It’s no secret stock dirt bike exhausts are choked up, heavy and ugly from the factory. In many cases, a seemingly underpowered machine can transform to race-ready, with the help of just a simple after market exhaust pipe.
There are many reasons many riders, from the track to the trails, upgrade their stock exhaust:
• More Power- An aftermarket exhaust is one of the easiest ways to add a few horses to your ride. Exhaust manufacturers spend countless hours on the dyno and at the track developing exhausts that deliver peak performance and power delivery.
• Pass Sound Inspection- If you race off road, it's likely you’ll have to wheel your bike through tech before racing. There the race officials will test your bike’s sound level, and if it's too high, you’re not racing. This may seem harsh, but noise pollution is one of the leading reasons why many riding areas are being shut down. A new off road specific exhaust will give you more power and keep those decibels low.
• Spark Arrestors- If you ride local trail systems or ORV areas, you’ll undoubtedly be required to have a spark arrestor. These eliminate sparks from the exhaust escaping, which in tern keeps the forests alive and available for you to enjoy.
• Weight- One of the easiest ways to shave some undesired weight of your bike is to upgrade to a new exhausts. Most riders could care less about a few pounds, but for the serious racer, it can make all the difference. Depending on the metal and materials used, you can lose around 1-3 pounds from a new exhaust alone.
Let’s take a quick look at what all makes up a motocross or off road exhaust system:
Four Stroke: Starting with the thumpers, as most bikes sold today are four strokes, really benefit from having an aftermarket exhaust. Most modern bikes come fairly choked up in stock condition. Here are the two major options that most riders choose.
Slip On: the first choice for most riders, and for good reason! As the best “bang for your buck” modification for your bike, slip on exhausts can open the bike up, add horse power for relatively cheap. Compared to a full system, you’re looking at half the price, and half the installation time as well (general install takes about 20 min). Other reasons why riders and racers alike, go with a slip on is for adding a spark arrestor, and keeping the DB’s down (we’ll get into this more in a bit).
Full System: replacing your full system is the ultimate option for those who want big gains across the powerband. A full system includes a header and most likely a mid-pipe. Now you have a performance designed exhaust from front to back. A complete exhaust system can be more expensive than a slip on, however it still is substantially less expensive than engine and ECU modification, making it one of the best economic upgrades to your bike.
Two Stoke: Less strokes, less weight, less expensive and less exhaust parts when it comes to two stokes. The mighty two stroke takes things back to a simpler time with just an expansion chamber and a silencer. But don’t let the simple design fool you, there are many exhaust options for those still mixing premix.
Pipe: The expansion chamber, or what is often referred to the “pipe” bulges out of the cylinder exhaust port before it tapers back to the silences. FMF and Pro Circuit are the major players left in the two stroke market, both offering a motocross and off road pipe in a stainless nickel-platted and a raw metal finish (the “factory” look). The motocross pipes have tend to add more over-rev and “hit” without sacrificing any low end power. One special thing to note, is that the raw metal finish requires a coat of WD-40 and some elbow grease to keep looking factory. The off road style pipes are gear towards making more torque and low-end power for enduro riding purposes, and have thicker grade steel for added durability. You can also add a pipe guard or protector to combat those pesky rocks or trees out on the trail.
Silencers: Meeting the end of the pipe, the silencer helps quiet that ringdinger down. Like pipes, there are two categories of silencers: off road applications and motocross. For motocross, silencers are generally shorter, and a bit louder, but increase power (especially from mid to high range). Off road silencers tend to compliment the off road pipes, by increasing torque and low end power. Perhaps the biggest reason for an aftermarket silencer addition is for the spark arrestor or quieting features. It’s worth noting that most riders purchase the pair together, however most two stroke systems are less than a single four stroke slip on.
Chances are, if you aren’t getting an exhaust for performance reasons, you’re getting one because you need a spark arrestor. Most public riding areas or trail systems require you to have a spark arrestor to prevent forest fires and to keep sound exertion down. Many enduro or hare scramble type events require a screen type arrestor as well. To take it a step further many racing organizations even have mandatory sound checks to compete. Don’t be mad though, these hoops to jump through are a small price to pay for keeping riding areas open for years to come.
Most four stroke exhaust systems or slip ons come with a removable sound insert and spark arrestor screen. Some exhausts are quitter than others, and also designed for trail and off road specific types of riding. Others are full blown race pipes that have the bare minimum to keep you legal. What you choose is up to you and what you need. The cheapest way to add a spark arrestor to your stock system is to buy a special end cap that is fitted with a spark arrestor. These can be had for less than $100 and are great for those who don’t want more power or aren’t concerned with weigh.
Two strokes are a bit different as the only silencers with spark arrestors are those that are designed for off road and trail applications only. Many riders choose to have a spark arrestor silencer for the trails and a regular silencer for the track.
When looking through our selection of exhausts, you’ll see different materials or metals used for the same model or brand pipe. In general, there are no performance changes from one metal to the next, but the weight savings and durability do. The cheapest and most durable are stainless and aluminum. These tend to not dent as easily, are much cheaper, but are much heavier than the ultra-light metals (still lighter than stock). Most high-end exhaust systems come in titanium with carbon elements, such as the can, end cap or mounts which can lead to savings of 3-4 lbs. The thinner and lighter metals can be less durable in some cases, so depending on your riding style or conditions, you may want to keep that in mind.
Love your exhaust and your exhaust will love you! Well…maybe that’s not entirely true, but you get the point. A well maintained exhaust will perform better, last longer and even look better too! Here are a few things to keep up on:
• Exhaust plug: (Yes, we know what they are also referred to, but to keep the lawyers happy…):These little guys insert into the end of your exhaust and keep water out when washing. Not only does this keep water from getting into the engine, but keeps the packing lasting longer.
• Clean: keeping up on cleaning your exhaust will save you hours in the long run, especially if you have a factory finish pipe. If you do, coat the pipe with a good amount of WD-40 after each wash, and scrub any rust off with an S.O.S. pad or steel wool.
• Repack: It’s wise to repack that silencer or muffler regularly. We don’t recommend this just because of the obnoxious sound emitting from your bike, but because packing actually helps the performance of your exhaust. Packing is cheap, easy to replace and adds power. Win-win…win!
Hopefully we’ve managed to help you along your exhausting (sorry, we just had to…) journey to find the right pipe or muffler for your dirt bike. As always, give our customer service members a call if you have any more questions about what exhaust options are best for your budget, bike and riding style.