2010 Exhaust Pipe Buyer’s Guide – Dirt Rider Magazine

There are many reasons a dirt rider would be shopping for a new exhaust pipe. Some are searching for more power; in our opinion smarter riders are looking for more effective power. Those a little higher up the intelligence scale are looking to make their machines legal for where they ride. The truly enlightened seek sound reduction. We hate to look too closely at the impulses that lead most of us to simply appreciate a new exhaust because it looks cool, but even the most anti-bling among us is susceptible. Although we sincerely hope they are becoming extinct, there are those who still think louder is better and desirable. Regardless, pipes are a common and important buying decision.This is more than your normal listing of products. We asked each manufacturer to supply a pipe that was representative of its lineup. We could have asked for every pipe made for one or two bikes, but what if you don’t own that bike? In our experience each company has general uniformity in its design and testing, and therefore performance trends are similar across multiple bikes. So, if you get a pipe from a company for a Kawasaki KX250F and a pipe for a Honda CRF450R from the same company, both pipes will usually have a similar effect on power. We asked the companies to pick the bike it wanted to have tested. The categories were four-stroke MX, four-stroke off-road, two-stroke MX, two-stroke off-road and playbike. In cases where there are pipes that are distinctly different in performance, we allowed each type to be submitted. That meant that full-line companies like FMF and Pro Circuit had more products tested. We tested every pipe at multiple locations. Each unit was carefully weighed on a certified postal scale. Finally, at the conclusion of our comprehensive exhaust system test, we had sound expert Chris Real from DPS Technical/Chem-Help sound test each and every combination.In this test we opted not to cater to the group of riders who want a louder pipe. We set sound parameters for the popular SAE 20-inch test used universally in enforcement as well as the new FIM full-throttle test measured from two meters. For the 20-inch test we specified 96 decibels as the max for off-road and 99 decibels for motocross, since those are the current standards. For the full-throttle test we stipulated less than 115 decibels for off-road and below 120 decibels for MX. Also included was a third-gear roll-on wide-open test measured at 100 feet for a real-world riding comparison of the sound data for you (and us) to look at. We specified stock jetting on all models for the test for consistency. In most cases that worked out fine, on some of the non-MX bikes lean jetting (popping, sputtering at test rpm) had a negative effect on sound numbers. We were pleased that only one pipe missed the MX standards for the static test and all passed the full-throttle test. The majority were actually quieter at full throttle than stock MX mufflers. So digest the information and find what companies will be best for you…even if you are planning on buying the one that just plain looks cool or is on your favorite factory rider’s bike.AKRAPOVIC

2010 Honda CRF250R Evolution Ti System
Price: $1,226.95
Weight: 5.55 lbThey said: The Evolution complete exhaust system is the championship-winning flagship of our product lines. It is made of our exclusive and durable high-grade titanium. With the quality, performance improvements, weight reduction and modern muffler design, it will satisfy even top pros. Power increase is spread throughout the entire rpm range with the biggest increase in the bottom and on the top of the range. Maximum increased power of 3.9 horsepower was measured at 5600 rpm.

We said: The best thing about this pipe is that it makes the power very consistent and predictable, which is great for not upsetting the bike. Some riders felt that this pipe pulled better than any of the CRF250R pipes way down low, and most felt a boost in high rpm power. For anyone intimidated by a 250F, who rides in slick conditions, who just loves smooth power delivery or who lacks throttle control finesse, this is a good choice. The pipe just looks great and oozes quality construction.2010 Suzuki RMX450Z Racing Ti/Stainless Full System
Price: $888.95
Weight: 7.55 lbThey said: The Racing complete exhaust system is designed for competition-oriented enduro riders who demand maximum performance from their exhaust systems. It’s made of extremely durable stainless steel tubing-we use titanium for the muffler’s outer sleeve-and has an approved spark arrester. The system increases power and torque through the entire rpm range. A maximum power increase of 5.1 horsepower was measured at 7730 rpm, while peak power of 44 horses was measured at 8200 rpm.We said: This system made a big boost in power everywhere and made the bike much more ridable. It gives it a lot more torque on the bottom, and you don’t have to be revving as much (or turning the throttle as far) for the same amount of power as you do with the stock exhaust. It especially livens up the pickup in the middle as well as making more power everywhere. Decent sound compared to almost any other pipe, but compared to stock it is loud.The Scoop: Akrapovic is a high-quality, state-of-the-art European factory that makes its own titanium tubing. The company makes exhaust systems that are near museum quality. The prices reflect the workmanship and the poor U.S. dollar/Euro exchange rate. Akro pipes offer excellent performance with reasonable and responsible sound output.Contact: www.parts-unlimited.com, see your dealer; www.akrapovic.com

2010 EXHAUST PIPE BUYER’S GUIDE

Sound Off

2009/2010 Honda CRF450R S7 Boost System
Price: $699.00
Weight: 7.65 lbThey said: New and improved in 2010, the DEP S7 silencer with Boost headpipe for the CRF450 is designed to increase power and torque over the entire range of the pipe. While the Boost header increases torque and reduces noise, the S7 silencer increases peak horsepower with its improved bleed chamber.We said: This system was surprising. It smooths the CRF’s power output without restricting it. It would be the best system for off-road use as it really showcases the torque of the motor. It doesn’t jump out with a powerful feeling anyplace, but really gives the bike great throttle control and response with minimal unwanted snap. The power was gapless and seamless, lasting a long time in every gear. It has that long header pipe feel. It’s a great GP-style pipe for riders looking to spread the CRF’s punch. Also, riders coming off 250Fs that would rather carry smooth momentum than stop-and-go will dig the way this system delivers good power without upsetting the chassis’ balance/ride. Plus, the DEP is quiet to those near the track but sounds really good to the rider.2005-2010 Yamaha YZ125 Torque Pipe
And Round Silencer
Price: Pipe $255.00, silencer $111.00
Weight: 5.20 lbThey said: DEP’s new YZ125/144 Torque system is designed to increase torque in the bottom-end and increase horsepower throughout the range. It was designed primarily with the YZ144 in mind, although it does fit and improve performance on both displacements.

We said: Compared to stock, this exhaust felt like it loosened up the engine and allowed it to rev freer, which made the bike rev through the power faster. This brought the bike’s shift points earlier, and sometimes required an extra shift over stock. The faster rev was great for throttle response, making the bike even more “two-stroke-y,” if that’s possible. It was a smooth delivery so it was easy to control, just a faster rev.2005-2010 Yamaha YZ125 Rev Pipe And Round Silencer
Price: Pipe $255.00 in raw finish, $276.00 for plated, silencer $111.00
Weight: 5.25 lbThey said: The new DEP YZ125 Rev system is designed to increase peak horsepower starting in the midrange and increasing heavily through the top of the power range with solid overrev.We said: Our regular guys felt this pipe/silencer pairing hurt the low-end and gave the power a somewhat pipey sort of feel. It doesn’t come on with a jolt, there’s just not much power until it comes on. Once going, the power feels a little stronger with a strong sense of surge from the engine, without the too-fast-rev of the torque pipe. The pipe didn’t have the response when finessing the throttle compared to the stock or torque setups. The Rev worked if ridden with the throttle opened wide and charging all the time. Our fast guys felt the engine definitely wanted jetting and possibly race gas to prevent detonation with this pipe, but they liked the “power forever on top.”The Scoop: DEP is an established name in Europe, and has been involved with teams at the highest levels of the GP circuit. It is not as well-known as some other pipe companies, but it makes a good product. For U.S. riders the four-stroke pipes seem universally liked, but the two-stroke offerings seemed more targeted to power preference.Contact: www.deppipesusa.com; 302.337.3285ENDURO ENGINEERING

KTM 250/300 E3 Exhaust Pipe And E3 Silencer/Spark Arrestor
Price: Pipe $219.95, silencer/SA $149.95
Weight: Pipe 4.45 lb, muffler 3.10 lbThey said: Our pipe works great on the 300 XC-W, we sell more to off-road guys than MX guys. This pipe will work for moto, and for old guys it smooths the power out. With that being said, our pipe would work best for the 300 XC-W off-road bike.We said: While many of the manufacturer claims are a little inflated, the Enduro Engineering guys’ were the opposite. We found the pipe better than claimed and better than expected. This pipe/muffler combo was really impressive, especially on the 250cc bike. It was as though the bike got energized, like going from a weak battery to a full charge. All the while it had incredible, better-than-stock torque and snap, with response that is one to one with your wrist on the throttle. The results were similar, yet not as stunning on the 300. One of the best two-stroke pipe bolt-ons we’ve tried in a while. Only complaint: Just a bit easier to dent than some others.The Scoop: Enduro Engineering makes one pipe and one silencer, but both are for a bike that owner Alan Randt has spent years riding, testing and modifying. We’ve come to expect innovation and quality from EE, and that carries over to the exhaust portion of the company.Contact: www.enduroeng.com; 517.393.2421DEVIL EXHAUST

2010 Yamaha YZ450F Sprinter Carbone System
Price: $949.00
Weight: 6.90 lbThey said: Devil exhausts are designed for amazing power gain and the top level of off-road competition, and are the ultimate step to factory performance. Much of the pipe is titanium, with a reinforced carbon sleeve for weight.

We said: This pipe looked a little complex with the unique chamber, but it mounted easily. It gives the bike more bottom before the stock hit and fills in right after so it is meatier and more chugable. Then, it feels like it adds a little bit of power all the way to the top with a little more overrev. There is definitely more overrev than stock, but not more power feel on top. This style of power seems consistent with other Devil exhausts we’ve tested. There were also big pops on decel every once in a while. Our pipe is burning through the carbon on the front of the muffler, despite the fact the parts are tested to 1500 degrees. The pipe is covered against failures of this sort for one year.KTM 400/450 XC-W/EXC 6Days Stainless Steel System
Price: $699.00
Weight: 10.40 lbThey said: Enduro racing is the most hard-core category for hardware and machines. Devil has created the perfect match to the extreme conditions and performance requests of the best World Enduro riders. The result is the Devil 6Days full system. Built in stainless steel to resist the worst race conditions, Devil offers you factory-level equipment for the most dramatic performance upgrades yet meets the most restrictive sound rules.We said: Mounting this pipe for the first time is tedious. As you would expect for a large, heavy muffler with a small outlet opening, It was quieter than stock. Power is more energetic. It is smooth and soft for technical down low, but snaps to life with authority with the clutch, and it actually hits the rev-limiter under load. It gave a better boost to mid and top rpm power than expected, the steer-with-the-rear mid-hit is still there in good quantity, but some faster riders felt the delivery might be too smooth, though the top is still very strong. The spacers between the pipe mount clamps and the subframe are pretty long, and the supplied bolts are only 6mm. On the third ride both of the mounting bolts on the can broke off leaving the threaded ends in the subframe. Devil sent new bolts, and we haven’t had another problem.The Scoop: Devil is another company that is established in Europe, but it is even newer in the U.S. than other Euro brands. The Devil MX system was light and performed well. The 6Days off-road system is the heaviest in the test but was also one of the quietest, yet it still performed exceptionally for a quiet system.Contact: www.devil-exhaust.com; 877.389.8518DR. D

KTM 400/450 XC-W Slip-On
Price: $409.99
Weight: 5.30 lbThey said: Unequalled testing, unmatched performance. DR.D exhausts endure countless “seat time” hours before receiving the Doug Dubach production stamp of approval. It’s easy to produce exhausts when the goal is a peak horsepower number on the dyno. DR.D exhausts are the result of Dubach’s 25-year factory racing/testing career. With WORCS racers Mark Tilley’s and Dustin Nelson’s involvement, Dubach and crew built a broad, strong power-character exhaust riding in the same harsh environments as KTM owners do.We said: This is a really nice-fitting pipe with exemplary hardware. Performance is excellent across the rpm range with nice off-idle chug, an active mid and a raging high-rpm pull. Getting the front wheel up is easy, and the bike revs until it gets that odd, “almost-a-twin” sound that Yamaha YZ250Fs get. The acceleration feels almost motocross snappy. Sound is definitely up compared with stock, and it is right on the razor’s edge of the 96 dBA limit.2010 Yamaha YZ450F Aluminum/Stainless System
Price: $649.99
Weight: 7.20 lbThey said: Does anyone have more testing seat time on YZs than Doug Dubach? At the forefront of YZ development for decades, Dubach uses his passion and testing experience to build unequalled exhausts. DR.D was the first company to build the unique curled exhaust, and the performance of the DR.D system tells the tale of a man who develops and races for a living. When you’re the owner racing with the exhausts you build, you build the best.

We said: This pipe either smoothed the power delivery and took a bit of the snap away (in a good way) or gave the bike more snap depending on where the rider liked keeping the rpm. It still let the bike rev further than stock when you wanted to hold a gear longer. It has a good, healthy mid-bottom punch. Something that is good if you’re the type of rider who likes to make big gains in the start of a straight. This delivery is unsettling to some as they’d try to get on the gas early in corners, where the bike would be making a ton of power compared to stock. Decent sound but has that DR.D bark or high-pitched sharp snap to it that is a little much for the sound-conscious. Install bound up a bit since the Tornado system requires more maneuvering.The Scoop: DR.D’s main man Doug Dubach is a legendary racer with a pro career spanning 30 years and has nearly as many years as a development and test rider. He was highly instrumental in developing the Yamaha four-strokes. He uses that wealth of experience to produce pipes that usually work very well in the real world, but the DR.D lineup could still tone the sound down just a bit.Contact: www.dubachracing.com; 877.382.2241FMF RACING

2008-2010 KTM 250/300 Fatty 2-Stroke Off-Road
Price: Fatty $229.99, TurbineCore 2 $149.99, Q $159.99, Q Stealth $179.99
Weight: Fatty 4.90 lb, TurbineCore 2 2.90 lb, Q 3.45 lb, Q Stealth 3.90 lbThey said: The Fatty for the KTM was actually developed by multiple-time World Enduro and GNCC champion Juha Salminen. Juha kept testing until we came up with a pipe that produced massive gains but maintained flawless delivery from the bottom all the way to the top. Off-road riders need power that allows them to run in higher gears in order to get traction, yet at the same time have plenty of power and response when needed.We said: This one has more pronounced hit on the bottom, smooth through the middle and then revs flat on top without a big overrev. FMF pipe performance is heavily influenced by the muffler choice. The TurbineCore 2 is the snappiest of the off-road mufflers and really works more like an MX muffler in comparison. It helps amplify any snap the pipe gives and also revs out quicker through the power being flatter on top. With the longer Q muffler the Fatty feels like it doesn’t lose any snap, but it spreads out the power the farther you rev the bike, and then makes the top-end long and usable. The Q is a better match for the Gnarly. The larger can of the Q Stealth makes the exhaust the quietest to the rider. It also dampens the snap maybe just a bit too much for some, but for a true trail hound, this is great for traction. It then continues the trend of smoothing, slowing the rate of rpm increase all the way to the top where it pulls longer and perhaps harder than any of the other mufflers. It makes torque, not horsepower, though you can get any snap lost back with the clutch because it is only smooth, not lazy.2008-2010 KTM 250/300 Gnarly
Price: Gnarly $229.99, TurbineCore 2 $149.99, Q $159.99, Q Stealth $179.99
Weight: Gnarly 5.45 lb, TurbineCore 2 2.90 lb, Q 3.45 lb, Q Stealth 3.90 lbThey said: The FMF Gnarly and Q Stealth together give a smooth, strong, healthy pull from the extra boost on the bottom, and a sweet, healthy note. The Q Stealth “spark arrestor-approved” will put you in the 89 db to 92 db range. The extra volume and packing in the muffler extends the life between repacking.We said: The Gnarly pipe seems to smooth the power except on the bottom where it gives the bike a little pop or snap right at idle. Then it feels like it takes a little longer for the powervalve to pick up, a later surge of power where it is longer and flatter on top but with overrev. The pipe is heavily influenced by the muffler choice. Some riders feel this pipe is the better at climbing back on the power if it does fall off compared to the Fatty.

2005-2010 Yamaha YZ250 Fatty 2-Stroke MX
Price: Fatty $229.99, Powercore 2 Shorty $119.99, TurbineCore 2 $149.99
Weight: Fatty 5.00 lb, Powercore 2 Shorty 2.05 lb, TurbineCore 2 2.90 lbThey said: The Fatty differs significantly from the Gnarly. The Fatty is a hard-hitting pipe in the mid, then pulls like crazy to the top! To help launch you up over any obstacle on the track! The Powercore 2 Shorty makes it even snappier, more crisp sounding and more responsive for SX, MX or faster off-road-style events!We said: Installation caused no issues, stock-type O-rings are supplied, and it featured a perfect fit. The Fatty pipe/Shorty muffler combo broadened power through the YZ’s rpm range while giving it an excellent sound. It was slightly soft off the bottom, but the great mid/top pull makes up for the lack down low. The pipe makes a great transition into the powerband. It pulls higher, lugs better when off the pipe (different than starting into the revs, where it is slightly soft as mentioned above). This pipe makes great power when not rapped out. Only our pro tester wanted a harder hit. When using the Fatty with the TurbineCore 2 the bike revved slower and extended the top/overrev. The midrange was more linear than with the Shorty. Other pluses are that the bike is quieter, sounds better-more throaty, less raspy. So surprisingly, we felt the best combo for MX was the Fatty with the TurbineCore!2005-2010 Yamaha YZ250 Gnarly 2-Stroke MX
Price: Gnarly $229.99, Powercore 2 Shorty $119.99, TurbineCore 2 $149.99
Weight: Gnarly 5.70 lb, Powercore 2 Shorty 2.05 lb, TurbineCore 2 2.90 lbThey said: The Gnarly for the Yamaha YZ250 does what it’s named after: Makes it Gnarly! Focused toward strong low-end with meaty midrange providing more torque which allows you run in higher gears for increased tractability for any type of riding. Eighteen-gauge carbon steel makes it more damage-resistant for the off-road environment! The TurbineCore 2 comes with a USFS spark arrestor, but performs close to a moto silencer to create even smoother, stronger power.We said: The Gnarly pipe had a slightly tight fit but still no problem, and O-rings are supplied. As tested with FMF’s TurbineCore 2 this pipe gives the YZ250 way gnarlier grunt with more bark and hit on the bottom with a throaty sound. It runs a bit flatter on top, but when short-shifted and kept in the power it was fine. For our guys it is more of an SX/turn-track pipe. Mounting the Powercore 2 Shorty narrowed the power down and shortened the spread, especially on top. It still had hit, but then truthfully made more noise than power. For some riders this power was perfect as they could either under-ride or over-ride the power without having too much and the hit made them feel more power.2006-2009 Honda CRF450X Q4/Stainless MegaBomb Header 4-Stroke Off-Road
Price: Q4 $359.99, stainless MegaBomb $274.99
Weight: 7.95 lbThey said: The Q4 (unplugs and adds power) employs intricate chambers and baffles, and together with MegaBomb technology (adds more snap and response) makes the CRF450X more powerful and responsive through the entire range of the powerband. It makes the bike more fun to ride, and you feel the power! Comes standard with a USFS-approved spark arrestor and is usually under 93 db.We said: The stock CRF450X is a quality trail tool, but it feels more appliance than entertainment. The Q slip-on instantly tripled the fun factor. The installation is easy; the sound goes up a hair but is totally reasonable. Jetting is lean stock, and even a bit leaner with the Q. (We tested all bikes with stock jetting, and on the CRF-X this affected the static sound test negatively.) Add the MegaBomb and the bike gets more dial-a-wheelie tug in the lower mid and on up. This combo is quiet to the ear and a favorite in terms of performance. It didn’t have the sheer hit of the loud models but carbureted the best of the aftermarket systems with stock jetting.

2010 Honda CRF250R 4.1 Muffler/Stainless PowerBomb/Stainless MegaBomb 4-Stroke MX
Price: 4.1 slip-on $449.99, stainless PowerBomb $199.99, stainless MegaBomb $274.99
Weight: 4.1 with PowerBomb 6.2 lb, 4.1 with MegaBomb 6.55 lbThey said: Stainless 4.1 mufflers come with a titanium canister. Resonance Chamber Technology (standard on the CRF250R model) increases power across the rpm range. The 4.1 combined with an FMF header will enhance the power even more. The MegaBomb makes the CRF250R responsive and crisp, which makes it a great supercross setup! The PowerBomb makes the CRF snappier, has a strong bottom but really starts cranking into the mid to the top with extra overrev!We said: There was no disputing that the 4.1 muffler system was a favorite of riders at all skill levels with comments that the power felt more immediate and on-tap than other combinations. But FMF has two headers, and opinions were strong and varied there. Some felt the MegaBomb amplifies stock delivery everywhere with a bit of ferociousness thrown in at all rpm, and others found it just a bit too responsive at the lower rpm, since it tended to light up just a bit too quick. Riders without a pro’s cornering speed found the MegaBomb helped them clear jumps the easiest. Both headers make the most difference below half-throttle, but the PowerBomb was amplified over stock everywhere like the FI got tuned snappier and more responsive but not too much. It worked in all traction conditions and seemed quieter than stock.2006-2010 Honda CRF150F Q4 Playbike Slip-On
Price: $289.99
Weight: 4.05 lbThey said: The FMF Q4 muffler adds power and response everywhere in the rpm range, but it remains extremely sound responsible. Playbikes like the 150F see use near homes and around the campsites, so they need to stay quiet. Pounds lighter than stock and made from aircraft-grade aluminum and high-strength stainless, make this puppy super durable!We said: The CRF150F and most playbikes are pretty mildly tuned, and they don’t run or carburete properly with a loud, open exhaust. The FMF Q4 is a quality pipe that is lighter, tucked in better, looks great and works awesomely. It ran well with stock jetting. The engine takes a little longer to warm up but responds quicker, revs easier and runs a little harder and zippier everywhere in the rpm range. At the same time it remains easy on the ears. Installation is a snap, and the pipe is very solidly mounted.The Scoop: FMF has an amazing manufacturing facility to make its high-quality exhaust systems. All of the pipes make noticeable gains and work as advertised. It even fabricates its own titanium tubing and stamps all the end-caps. All of the pipes are dyno and track tested to make sure the products perform. FMF remains dedicated to quiet pipes, and especially off-road systems and gives back to the sport with various programs. While other companies barely have spark-arrested pipes, FMF has a variety.Contact: www.fmfracing.com; 310.631.4363HRC

2010 Honda CRF250R Titanium/Carbon Fiber Full System
Price: $1,999.95
Weight: 4.40 lbThey said: This pipe is made with the same care and exotic materials HRC would lavish on a works bike. Performance is about the same as stock, but the pipe is lighter than stock.We said: This was another pipe that was “underclaimed.” The performance is supposed to mirror stock in a lighter package. It is a fabulous-looking system and as light as claimed, though that craftsmanship and weight come at a price. Most felt the torque was boosted at all rpm with just as much overrev as stock-which is great. Carbon fiber pipes are notoriously short-lived, but the HRC is holding up well to our abuse.The Scoop: This was the lightest four-stroke complete system in the test. It is a work of art, and obviously built to an amazing standard. The acronym HRC are the Holy Grail at the factory level in Japan, and this is your chance to own a piece of it for a price.Contact: See your Honda dealer

HMF RACING

2008-2010 KTM 450 XC-W/EXC Performance Series
Price: $259.95
Weight: 6.50 lbThey said: HMF Competition Series exhausts feature three levels of power and sound, allowing you to dictate the type of power and sound you need, when you need it. Included with every exhaust are three removable inserts, each of which affect the sound and power in different ways, giving the rider complete control. Choose from several finishes for the aluminum canister.We said: HMF came late to the party, and sent two easy-to-install sound inserts, but for the test we asked them to decide on one insert, they chose the most restrictive tip. The pipe installs fine with all needed hardware. It sounds like stock or a little quieter. High-rpm boost is strong, and the power is super smooth down low. The transition to mid-hit is smoother or softer, then picked up in the upper midrange or when the throttle was yanked. Especially good since it toned the motor a bit softer compared to the stock delivery but kept all the top pull and stayed quiet at high rpm where the stock pipe gets loud. This pipe is somewhat ordinary looking, but a good performance value for the money,The Scoop: HMF is an established exhaust manufacturer with a full range of ATV products, but the company is branching out into two wheels. The products are reasonably priced, perform well and are very sound-tunable.Contact: www.hmfracing.com; 216.631.6980JARDINE PERFORMANCE PRODUCTS

2006-2009 Honda CRF450X RT99
Price: $590.00
Weight: 7.45 lbThey said: The RT99 is designed for our amateur and everyday racers. It will easily pass the AMA standard for amateur off-road racing, at 99 decibels. A Resonance Chamber on the headpipe helps reduce sound levels and increases power across the rpm range, with an emphasis on bottom-end torque.We said: The Jardine mounts up without much trouble, but must use the Jardine header. The Helmholtz resonator chamber makes the header a little easy to burn pants on. It made the stock jetting lean enough to be a problem. It not only runs funny and feels very lean, but the bike is spitting, popping and banging at low rpm. The bike barely missed the sound cut-off (with plus or minus 1.5 db included), but we didn’t fail it. If jetted cleanly, it would easily pass. Jardine makes some quiet tips, and this pipe should come with a quiet one. On the plus side, this pipe makes a lot of power. It makes the CRF-X feel like a moto bike, but the jetting weaknesses and the sound are an issue. This pipe isn’t great for technical trails but is very good in anything fast enough to have some flow to the terrain.The Scoop: Jardine has a long history in the exhaust business starting with cars, but with a presence in off-road motorcycles coming more recently. The systems are well-made, built tough actually, with a unique look. The only failing is that they are a bit loud when compared to similar pipes on the market.Contact: www.jardineproducts.com; 951.739.5900LEO VINCE

2010 Honda CRF250R X3 Complete Titanium System
Price: $1,149.00
Weight: 5.85 lbThey said: The Leo Vince X3 Motocross/Supermoto full systems define the high technological levels that can be achieved in the design and construction of motocross exhausts. Both the header pipe and the silencer are made entirely of CP1 titanium (the highest grade available) and are chamber welded in order to guarantee a reduced weight, improved balance and the highest level of durability. For 2010, the X3-94 Titanium motocross full systems test at 94 db or less.We said: Trackside this pipe sounded great-very quiet without any annoying raspiness to the tone. On the track it demonstrated a smooth nature and slow rev. The good side of this pipe is that it seems to stretch the revs. The power doesn’t get a “tapering off” feeling even when riding a section at a constant throttle opening. A good way to describe this pipe would be trading some of the stock pipe’s responsiveness for some meatier power. This pipe might be too smooth for most, especially if you want the pipe to make snap.

The Scoop: Like many of the European pipe companies, the fit and finish of Leo Vince products is very nice. Generally these pipes are exceptionally sound responsible as well. We’ve had excellent recent durability and performance results with a variety of Leo Vince pipes including the KX250F, KLX450F, XR650R and CRF450R. In general the pipes offer smooth, torquey power, plenty of energy in the middle and clean top-end pull.Contact: www.leovinceusa.com; 510.232.4040PRO CIRCUIT RACING

KTM 250/300 Platinum Pipe And Type 296 Silencer 2-Stroke Off-Road
Price: Platinum $241.95, Type 296 spark arrestor $159.95
Weight: Pipe 5.56 lb, Type 296 3.85 lbThey said: The Platinum pipe has the same shape as the popular Works pipe, but utilizes plating to protect it from everyday elements. The Platinum pipe is a fusion of power, elegance and utility. The Type 296 spark arrestor is specially engineered with an internal metal baffle, chambers and sound-absorbing materials for a muffled exhaust sound and no loss of motor performance. The sound level is at or near 96 db on most models.We said: The combination of the Platinum pipe with the 296 spark arrestor installed passed sound easily enough. The pipe has a smooth roll-on, and chugs along as good as any on the bottom, but snaps to life harder and a little later than most of the KTM pipes do. When it hits and pulls, the PC pipe really makes the 300 rip, so it is fun. This pipe is a good bet for riding that is a little faster and more open.2005-2010 Yamaha YZ250 Platinum Pipe And R304 Silencer 2-Stroke MX
Price: Platinum $229.95, R304 $119.95
Weight: Pipe 5.25 lb, R304 2.00 lbThey said: The R304 silencer’s short aluminum canister offers optimum performance gains and is recommended for closed-course racing only. The Platinum pipe has the same shape as the popular Works pipe, but utilizes plating on the body. The Platinum pipe is a unique fusion of power, elegance and utility that pushes the boundaries of the sport’s riding pleasure.We said: Installation of the Platinum pipe is fairly painless, except Pro Circuit didn’t include an O-ring where the pipe meets the cylinder. You need to make sure the shorter bolt goes where the kickstarter is or it will bottom out on the pipe. This pipe and silencer really woke up the bottom and mid of the YZ, but it kept it usable and smooth with good transitions throughout. Up top, the bike didn’t sign off as abruptly as stock but didn’t pull any longer, just had a cleaner feel. Same sound output as stock, with a barky character.Honda CRF150R T4S Slip-On Playbike
Price: $464.95
Weight: 5.20 lbThey said: The T4S slip-on has an impressive design, polished aluminum canister, stainless steel mid-pipe and ultra-responsive performance. Setting an affordable standard of riding excitement, the T4 Slip-On is developed to increase the horsepower and torque throughout the power curve. The pipe comes with a spark arrestor installed, an insert to replace the SA and new packing material for the first rebuild.We said: The Honda CRF150R has a great small-bore engine, but the response off idle is finicky with a lean-bog feeling. The T4S slip-on is a little longer than the stock muffler, and is in fact long enough that our boots scratched the artwork on the canister in short order, but it solves the bottom-end response issues, smooths the mid-hit a bit and aids the high-rpm urge a little. All this plus effortless mounting and a significant 6 db reduction in full-throttle sound output. The T4S is a nice addition, doing everything a quality exhaust system should do.2010 Honda CRF250R T4 GP 4-Stroke Off-Road
Price: $779.95
Weight: 6.70 lb

They said: The pipe comes with a spark arrestor installed, an insert to replace the SA and new packing material for the first rebuild. Styled after the Ti-4 GP system the T4 GP system offers the same great performance without the expense of titanium. It’s designed to increase performance from bottom to top-end, making it easier to ride faster. The T4 GP system saves weight over most OEM systems, and it complies with AMA sound restrictions.We said: As delivered this is an off-road/spark arrestor-type system, and was tested in that context on moto tracks. It acts just like you’d expect with a nice, calm delivery down low and most of the power improvement coming on up top and the last third of the rpm getting there. It has excellent control, a smooth “carburetion” feel while mirroring the stock delivery of the 250R nicely. Sound quality (especially to the rider) is improved for most. Fit and finish is top-notch with no hassles or confusing hardware. As a GP-type course race system, the PC unit is solid and we suspect snappier gains for moto are a spark arrestor screen removal away.2009-2010 Honda CRF450R Ti4R Race System
Price: $999.95
Weight: 5.84 lbThey said: The all-new Ti4R Race system is strictly for closed-course competition. This is identical in design to the Ti4R system used by Team Pro Circuit as well as factory Kawasaki and factory Suzuki. It comes with packing material for the first rebuild.We said: This system does an amazing job of making a lot of people happy. Smoothness is improved with enhanced power and better overrev than stock. Not as much unwanted snap of the stock system but it is still on demand. More power and smoother delivery are hard to mate, but PC does that here and sound is on par with stock. A very cool hot-rod sound that says, “I’m making power.” Rather than saying, “I’m a poorly engineered noise can that makes you think I’m making power.”The Scoop: With multiple offerings in the two- and four-stroke arenas, Pro Circuit has the exhaust biz covered. Typically they make the snappier end of the two-stroke pipes and the smoother of the four-stroke pipes on the market, all with power gains. You may think of Pro Circuit as a race team, and with decades of championship-winning efforts it is, but it all started with engine modifications and pipes. Pro Circuit products run the gamut of price, sound and materials.Contact: www.procircuit.com; 951.738.8050TWO BROTHERS RACING

2010 Yamaha YZ250F Slip-On System With M2R Carbon Fiber Canister
Price: $599.98
Weight: 5.05 lbThey said: This product is designed and built with painstaking care and attention to detail. It has increased throttle response with more power in the midrange and a smooth delivery while meeting the motocross sound limit of 99 db.We said: The X-Lite ring allows the headpipe to spin on the muffler, so alignment is a piece of cake. Super-detailed instructions (with photos!) and hardware provided made installation a snap. Off idle, the Two Brothers exhaust provided better response and improved bottom-end pickup, just what the YZ-F needs, along with making the bike rev more quickly. It makes the power more consistent, though. The livened-up power allows the rider to stay off the clutch, but can spin the tire on slick spots. This slip-on helps to clean up the YZ250F, enhance its personality without radically altering the character and makes the bike quite a bit louder to the rider, but not as much to the sound meter.The Scoop: Two Brothers makes a quality product with excellent fit and finish and enough adjustment to handle a bike if a crash has rendered it less than factory straight. This new M2R muffler technology allows a user to repack the system in claimed minutes while the bike is still on the bike. We’re still using the stock packing but the system looks fast to service. The company goes for an overall improvement in performance, and it resists going for a big number or hit just to gain buzz. Add in the Two Brothers custom shop and you can get a fine-looking and performing pipe.

Contact: www.twobros.com; 800.211.27672009-2010 Honda CRF450R Ti-Pro Slip-On
Price: $499.00
Weight: 4.45 lbThey said: Created for a factory race team, the Ti-Pro slip-on was built to the meticulous standards only the top riders in the world demand. This system delivers the bottom hit your four-stroke machine craves and will continue to improve horsepower and torque throughout the rpm range. This mid-pipe and muffler design will significantly save weight over the stock system. Designed to meet the 94 db sound requirement. Factory racing team performance delivered to you.We said: This pipe produces an average change for what we have come to expect for a slip-on. It gave the bike a noticeable improvement in snap, at the same point where the stock muffler allows the bike to hit, just amplified. Then through the power it helped the bike rev a notable amount faster. It never makes the CRF feel more powerful, in the end revving out just a smidgen further than stock.The Scoop: Vance & Hines has decades of pipe experience, and it added to it when it absorbed the popular White Brothers brand for a dirt line. There is a full line of pipes, including four models for the CRF450R.Contact: www.vanceandhines.com; 562 921.7461YOSHIMURA

2006-2009 Honda CRF450X RS-2 Complete System
Price: $595.00
Weight: 8.95 lbThey said: This Full System comes with a stainless steel header and mid-pipe, aluminum muffler sleeve. Stainless Systems come with a 96 db sound insert/USFS-approved spark arrestor installed in the muffler. Optional 94 db and 99 db sound inserts available separately.We said: This is a nice product. It mounts fine, but takes a little more time than some simpler systems. The muffler will not work with the stock header. Jetting is lean as is the case with most systems for EPA bikes, and needs a specific setting to perform optimally. It passes sound fine but would be better with correct jetting. The power is snappy down low with a poppy, solid grunt right off idle and good pull as the revs climb. It feels and sounds like a race pipe. There is a lot of power on tap, but gives the 450X a little motocross-style power at the expense of the stock smooth and soft delivery.2008-2010 Suzuki RM-Z450 RS-4 Complete System
Price: $995.00
Weight: 6.20 lbThey said: As the official exhaust of the Rockstar Makita Suzuki Yoshimura supercross/motocross team, this exhaust was designed with one thing in mind, winning races. The RS-4 is a unique design with predicated power, a side benefit of a quiet, earthy exhaust note that speaks volumes for performance. This full system comes with a titanium header and mid-pipe, carbon muffler sleeve, installation hardware and detailed instructions to get you moving!We said: Instructions were good and the muffler is a solid fit. This exhaust livened up the power everywhere on the RM-Z, giving the bike a more aggressive character. Compared to stock, it puts more steps in the power and made the hits in the powerband more noticeable. There is more bottom, but the mid was the most noticeable improvement then it gave the bike a stronger top-end pull, making it feel like even more of a race bike. This exhaust really transformed the character of the machine, a tough task for an exhaust alone but this one does that. Not a huge difference in exhaust note or noise, the Yosh has a good tone.

The Scoop: Yoshimura has a bigger reputation in pavement racing than off-road, but the company lavishes the same care and technology on the off-road systems as it does on the roadrace units. Yoshimura has been a performance company for 55 years and has had a significant presence in the U.S. for roughly 40 years. The Yosh systems made the sound numbers, and the full system for off-road bikes is surprisingly affordable. Typically a Yosh pipe is on the snappier end of the power scale and you can feel a boost in power with every system we have tested from the company.Contact: www.yoshimura-rd.com; 909.628.4722