Ultimate Guide to Mazda RX8 Exhaust Systems

Right out of the gate, Mazda’s RX8 sounds unlike any other car out there. But if you want to make it sound even better than it already does, consider upgrading your exhaust system.

Replacing your RX8’s stock exhaust with an aftermarket catback is easy. You can do this in your driveway with just a few tools and a set of jack stands.

All you need to do is unscrew two nuts, remove a few rubber hangers, and the stock exhaust comes right off. The rest is straightforward.

But the question remains — do aftermarket exhaust systems work on the RX8? The answer depends on what your purpose behind installing an aftermarket exhaust system is.

If you’re in it for the sound, pops, flames, and a mild bump in power (~5 hp), then yes, buying a catback is a good idea. If you’re expecting serious gains (~20 hp) from just the exhaust, then you may be disappointed.

Upgraded exhaust systems give you the best results only when you include other mods in the mix — like headers, an upgraded throttle body, midpipe, cold air intake, and the like.

In this guide, we’ve listed the best RX8 exhaust systems you can buy, along with some information you need to know before you start modifying your car.

Modified Mazda RX8 with stock exhaust system

Things To Know Before Upgrading Your RX8’s Exhaust

Mazda wanted the RX8 to be an approachable sports car for budding enthusiasts. And it is exactly that, except for one minor problem — it’s both expensive and difficult to modify properly.

Preventative maintenance is a big deal with rotary engines. Typical issues that you’ll run into include:

  • Blocked catalytic converter: telltale signs include poor throttle response and inability to reach high rpm.
  • Weak ignition system: higher fuel consumption, misfiring, uneven idle.
  • Corroding oil cooler lines: this can be spotted by removing your front wheel arch liner.
  • Bearing failure: this happens when you let the oil level run too low. Symptoms include low rattle, knocking, and rattling around 7000 rpm.

The list goes on. And these issues are typically seen on stock Mazda RX8s. When you start modifying it, you really gotta up your maintenance game, keep your ears perked up for any unusual noises, and monitor your oil level every single day. That’s just how it is when you live with a modified rotary-powered car.

That said, rotary engines can make a ton of power when modified correctly. We’ve seen some unbelievably well-built RX8s churning out upwards of 500 whp from the seemingly tiny 1.3 L Renesis rotary engine.

Bear in mind that these engines are sensitive to modifications and expensive to fix. Blow one apex seal and you’re done. We recommend finding a technician who speaks rotary.

Talk to RX8 owners at your local Cars and Coffee, read informative guides like this one, and explore car forums before installing any upgrades — doing these things will definitely point you in the right direction.

Single vs Dual Exhaust

Common wisdom suggests that dual exhausts are better suited for v-configuration engines and single exhausts are better for straight engines like the inline-4 and inline-6. But what exhaust layout best suits your Renesis engine?

Single exit exhaust on a Mazda RX8

The single exit vs dual exit exhaust debate is a hot one, but it does come down to personal preference.

Single exit exhausts better suit the character of the rotary engine — they tend to marginally outperform dual exit exhausts because they do a better job at streamlining the exhaust flow and have better scavenging characteristics.

If you decide to go for a single exit exhaust, remember that your OEM rear bar will have an empty gap in it. Some people don’t mind it, but others hate it, so give it some thought before choosing which system is right for you.

Mazda RX8 with Dual Exhausts

Dual exhausts, on the other hand, are quieter. So if you prefer less drone and want something that sounds as close to “stock” as possible, consider dual exhausts for your RX8.

The Best RX8 Exhausts You Can Buy

The aftermarket community adores the rotary platform. It’s no wonder why RX8 owners are spoilt for choice when it comes to aftermarket exhaust upgrades.

Without any further ado let’s dive into the list of some of the best RX8 exhaust systems you can buy right now.

Racing Beat REV8 Dual

Manufacturer: Racing Beat
Part Number: 16397
Piping Diameter: 76.2 mm
Tip Size: 101.6 mm
Layout: Dual Exit Catback
Construction: 304 Stainless Steel
Compatibility: Series 1 and Series 2

Strike up a conversation about the best RX8 exhausts and the name “Racing Beat” is bound to come up in conversation. Their REV8 is a massive hit among RX8 owners for multiple reasons.

Even though it weighs more than the stock exhaust, it noticeably improves the throttle response, especially when you pair it with a midpipe.

This is definitely among the quieter RX8 exhausts on this list. It sounds full and bass-heavy in the low end but does not drone. As you climb up the rev range, it gets louder and deeper but without any annoying rasp.

Under 3000 rpm you’ll hardly notice it’s there. Be sure to pick up the right model though — Racing Beat makes two separate REV8 Dual units for the Series 1 and Series 2 RX8s. Part number 16397 works for Series 1 (2004-2008) and 16394 works for Series 2 (2009-2011).

HKS Legamax

Manufacturer: HKS
Part Number: 32018-AZ002
Piping Diameter: 65 mm
Tip Size: 100 mm
Layout: Dual Exit Catback
Construction: 304 Stainless Steel
Compatibility: Series 1
Buy On: Amazon | Enjuku Racing

For those of you who like their exhausts quiet, the HKS Legamax is a solid contender. It’s not as loud as the Greddy SP2 (next on the list) but it is quieter than the Racing Beat REV8 exhaust.

You can combine the Legamax catback with the HKS intake to gain 6 hp and even more if you combine these with a test pipe or a high-flow cat and headers. But at that point, you’re going to have to modify your fuel and timing map considering how sensitive the rotary engine is.

The HKS Legamax comes with “Advantex Muffler Packing” which helps to boost durability and also helps with noise/drone cancellation.

Greddy Supreme SP

Manufacturer: Greddy
Part Number: 10148200
Piping Diameter: 63.5 mm
Tip Size: 102 mm
Layout: Dual Exit Catback
Construction: 304 Stainless Steel
Compatibility: Series 2
Buy On: Amazon | Enjuku Racing

The Greddy SP2 is priced reasonably low, looks great, and comes with a limited lifetime warranty. This hand-welded 304 stainless steel exhaust features dual, horizontally connected mufflers that are designed to enhance exhaust velocity and provide a smooth, deep exhaust note.

One minor gripe with this exhaust is the large Tips. If you dig the oversized exhaust tip look, then you’ll really love the SP2. Consider using exterior paint protectant because these Tips will melt some of the paint around your exhaust shrowd.

A’PEXi Hybrid Mega EVO

Manufacturer: A’PEXi
Part Number: 116AZ009
Piping Diameter: 70 mm to 75 mm
Tip Size: 105 mm
Layout: Dual Exit Catback
Construction: Stainless Steel
Compatibility: Series 1 and Series 2
Buy On: Enjuku Racing

The A’PEXi Hybrid Megaphone EVO exhaust is quite underrated in the RX8 community. Possibly because there are many other options in this price range. However, give this exhaust a good inspection and you’ll see that the quality justifies the price.

Everything from the internal silencers, resonators, hangers, and brackets is constructed using high-tensile S304 stainless steel. Overall, this unit looks great, but it sounds even better than it looks.

Expect to hear a bass-heavy burble at idle — the exhaust note gets angrier and louder as you climb up the revs.

Borla S-Type

Manufacturer: Borla
Part Number: 140078
Piping Diameter: 76.2 mm to 57.1 mm
Tip Size: 101.6 mm
Layout: Dual Exit Catback
Construction: 304 Stainless Steel
Compatibility: Series 1
Buy On: Amazon

If you had to choose just one exhaust system from this list, then make sure it’s this one. The Borla S-type is extremely popular in the RX8 community for all the right reasons — it’s priced modestly, looks great, is easy to install, and provides noticeable gains when paired with a test pipe.

The S-type sounds timid and unintimidating below 3000 rpm, but on wide-open-throttle, it screams — not in a harsh way though, it sounds deep and full-bodied. Very similar to the Racing Beat exhaust, only lighter.

HKS Hi-Power

Manufacturer: HKS
Part Number: 31006-BZ001
Piping Diameter: 75 mm
Tip Size: 97 mm
Layout: Single Exit Catback
Construction: Stainless Steel Piping | Titanium Tip
Compatibility: Series 1
Buy On: Enjuku Racing

Whether loud pipes save lives or not is up for debate. But if you like your pipes unmistakably loud, then you’re in for a treat. The HKS Hi-Power is the loudest, lightest, and cheapest exhaust on this list.

Tipping the scale at 30 lbs, this exhaust is exceptionally light — much lighter than the stock exhaust. Part of the reason for this is that it’s a single-exit exhaust. Combine this with a straight pipe and your RX8 will be spitting flames in no time.

Agency Power T-14

Manufacturer: Agency Power
Part Number: AP-RX8-170
Piping Diameter: 76 mm
Tip Size: 102 mm
Layout: Dual Exit Headerback
Construction: Stainless Steel Piping | Titanium Tips
Compatibility: Series 1 and Series 2
Buy On: Amazon

The Agency Power T-14 is yet another favorite among RX8 owners. This is a header-back exhaust system, which means it comes with a resonated midpipe. Talk about a bargain!

That said, if you plan on installing a different midpipe than what this unit comes with — perhaps the popular Black Halo Racing (BHR) midpipe — you could either steer clear from this particular exhaust or be prepared to sell the midpipe it comes with.

Agency Power exhaust melted Mazda RX8 rear bumper exhaust shroud

The only downside with this exhaust is the thin titanium tips; they tend to fade over time. When you install this exhaust, make sure there’s enough clearance between the tip and the exhaust shrouds or they will melt. Installing a Mazdaspeed rear bumper is an option if you want enough clearance.

TurboXS RX8 Catback

Manufacturer: TurboXS
Part Number: ‎RX8-CBE
Piping Diameter: 76.2 mm
Tip Size: 101 mm
Layout: Dual Exit Catback
Construction: 304 Stainless Steel
Compatibility: Series 1
Buy On: Amazon

The first thing we noticed about the TurboXS catback is the outstanding build quality. Unlike some other RX8 exhausts, this one will retain its sheen and structural integrity even after years of use (and abuse).

If you’re thinking of going catless, know that straight-piped TurboXS exhausts get extremely loud and raspy. A dual resonated midpipe is your best bet if you want to get rid of your restrictive stock cat and still run this exhaust without it getting too loud.

If you’ve heard rumors about this exhaust not fitting well with the stock cat-con, don’t worry. The fine folks over at TurboXS include a 2.5” to 3” gasket in the box so that it can easily fit your stock catalytic converter.

It’s worth mentioning that Series 2 RX8 owners will need to purchase and install longer exhaust hangers for the TurboXS catback to fit properly.

Odula RS Spec

Manufacturer: Odula
Part Number: SE079
Piping Diameter: 70 mm to 80 mm
Tip Size: 100 mm
Layout: Dual Exit Muffler
Construction: Stainless Steel
Compatibility: Series 1 and Series 2

If you’re someone who truly appreciates 100% authentic Japanese performance parts, then the Odula RS Spec will interest you. It’s quite unpopular and unlike any other exhaust in this list — except the Super Dolphin Tail by RE Amemiya. More on that later.

The Odula RS Spec exhaust sounds exotic accentuates the classic rotary sound. Considering how old this exhaust is, your chances of finding one brand new are slim. So if you really want one of these, you might have to scour the used parts market.

B&B Catback

Manufacturer: B&B Performance Exhaust
Part Number: FPIM-0900
Piping Diameter: 63.5 mm
Tip Size: 101.4 mm
Layout: Dual Exit Catback
Construction: Stainless Steel
Compatibility: Series 1

B&B stands for Billy Boat — a professional racecar driver and master fabricator. B&B Performance Exhaust started out building specialized Porsche 911 performance exhaust systems, oil coolers, and intercoolers.

Their catback for the RX8 offers a solid bang for your buck considering how well built it is and how great it sounds. It fits perfectly, with no issues during installation whatsoever, and no burning shrouds as a result.

Don’t expect to gain the manufacturer advertised 18 horsepower. However, 10 to 14 horsepower (at the crank) is achievable with the B&B exhaust so long as you’ve gotten rid of the stock catalytic converter.

This is one of the deepest sounding RX8 exhausts you will find. Audio clips don’t do justice; you need to hear one of these in person.

Amuse R1 Titan Extra

Manufacturer: Powerhouse Amuse
Part Number: AMS41414330002
Piping Diameter: 70 mm to 60 mm
Tip Size: 100 mm
Layout: Dual Exit Catback
Construction: Titanium
Compatibility: Series 1 and Series 2

Amuse is a household name in the tuner scene. They’re known to make some of the most high-quality titanium components and the R1 Titan Extra exhaust is no exception.

Because it’s a full-titanium system, it is significantly lighter than the stock RX8 exhaust and offers serious weight reduction. It looks fantastic; even though many of us dislike burnt tips.

And the best part is that it sounds glorious — our personal favorite in this list when it comes to sound. Unfortunately, Amuse recently discontinued this system, but we expect a new line of products soon.

You can still snag one of these if you manage to find unsold stock. Or you’ll have to scour the used parts market.

Invidia Q300

Manufacturer: Invidia
Part Number: ‎HS04ZR8G3S
Piping Diameter: 70 mm
Tip Size: 110 mm
Layout: Dual Exit Catback
Construction: Stainless Steel
Compatibility: Series 1

The Q300 catback exhaust by Invidia is well designed, and affordability priced. The flat-bottomed muffler gives you plenty of clearance so you won’t have to worry about damaging it when going over bumps.

The piping is much straighter and has fewer bends compared to other RX8 exhausts on the market. If you drive a series 1 RX8, the fitment won’t be a problem.

Do be aware that Series 2 RX8 owners will require longer exhaust hangers for this exhaust to fit correctly.

RE Amemiya Super Dolphin Tail + Chamber

Manufacturer: RE Amemiya
Part Number: M0-088035-S16
Piping Diameter: 63.5 mm
Tip Size: 90 mm
Layout: Dual Exit Headerback
Construction: Stainless Steel
Compatibility: Series 2

As quirky as it sounds, the RE Amemiya Super Dolphin Tail is arguably the most unique sounding and hotly debated exhaust system on the market.

There’s no denying that it looks and sounds exotic, but the number of twists and bends right before the muffler is something that puts many enthusiasts off.

On the flip side, this exhaust comes from the legendary rotary tuning house RE Amemiya. Isami Amemiya, a.k.a Ame-San is a well-known rotary-tuning specialist and many enthusiasts swear by the products he designs. Also, he’s rumored to be a former midnight club member.

Possibly, the aggressive bends are there for a reason, perhaps for higher exhaust velocity and better scavenging characteristics at a very specific rpm range, but no one really knows for sure.

Fujitsubo Legalis R

Manufacturer: Fujitsubo
Part Number: 790-45051
Piping Diameter: 76.3 mm to 60.5 mm
Tip Size: 90 mm
Layout: Dual Exit Catback
Construction: Stainless Steel
Compatibility: Series 1 and Series 2

The Legalis R by Fujitsubo is very close to the Borla S-Type exhaust in terms of looks and sound. The tone is deep and quiet, but it gets loud at WOT.

You get 130 mm of road clearance thanks to the oval muffler. This is not a lot, but it’s more than what you’ll get on most other RX8 exhausts.

Overall, this exhaust is a great dual exit cat back system to consider for daily driving and street use.

Tanabe Medalion Touring

Manufacturer: Tanabe
Part Number: ‎T70097
Piping Diameter: 70 mm to 60 mm
Tip Size: 90 mm
Layout: Dual Exit Catback
Construction: 304 Stainless Steel
Compatibility: Series 1
Buy On: Amazon

Tanabe’s Medalion Touring range is often seen on the Nissan 350z or Infiniti G35. We haven’t seen many RX8s equipped with this exhaust though.

This catback is advertised as “touring” exhaust and rightfully so. It has a clean tone that sounds a lot deeper than the stock exhaust.

The drone is minimal, so cruising at highway speeds for prolonged periods of time should be hassle-free.

Honorable Mentions

Now we can’t list every single exhaust system out there, but there are a few that could’ve made this list but didn’t for several reasons:

  • Remus Duplix 1570TD
  • Hymee MK3
  • Cobra Sport MZ08
  • JIC Magic DE-2
  • Trust Power Extreme Ti
  • Exoticspeed R1-T and S1-T
  • Pettit Racing Modular (Milltek)

Final Thoughts

The RX8 is one of those cars that are overly sensitive to any modifications. It’s easy to make it sound great, and it’s equally easy to make it sound terrible.

Either way, it’s important to acknowledge that the effectiveness of any catback or axleback exhaust is very subjective.

Without a midpipe or aftermarket headers, there isn’t a lot to be gained. Except in the looks and sound department — that’s the primary reason why most enthusiasts buy catback exhausts in the first place.

Tastefully modified Mazda RX8

Remember that video and audio clips don’t do justice to exhaust sounds unless they’re recorded with a high-quality microphone and if you’re studio-grade headphones or in-ear monitors for playback.

Most videos on YouTube aren’t high quality, so try to listen to your preferred exhaust in person before making a decision.

Our Top 3 Favorites

Honestly, you could literally buy any exhaust on this list and not regret your purchase. Except maybe the Amuse R1 Titan Extra — by all means, go for it if budget is not a concern. But if it is, then you can put that money to better use.

For instance, instead of shelling out for the R1 Titan, you could buy the HKS Hi-Power exhaust and still have around $3500 left for other mods. But the Hi-Power exhaust is quite loud — some might dig that, some might not. To each their own.

There are simply too many variables to consider. With that in mind, here are our top 3 favorite RX8 exhausts:

Best Bang for Buck: HKS Hi-Power

We just can’t get over the fact that this exhaust is as cheap as it is. You definitely get more than what you pay for. Because it’s a single exit exhaust, it suits the character of the rotary engine and it has an upper hand in terms of performance when compared to other exhausts on this list.

The Nicest Sounding Exhaust: RE Amemiya Super Dolphin Tail

We’re going to go out on a limb here and say that the RE Amemiya Super Dolphin is the best sounding RX8 exhaust there is. Some of you probably think that it sounds ricey but, know that preferences like these are highly subjective. This contrast is what makes the car community so interesting.

Best Overall: Borla S-Type

Great price, great sound, and amazing build quality. What more could you want from an aftermarket exhaust. If you had to choose just one exhaust from this list, you’ll be really happy with the Borla S-Type.

What are your thoughts on this list? Are there any exhausts that you’d like to see on here? Let us know by leaving a comment below!

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