or two discs).

Tunable Disc Technology
Disc Installation Video

How do SuperTrapp mufflers reduce noise?

Sound energy in SuperTrapp mufflers is reduced in two ways: it is absorbed through a perforated core inside the body of the muffler, and it is diffused 360º radially as the exhaust passes through the discs. The number of discs used determines how much total sound energy will be absorbed and diffused. Fewer discs will have less open area and tone down the exhaust note. Most mufflers today reduce noise levels in several different ways, such as sound absorption, reflection using baffles or resonating chambers, or restriction. Physics tells us that air in motion does not like to change direction. Original equipment mufflers typically change the direction of airflow 90° to 180° several times as it passes through chambers or is deflected by baffles.

Tunable Disc Technology
Disc Installation Video

Will removal of the packing material increase performance?

In general terms, no. Example: A firmly packed SuperTrapp exhaust equipped with a 1-1/2-in. diameter core will maintain the same flow characteristics as the 1-1/2-in diameter exhaust tube that flows into it. However, if the material surrounding the perforations of the core tube is removed, or severely worn, this allows the exhaust to flow in and out of the perforations. This in-and-out movement introduces unwanted turbulence into the exhaust path. Consequently, this can harm the flow and performance.

How often do I have to re-pack?

Re-packing should be considered when you notice that your exhaust is getting louder. SuperTrapp’s IDS Series and Kerker’s Performance Series are packed with a newer, better performing pillow pack sound absorbing material. If your exhaust is an older pipe, we suggest that you use pillow pack packing as it provides a slightly deeper sound and lower volume.

Video: How to Re-Pack a SuperTrapp Exhaust

How do I repack my IDS2?

To replace the packing, or remove the core, follow these six steps:

  1. Take the muffler off of the bike.
  2. Remove the end cap (three screws hold it on).
  3. Remove the screw that is on the bottom of the backend of the muffler (holds the core in).
  4. There are two rivets holding the nameplate. Drill out the rivet nearest to the back end of the muffler.
  5. Put a dowel, or similar type of handle, into the inlet end of the muffler. At this point it will either hit a screen, or it will go all the way down to the discs. Tap against the discs, or the screen, and push the core out the back end of the muffler. If you have a Quiet Core you will have a screen. If you have a Race Core you can see straight through to the discs.
  6. After removing the core, remove any left over packing. Next, make sure the holes in the perforated tube are clear. Wrap the new packing around the tube. Use masking tape at the top and around the middle to hold the packing in place. Then line up the holes and replace the core.

Video: How to Re-Pack a SuperTrapp Exhaust

Do I need to re-jet?

Re-jetting is suggested, but is not required. The best approach is to first put your new tunable SuperTrapp exhaust on your bike, or ATV, and tune it to the stock set-up. Once the SuperTrapp is tuned and running the way you want, you can then go up in the jet sizes, add a free flowing air filter, and add more discs for more horsepower.

Will I be able to maintain my center stand and drain plug access?

The majority of SuperTrapp/Kerker systems have been designed for easy access to the drain plug and retention of the center stand.

What is the warranty on SuperTrapp exhausts?

All SuperTrapp products come with a limited one-year warranty against workmanship and mechanical failure. For warranty questions Click Here to call us or send us an email.

How tight should disc screws be?

Fifteen inch-pounds. Or, two more turns once the screw heads hit the discs. Then check after your first ride and make any adjustment. Note: It is very important that you liberally use an anti-seize lubricant on the screws that hold the discs onto the core.

Disc Installation Video

Do disc screws need Locktite or an anti-seize compound on them?

Yes, an anti-seize lubricant should be used. These compounds resist heat and moisture and will ease the future removal of the fastener. Do not use Locktite, as it is an adhesive thread-locking compound. We recommend using a high temperature, copper based anti-seize lubricant.

Disc Installation Video

What is the difference between a 2:2 exhaust system and a 2:1 system and why does a 2:1 provide more power?

It really depends on how you define power. A lot of information available boasts peak power numbers, these numbers are usually at an RPM range that most bikes rarely see. To really understand how a system performs you need to look at a Dyno graph all the way through the RPM range. There are a lot of factors that affect where a pipe makes power. Engine size, compression, cam timing, cam overlap, valve size, and intake size are all part of the equation. The biggest factor to consider is at what RPM range the bike will be ridden at consistently. The fact is that pipes designed for race bikes, which are ridden in a very narrow high RPM band, will not perform on a street bike. A general statement that can be made is; longer smaller diameter pipes make low-end power and shorter large diameter pipes make top end power. One other design constraint to remember is styling. Everybody has his or her own opinion on what’s going to look good on his or her motorcycle. Drag pipes just wouldn’t be drag pipes if there was a collector stuck on the end of them. With all of this in mind, there are a couple of fundamental differences between 2:2 and 2:1 exhausts when it comes to design. The advantage of a 2:2 is that the pipes are separate so the length can be fine tuned for a specific power band. You can also tune each pipe length per cylinder if necessary. Also, you have far more styling latitude. The disadvantage is that the power band is narrower. The advantage of a 2:1 is that you tie the cylinders together giving you the ability to take advantage of the natural scavenging affect that occurs between the cylinders during the intake and exhaust valve cycles. This tends to give you a far broader power band and greater overall performance.

Why do some aftermarket pipes backfire when you decelerate?

Backfire, or “lean misfire” on deceleration is primarily attributed to an improperly tuned engine. Under this circumstance, the low speed fuel circuit needs to be adjusted. On a street bike, the rule of thumb is to adjust the fuel mixture screw out in ½ turn increments to add fuel. If you reach 3.5 turns out and it still pops on decel then go up one size on the pilot jet and turn the fuel mixture screw back to one turn out from bottomed. Repeat this process until the misfire is eliminated. In some cases, this problem is an indication that the exhaust is too free flowing (i.e. Head pipes too large in diameter or muffler core is too large) for the motor configuration you have. As always, check your spark plugs to verify the tune is correct. The plugs should be a light tan in color if tuned properly. If the exhaust is too “free flowing” you will ultimately add too much fuel which will cause an excessively rich condition and foul the plugs.

How does the length and diameter of an exhaust effect sound?

If we’re talking about straight through pipes with no mufflers/baffles then a smaller diameter pipe will give you a snappier sound (high frequency) and a larger diameter pipe will give you a deeper sound (low frequency). Longer pipe lengths lessen the volume of sound and shorter pipes increase the volume of sound. Something to keep in mind is that the human ear is more sensitive to higher frequencies; this means that we perceive these sounds as louder. If a muffler or baffle is added to the equation then the pipe size has only a minor affect on the overall sound. Also, a muffler can alter sound significantly depending on the design. Many technologies are employed in the design of mufflers or baffles. At this point we need to understand the difference between a muffler and a baffle. A muffler is a mechanical assembly that employs multiple components and technologies to reduce sound in an exhaust system. A baffle is a mechanical device used to disrupt sound waves. In most cases baffles are used as a component in a muffler assembly. The term “Baffle” has become common these days because of their use in drag pipes. They’re used in drag pipe designs due to the limited space inside of the pipe. Muffler assemblies are far more complex. These assemblies can incorporate many components to alter sound waves. These components can range from packing materials such as fiberglass, ceramic wool, and stainless wools to perforated tubing, baffle tubes, and baffle plates or any combination of these components. Due to the vast design configurations and their abilities to manipulate sound, there is no hard fast rule that can be given to say how a specific muffler will sound. Unfortunately, as we’ve learned, “you cannot muffle horsepower”. All street exhaust designs are a balance between power and appropriate sound quality. Something else to keep in mind is that the engine configuration plays the biggest part in overall sound. Compression ratios, cylinder heads, cams, and ignition timing all affect the sound output of any given engine.

Do you have to take the complete exhaust system off to change slip-ons?

No. Slip-ons are just as they infer. Loosen the clamp at the inlet of the muffler, remove the mount bolts from the muffler and remove the muffler from the bike. Reverse the process to install the new mufflers.

What does a performance exhaust do? Does it give more power?

A performance exhaust is designed to improve airflow through the engine. Anytime you can improve the efficiency of airflow through a combustion engine you can increase performance.

Tunable Disc Technology
Disc Installation Video

Why should I use discs?

SuperTrapp discs provide a scavenging effect. Here’s how it works: the gap between each disc ranges from .023 inches wide on the inside of the muffler, to .028 inches on the external open edge. As hot exhaust gases pass through the discs to exit the muffler they enter a larger area, creating a slight pressure drop as the gas expands, creating a scavenging effect. This larger charge lets the engine create more power and this is why it is very important to use discs. It’s simple physics and math: a quantity of gas expanding to fill a larger volume results in a reduction of pressure and as the circumference of the circle increases, its area increases by more than twice as much.

Tunable Disc Technology
Disc Installation Video

How do I know which way to install my discs?

The discs are always installed with the flat surface against the end of the muffler and the tapered outer lip pointing away from the muffler. Additionally, our 3” and 4” discs have “SuperTrapp” stamped on the inside of the disc that faces away from the muffler. Our 5” discs have “SuperTrapp” stamped on the flat side of the disc that goes against the end of the muffler. Always remember to use an end cap with the discs. The end cap is formed to nest into the discs and is an additional indicator of the correct installation direction.

Download complete instructions HERE
Tunable Disc Technology
Disc Installation Video

How do I know if my bike is tuned properly?

Check the color of your spark plugs.
White / light tan = Too lean. You need to remove discs.
Coffee with light cream = Just right.
Dark = Too rich. You need to add discs.
Click here to view an example of these 3 spark plug colors.

What is the difference between a Closed End Cap and an Open End Cap?

Watch our video for a detailed explanation and demonstration.
Closed End Cap vs. Open End Cap Video

How do I find the part number for my exhaust?

Part Number Location Video