Vital MX Shootout: The Best Honda CRF450R Exhaust System 7

For many of us, a new exhaust is one of the most immediate upgrades we turn to after rolling a new bike off the showroom floor. Whether you're looking for more power, or to change the bike's character by moving the power around; you're trying to get a crisper or quieter sound, to lose some weight, or just bling it out...there's a lot to choose from.

In the case of the Honda CRF450R, the options really do vary, thanks to their dual systems and even the one that turns it back to a single. Now on its second year with the '17-18 generation model, we've had quite a bit of time to spend with a multitude of brands to find out which one we liked best, who's in the mix and which ones were just okay. So let's get into it with a quick round of the podium. After that, scroll down for more details like dyno numbers, weight, and in-depth comments on our top three picks, along with the other contenders in the Shootout.

First Place: Yoshimura RS-9T

What happens when you design your exhaust hand-in-hand with the HRC race team? Apparently some pretty great things considering it's in our top spot. From a unique design specifically for the CRF line, to competitive power, light weight, and ease of service...Yoshimura has a lot going for them.

Grab a RS-9T at MotoSport.com.

Second Place: Akrapovic Evolution

What can we say? Akrapovic exhausts are drool-worthy and getting your hands on one is kind of up there with kit suspension. From the quality to the price...they're high-end. It was a tight race at the top, but ultimately even the Akrapovic has its snags.

Shop for Akrapovic products at MotoSport.com.

Third Place: Pro Circuit T6

It's not the most glamorous in the test, but the Pro Circuit offers solid stats. It's surprisingly quiet for not being their "pro"-level system, it was easy to install, and offered an excellent spread of power.

Get a deal on Pro Circuit T6 systems at BTOsports.com.

How We Tested:

Most of the common brands had been on our '17, and later, our '18 CRF450R for extended amounts of time. As we accumulated more and more systems, we switched things up a bit. Each exhaust spent some alone time on our test bike, where we'd ride them for a day or two in different conditions. After making our way through each system, we snagged a couple of our regular test riders to assist in a back-to-back style test. In this case, we did three different days of rotating the exhausts for a few laps at a time at different tracks.

The back-to-back days revealed a lot about the differences in power characteristic of each pipe...along with how easy or difficult instillation of each set could be when in a rush. Finally, we also performed a quick dyno test and even a max RPM style sound test with each brand.

Our overall scoring was based off our opinions including power, price, sound, and fitment into our consideration. 

The Numbers

* Rocket Exhaust was unavailable on the day of group dyno and sound test.

** HGS titanium system isn't currently for sale in the USA, but BUD racing does offer their stainless/aluminum system.

Dyno tests were performed at Race Tech all on the same day, although the exhausts had slightly different ranges of use. Most were between the three- and six-hour mark when tested. The sound test was performed at Yoshimura, utilizing the same equipment that the FIM uses at Supercross, to the same parameters, which is the two meter/max RPM test. Many of the systems in the test have optional inserts, some included and some not. So in this case the sound test was done on each system as they're delivered to the consumer, since this is how the majority will run them.

Want to hear them all? Hit the video for clips from our sound test.

The Podium

First Place: Yoshimura RS-9T - Titanium/Carbon System

The Yoshimura RS-9T is the system for the newest generation CRF that we've had the longest, as it came out before 2017 CRF450R was even available to the public! Due to their long-standing relationship with HRC Honda, they had the opportunity to develop and test their system side-by-side with their race team.

Highlights:

• Head pipe, mid-sections, and exhaust cans constructed from titanium; exhaust can tip cover molded from carbon fiber.
• Developed alongside the HRC Honda team.
• Includes pipe spring puller.
• RS-9T utilizes six sections total; one head/split pipe, two mid pipes, two exhaust cans.
• Titanium system weight: 8 lbs., 3.9 oz.
• Titanium system MSRP: $1499.00

Initial Impressions

From the moment we pulled the RS-9T out of the box, you get that sense that it's pretty darn close to what Roczen and Seely use. In fact, we know the only real difference between them is an extra slip joint from the head to split section that HRC uses. This way the head pipe can be swapped in case of damage without replacing the Y section as well. Even with the production version being one piece from head to split, the Yoshimura comes in the most pieces of all for any system in this test. This includes two exhaust cans, two separate mid pipes, a head pipe/split section, and a flange/slip joint for the cylinder head. With this the whole system is very easy to line up, even with the mid pipe and can brackets using precise holes. Many of the other systems in this test have hollowed out brackets that allow them to fit even if they're a few millimeters off. On the other hand, Yoshimura has everything lined up quite precisely, leaving little room for error, and it still lines up perfectly. With all these sections, Yoshimura keeps everything a little more snug with a series of pipe springs for each major junction.

On the Track

Response is what really makes the Yoshimura a joy on the track. While the newest CRF has a lot more power overall than the past generation, it's still a bit mellow for roll-on power and pep when compared to say the KXF or YZF. The first thing we noticed when bolting up the RS-9T was a crisp feel over a wider RPM range, giving the CRF a bit more of a ready to go feel in all situations. This made it easier to seat bounce obstacles out of corners with a bit less clutch input, and to smoothly carry higher gears around corners, while still having that extra buzz to get rolling once out of the corner and  through the next section.

While the Yoshimura didn't have the most powerful roll-on power, or the most straight "hit" in the test, it was an excellent combination of both those things. It has the needed grunt down low, but still pulls into a nice hit as you get into the middle RPM range, and pulls very well to the top. With this good combination of gains, the Yoshimura stood out as a top choice across different conditions. While the Akrapovic was favored on the hardpack and pipes with big hit like the FMF dual were liked in the soft and sand, the Yoshimura was competitive and usable across the board.

When it comes to sound, the Yoshimura is crisp and sounds just like the ones you'll hear aboard the HRC bikes. Out of the box it squeaks in at the AMA max decibel test with standard/non-spark arrestor inserts. It sounds clean and runs clean at all RPM ranges and is overall very pleasing to the ears.

Fit, Finish, and Summary

How about the small details? As for the weight, it tied for the lightest dual titanium system. Price wise, Yoshimura allows retailers to sell at 10% under MSRP per their map pricing policy (making their systems and slip-on well-priced in their range). So subtract 10% from the ti price or jump down to a stainless system and you can still take that same percentage off. Also, due to the large amount of slip fit parts the exhaust doesn't negatively affect the rigidity of the bike. Lastly, the power was snappy, usable, and overall exciting; matching up with a tone that was also enjoyable but at the same time not ear-bleeding.

Yoshimura's options, fit, quality, and power output made for a solid victory in the eyes of our test riders. The group behind this placed this system all at or next to the top on their list when it came purely to power and usability on the power; and when the options, weight, availability and prices were brought into the fold it took the win.

Second Place: Akrapovic Evolution Line - Titanium/Carbon

I'm sure anyone reading this had drooled over the idea of getting their hands on an Akrapovic exhaust at least once and I that's what I was doing as I was unboxing it. The attention detail is immediately obvious; the construction is top-notch, the precise welds tug at your heart and they go an extra step with a lot of their hardware...including a very nice carbon heat shield for the headpipe and resonance chamber.

Highlights:

• Head pipe, mid sections/exhaust cans are constructed from in-house titanium.
• Exhaust cans are rubber-mounted, including grommets, cups, and hardware to install with their cans.
• Carbon fiber head pipe guard and hardware are included.
• Titanium system weight: 8 lbs., 4 oz.
• Titanium system (Evolution Line) MSRP: $1547.95

Initial Impressions

Drool, that was my initial impression. Not to say that the welds or production methods of other brands aren't up to snuff but the quality of an Akrapovic system is just another step up. Considering they have their own foundry, that means they control the materials involved with their own production, which is pretty cool. 

Akrapovic's Evolution line is their full titanium product and includes a bit more in the package than most systems. Inside you'll find a head pipe, resonance chamber and split section in one piece...along with a head pipe flange and exhaust port slip joint, and finally two exhaust cans with mid pipes built in. Also included are some extra parts, such as a carbon fiber guard which protects the headpipe and resonance chamber from side impact and your boot. Other than that there's the hardware needed for the guard, along with a full batch of pipe springs and rubber grommets/spacers for the exhaust cans, lastly a set of quieter/spark arrestor inserts.

With the amazing build quality of the system we expected the fit to be on point, but sadly it was a little bit of a let down. The slip flange and head pipe were perfect, but the problems came from the mid pipes mounts, which were too tight against the frame and would knock off the j-clips as you slid them into place. When placing the first side on (didn't matter if you started with the left or right) things were okay but the second side was very stubborn. Once things were forced on everything lined up perfect but then taking them apart was just as difficult as things were fit so snuggly, the first can was quite hard to remove. However, it was quite amazing how compact the design was, as the exhaust cans were barely even visible from behind the sideplates.

On the Track

Once out putting in laps, the Akrapovic was extremely impressive. Compared to other exhausts in the test, it had a big standout feature...serious pull down low. In our opinion this system had the best roll-on power in the group, offering serious torque from the crack of the throttle, but in a very controllable manner. From here the Akrapovic continues to pull well, but fairly conservatively compared to that initial hit. 

Now don't mistake that as saying it doesn't make power, it does, and plenty of it. It just does a great job of pulling consistently without any real dips or surges. Overall this gives the bike a feel like each gear is a bit longer, as it pulls long and through each gear quite well. The only real downside here is that it doesn't feel as exciting or snappy as some of the other systems out there, but it gets the job done and puts the power down.

As for the sound, ridiculously quiet when on the track. Now it doesn't sound muffled, it's just crisp and still fairly racey sounding, but not ear buzzing like a few others in here.

Fit, Finish, and Summary

As we've gone and on about...the quality, fit, and finish of this system was top-notch. Just considering the power output, it was close between this and the Yoshimura...but for different reasons. The Akrapovic stands out in the hardpack with the deep roll-on and usability, but the snappiness of the Yoshimura at a similar power level was quite good, too. For us, the price was a pleasant surprise. Yes, it's the most expensive in the test but during it we had this image in our head of what this system retails for the in the US that had us shaking in our boots. Considering the average Akrapovic titanium full-system is around $250-300 more than the competition, we were surprised to see their dual Honda system just a hair over other top-of-the-line options. In the end, the fit, plus availability of parts and service knocked the Akrapovic from competing with Yoshimura for the top step. 

Third Place: Pro Circuit T6 - Stainless/Aluminum

Pro Circuit is one of the biggest names in this test and offers quite a few options for the new CRF450R. We personally tested their stainless/aluminum system, while they make a titanium version and even a "Pro" option for their Ti6. The T6 and Ti6 are meant for the general public, while the Ti6 Pro is meant for...well, the pros. The main difference being the cans are longer and with different end caps for sound, so they aren't necessary for the average Joe. On the other hand, this system is priced several hundred dollars less than the cost of the two systems that finished ahead of it.

Features:

• Three-piece design; head pipe/Y joint, along with two separate exhaust/mid pipes.
• Head pipe, mid sections, and mid pipes made from stainless steel.
• Twin exhaust cans made from aluminum.
• Comes equipped with spark arrestors inserted.
• Made in the USA.
• Stainless system (T6) weight: 10 lbs., 15.6 oz.
• Stainless system MSRP: $927.00

First Impressions

From first glance the Pro Circuit T6 is simple, utilizing three parts with a head pipe to split, then two separate exhaust cans which have built in mid-pipes. This doesn't offer as much wiggle room for fitment, but luckily the mounts and bends involved seem to be on point, so installation was fairly simple. The overall look of the pipes isn't the most glamorous, with a plain headpipe, large mid pipe brackets and straight/slightly long cans that weren't the most appealing to our group of riders.

On the Track

After installation, we were quite impressed with the sound of the T6; the pitch sounding extremely crisp, while the overall output was low even while in the pits and equally quiet on the track. The T6 really gave it a clean, well-mapped sound that you normally hear on a race bike at a Supercross.

This led to a great on-track experience that just added a bit of power everywhere. The T6 was one of the easier pipes to carry a gear higher in corners as it produced excellent low-to-mid performance, rolling on with a deep grunt and building progressively through the mid-range. This doubled up with a power that was easy to roll-on but also very responsive to a little tap of the clutch when needed. After this excellent low-to-mid performance, it started to taper off a bit, but still pulled well. Overall, the Pro Circuit didn't stand out in any specific area compared to the other systems, but offered a solid bit of gains all over.

Fit, Finish, and Summary

Honestly, deciding whether the T6 would stand on our podium or not was hard. It was right in contention but ultimately the looks, size and the noticeable gain of weight over a stock system just cost it. The can size is a little on the long and bulky-looking side, which might sound nit-picky, but hey, we want our stuff to look cool too. Also, the stainless system we tested was actually heavier than stock version, on an already heavy bike.

Another note, we do wish that Pro Circuit would offer their stainless system with a carbon cap like their competitors, it would make us feel a little better about our stainless system as it would give it a higher-end look. But if you're a fan of the PC's style then by all means it's a solid choice; offering excellent all-around power, while being surprisingly quiet and offering a fairly sweet sound on the track.

The Other Contenders

Every system in the test made gains of some sort or another, so they each have their home and place. Keep scrolling to see who missed the podium and some words about each one.

FMF Single-Side Factory 4.1 RCT - Stainless/Titanium

Our initial impressions on the single-side FMF were mixed. While we know some users out there aren't fans of Honda's dual design, our group personally quite like the duals...especially when compared to the size and look of the single-sided FMF once onboard the bike. With the latest Honda's subframe design, mounting a single system has gotten quite hard so FMF resorted to an accessory bracket (included with the purchase) that mounts off the mid pipe and exhaust mounting of the subframe, then extends up to a bracket farther up on the can. 

This in itself isn't the most appealing option, but it has to be done for leverage and durability reasons. The nice part is FMF provides a smaller side-plate to replace the left side's wider plate that is no longer covering an exhaust. Installation is easy in the sense that you're only installing one can, but the extra bracket adds a bit of a headache, especially working the sideplate back on around some of the hardware on the bracket.

As for power, the FMF single was impressive when we got on the track. Loud, but fun! It offered a very healthy bark down low that was fairly crisp, making it easy to carry a gear high in corners while still having some pep to get up and go. From there it pulls strongly through the mid-range and tapers a bit at the top, but doesn't quite go flat. That makes it well-balanced and overall well-liked. The sound itself offered a nice sounding bark, but man, it's loud on the track.

Downsides were a little bigger than we'd like, and as we mentioned before the looks weren't doing it for us. Secondly, the price on the version we tested wasn't as cheap as we expected, as most stainless duals are within $100 or less and there's an option or two that's priced almost the same. Lastly was the handling, going from a good dual system to one large can actually does make a noticeable difference on handling and how the rear of the bike flexes. The first few laps on the bike we noticed a difference rolling into and out of corners, just enough that we caught ourselves adapting to it and making some riding position or throttle input changes.

For those that want to ditch the duals, you'll be happy with the power of this pipe but price-wise we'd recommend that standard stainless/aluminum system, as it's $100 cheaper than the stainless steel pipe and titanium can version we had.

Want to swap your CRF450R over to single life? Head over to BTOsports.com.

Bill's Pipes RE 13 - Stainless/Aluminum

A two-stroke pipe was my only prior experience with Bill's Pipes. While that was an enjoyable experience, I was unsure of what I'd find from their four-stroke product.

Fitment was top-notch on the RE 13. It features a simple design, with a rubber dampened mid pipe, and overall was on-point with dimensions to make it a breeze to install. The only complaint in this department was the head pipe flange, which folds easily when tightened down. It'll bend enough it'll barely come off the exhaust port studs. On the other hand, the overall system was quite compact...from a shorter head pipe design and exhaust cans to match that.

Power was fairly unique in the test, instead of adding a lot of punch it actually smoothed things out a bit for roll-on and then built consistently through the range at a good progressive rate. For the lack of a better term, I called this the "350 pipe" as it kind of reminded me of one. It's not flat initially, it's actually quite crisp, but just doesn't have the deep torque some of the others have, as it rolls into a very healthy mid-range and has the feel of a pipe that likes to run mid-to-top. This made the bike very rideable on hardpack, and fun to be aggressive with, but at times the lack of straight roll-on grunt did leave us wanting.

Overall, the fit, finish, and weight for a stainless system was quite good. Beyond that, the power was unique compared to many of the other pipes here, but it had its place and positive attributes. In the end, the look and price are fairly attractive, including offering a resonance chamber. The sound on the track is quite good and we were a bit surprised at how loud it rated on the meter test, as it didn't quite sound that loud when in use.

Shop for Bill's Pipes at MotoSport.com.

FMF Dual Factory 4.1 RCT - Titanium/Carbon

The FMF dual 4.1 RCT was one of the systems in our test we had the most experience with as we actually rode with it on both our '17 and '18 CRF450R test bikes. As with most FMF four-stroke systems, it keeps their signature can shape and blue titanium look, along with a Megabomb headpipe for good measure.

Starting off, the FMF was one of the easiest pipes to installs from a fitment standpoint, as there were only three pieces to assemble and ample room in the design to wiggle it into place, although the J-clips for the mid pipe mounts were a bit annoying as they would constantly fall out or get miss-positioned during assembly. While this was an easy fix each time, it was just a bit annoying.

Power-wise, the FMF sure is exciting, packing a heck of low-to-mid punch. This punch however wasn't the most well received for rideability amongst our riders. Interestingly, when we rode this package on our '17, while it wasn't the easiest to manage, it was still better than our '18. On our '18 model, there seemed to be a flat point at low RPMs, such as rolling through a tighter rut in third gear, and as you'd roll on the throttle you'd get some lag before everything came at you all at once. Even after spending some extended time with the dual FMF, it was hard to be consistent with it when things counted and made the power a bit more physically draining overall. Admittedly, this big hit was fun in soft berms and overall deep conditions but as soon as traction became a question, it was hard to manage and didn't equal for good laptimes...or the best riding experience.

Overall, the FMF does make a lot of power, just not the kind the riders were looking for. The sound itself was quite loud as well and the actual tone of the exhaust was the least liked in the test. It produces an unusual tone that just doesn't sound very crisp and really digs into the ears. Also, while their titanium full system price is on-par with other top-of-the-line systems, they don't have a good stainless dual option. FMF hasn't actually made an aluminum of their dual can for the tapered Honda design. Meaning their stainless head and mid pipe is still coupled to a titanium can. With this the price is $300-400 more expensive than their counterparts for a stainless dual.

If you choose the dual FMF system, we recommend using it on map one as it helps clean up the initial and hit a bit. Map three, which we preferred on most systems, compounded our complaints of the FMF's feel on the track.

If duals are your preference when it comes to FMF, check out BTOsports.com.

Rocket Exhaust - Stainless/Aluminum

Rocket's dual system was another item we have tested on both model years of the latest CRF450R, we spent a few laps with it on the '17, but it spent a little more time with our '18. Initially our feedback with it on the '18 was that it had a similar flat to large hit like the FMF, but didn't run as clean up top and didn't quite pulling through the end of the RPM range. It also featured a tad bit of backfire on deceleration. 

After our feedback, the crew went back to work and decided the mapping on the '18 was changed enough that they would develop their own engine map for the bike on the stock Honda ECU. Once finished, we spent a little more time with the system and ECU installed with great results. As you can imagine a bike that's mapped for an exhaust is quite crisp at all RPMs, giving it that little bit extra over the competition. With the ECU the bike has a lot cleaner initial power than before and rolls into that big hit entering the mid-range much better. It's still a bit much to take on in some situations but offers a big positive for someone looking for serious punch. From there it pulls cleanly and consistently through the top of the range.

Overall, the fit finish is middle of the road. We had a test system so it had some little hang-ups with fit around the electric starter, but that will be fixed for the final production run. The price is quit reasonable, along with Rocket offering the ECU flash we mentioned free of charge when ordering a full system, the only added cost is mailing your ECU to them, which they can send back separately or with the pipe when ordered. Without the ECU flash on the '18, we wouldn't rate this exhaust very far up the road, but with it, it's within our top three for performance. With the '17 ECU, the Rocket runs much cleaner and closer to how our '18 with a flashed ECU does. However, the fact that you have to send the ECU in is a positive/negative, and with the quite loud output it just slips it out of that podium area. Note: With the needed changes, this is the one pipe that wasn't available for our sound or dyno test.

To take a look through Rocket's options, head over to RocketExhaust.com.

HGS TC1 - Titanium/carbon

This was our first experience with a HGS product, and we were quite excited due to the numerous teams we've seen choose this brand across the MXGP and MX2 paddock. It's so uncommon in the US, it took us a minute to figure out where we were going to get it from. Luckily BUD USA, which is located in Southern California, is their main distributor and got their hands on a full titanium system to test.

Lets start with the good; the TC1 offers a big spread of power. It's not necessarily better than any other pipe in the test but overall it seems to add a bit everywhere and offer a solid package. It packs a decent punch down low and continues to pull consistently through the mid and to the top of the RPM range in the "seat of the pants" department and feels fairly crisp. The other notable positive was the sound...or lack thereof, as the HGS did extremely well during our sound test, with the on-track note being fairly pleasant.

As for downsides, the fit and finish was one of the lowest in the test. The pipes were actually rusted inside by the time they reached our hands, the pip tips coming out of the carbon caps were jagged and roughly cut. We also noticed that one of the mid-pipe mounts was tacked welded on in the corners and hadn't been finished down the length of the mount with a full weld bead. Lastly, the fit of the pipe wasn't the best as the mid-pipe and exhaust mounts were extremely hard to line up with the subframe and get all the hardware in straight. All-in-all, the power and sound impressed us for our first go with HGS, while the overall quality took it out of contention.

To shop for HGS Exhausts in the USA, head over to BudRacing-USA.com.

Want to see more Shootouts? Well we've got them, hit the links below for more.

Vital MX Shootout: The Best Neck Brace

2018 Vital MX 450 Shootout

2018 Vital MX 250 Shootout

About the Test Rider

Michael Lindsay // Age: 25 // Height: 5' 8" // Weight 155 lbs.
Riding Experience: Somewhere between really good and really bad...

Michael Lindsay - is a born-and-raised moto freak and gearhead from the heart of motocross in Southern California. First swinging a leg over a bike at the age of five, he immediately caught the racing bug, spending nearly every weekend behind a gate…and a lot of time on the couch while injured. While swinging back and forth between moto and the off-road scene, giving him a wide range of experience on the bike. Of course, all of this led to one thing: Lindsay loves working on his bikes almost as much as he loves talking about them. When he’s not in the Vital MX forum or writing his latest product review, you can find him out at the track taking dirt naps, snapping some pictures, or drooling over the latest parts for his bike. With an outspoken personality, gearhead background, and as Vital MX’s guru for product, Michael is here to share his unbiased opinion.

Photos, video, and words by Michael Lindsay