Many car manufacturers will choose the least expensive alternative when it comes to items such as exhaust systems. The best high performance exhaust system can free some of the power in your engine. These systems allow for a quicker, more efficient path for exhaust gases to escape. This means your engine “breathes” better, so spent fuel and air exit the combustion chambers faster. That means more fuel and air can be burned to create more power. Another good reason to add an aftermarket exhaust system is the change in exhaust note. Many of the better systems are only slightly louder than your stock exhaust at idle, but they deepen to a low “growl” during acceleration.
The Mazdaspeed 6 exhaust system is built in several sections. Here a diagram to help you understand and decide what part you want to change.
Downpipe
The downpipe on your Mazdaspeed 6 is the first part of your exhaust coming off of the turbo. The OEM downpipe on your vehicle contains one catalytic converter. Replacing your downpipe is a common upgrade that results in some very impressive power gains over your restrictive OEM unit while giving your car a louder, more aggressive exhaust note. When buying you will have the choice between short or long downpipe, they are referred to as either being cat-less or as having a high flow cat. A cat-less downpipe replaces your OEM piece with a new 3″ downpipe possessing NO catalytic converters. One possessing a High Flow Cat, also replaces your stock restrictive cat for a more efficient, higher flowing unit. Generally, cat-less downpipes provide a few more peak ponies and a more aggressive exhaust notes than pieces with a high flow cat, BUT at the risk of the car receiving a CEL.
*Note: It has been seen that after upgrading to a 3″ downpipe that some vehicles will end up with smoking turbos. This is because of the reduced backpressure on the turbo seals, which allows some oil to pass by. There are several easy fixes to resolve this issue, the first and simplest fix is to raise the idle on your vehicle through your tuning software (AP). Another simple fix is to swap out the stock oil feed bolt with a smaller diameter feed hole.
ATP | Stainless High Flow 3″ | Part Number: ATP-MS6-001
Downpipe, 3″ Stainless, catless, high flow, Vband disconnect at turbo for modular use and future expansion. Comes with v-band module for stock turbo. Downpipe is fully compatible with ATP/Garrett ball bearing turbo upgrades. Direct bolt up to stock exhaust 2 bolt flange on the rear. Unit also has extra 02 bung for wideband tuning and plug included. All CNC machined flanges, 304 stainless tubing, and TIG welded construction.
This downpipe offers big performance gains on cars still running the stock turbo or upgraded turbo. Even on the stock turbo, this free flowing downpipe will make as much as 50 ft/lb of torque on the bottom end and a lot of HP depending on the amount of boost you run.
Corksport | Stainless | Part Number: No Cat Ate-6-113-10/ Part Number: With Cat Ate-6-114-10
Get maximum turbo performance and dramatically increase torque with the Mazdaspeed 6 Power Series Downpipe. The CorkSport downpipe has been expertly designed to replace the restrictive element in the Mazdaspeed 6 stock downpipe. Mandrel bent piping is used to create smooth exhaust flow for dramatic increases in power. During initial testing, the CorkSport Mazdaspeed 6 Downpipe showed power gains of 26 horsepower and 32 ft. lbs. of torque at the wheels.
For lasting corrosion resistance and reduced heat transfer to the engine bay, the CorkSport MS6 downpipe uses polished 3” 304 stainless steel and features TIG welds that offer superior arc and weld puddle control for a cleaner appearance and precise weld bead control.
CP-E QKspl™ | Stainless | Part Number: No Cat MZDP00003T / Part Number: With Cat MZDP00004T
The downpipe may be ordered with or without catalytic converters, for use on-road or off-road, respectively. The off-road version includes the cp-e™ tuneable O2 Sensor kit to eliminate the unwanted check engine light. The catalytic converter equipped downpipe features a metallic monolithic honeycomb catalyst designed for maximum flow and surface area. With the downpipe installed, one can expect more than a 20 horsepower gain at the wheels, and a marked increase in engine responsiveness.
To keep the quality high, cp-e™ has used TIG welds to secure each piece of the downpipe. TIG welds are usually avoided in this industry because they require more time and skill than a MIG weld, despite the fact that TIG welds are better suited for thin metals, are better looking, and create a more durable bond.
Full Race | Stainless | Part Number: FRDPMS6
The Mazdaspeed 6 Prostock 3″ downpipe features a two piece design V-Band flange/clamp. It is a direct bolt-on replacement of the OEM downpipe. It is also 100% hand crafted and TIG welded in the USA for strength and durability. This downpipe offers big performance gains, great sound as well as no CEL light.
J2 Engineering | Stainless | Part Number: J2-DP-004
This downpipe is made of high quality T-304 Stainless Steel with Computerized Mandrel-Bends. It helps with maximizing exhaust airflow. The CNC machine Flange is TIG welded for strength and durability. By its design, this downpipe increase engine output and efficiency as well as make it gain 10-15 hps. It is also a direct bolt-on to your car, no modifications are needed to replace your OEM downpipe.
Kozmic | Stainless High Flow 3″ | Part Number: K27-MS6-DP-CPE-PTE
When upgrading to a cp-e manifold on your Mazdaspeed 6, you have the option of getting it with a Precision vband flange. After that, they do not make a custom fitted downpipe for the application. Kozmic decided to come in and complete the “kit” and make a really solid downpipe option. The Kozmic downpipe will ONLY fit when using a vband style in/out housing (3 5/8″ discharge) with a cp-e manifold. It’s made of 304 stainless steel and is TIG welded in Houston, TX at Kozmic headquarters. A flex joint is built-in to remove some of the stress on the pipe as it moves with the car and engine. Also included is a 3rd o2 bung for anyone needing to run a separate wideband AFR gauge.
M2 Performance (Manzo USA) | Stainless | Part Number: TP-176
This Mazdaspeed 6 downpipe is made of 3″ stainless steel for optimal air flow and increase in power. It is a direct bolt-on replacement of the OEM downpipe. Unit also has extra 02 bung for wideband tuning and it is also a long cat-less downpipe.
OBX Racing Sports | Stainless | Part Number: ???
This Mazdaspeed 6 downpipe is made of 3″ T-304 stainless steel mandrel bend for ultra fast flow and increase in power. It is a direct bolt-on replacement of the OEM downpipe. Unit also has extra 02 bung for wideband tuning and it is also a long cat-less downpipe. The CNC machine Flange is TIG welded for strength and durability.
Speed Daddy | Stainless | Part Number: DP-MS6-T
This downpipe is made of high quality T-304 Stainless Steel with Computerized Mandrel-Bends. It helps with maximizing exhaust airflow. The CNC machine Flange is TIG welded for strength and durability. By its design, this downpipe increase engine output and efficiency as well as make it gain 10-15 hps. It is also a direct bolt-on to your car, no modifications are needed to replace your OEM downpipe.
Test Pipe
A test pipe is a straight pipe that replaces the catalytic converter that can free up noticeable amounts of power. It can also be called Track Pipe or Racepipe depends of the company. You don’t need to buy this part if you buy a long downpipe.
Corksport Power Series | Stainless | Part Number: Ate-6-112-10
Get added horsepower from your Mazdaspeed 6 with the CorkSport Power Series Mazdaspeed 6 Racepipe. By replacing the second catalyst on your Mazdaspeed 6 with this direct bolt-on replacement, the severe air flow restriction is removed providing significant improvements in performance and power.
Constructed from TIG welded T304 stainless steel, the CorkSport Mazdaspeed 6 Power Series Racepipe has been expertly designed to fit with stock or aftermarket exhaust systems and downpipes.
OBX Racing Sports | Stainless | Part Number: ???
This 3″ test pipe is made of dual TIG weld high quality SUS-T304 stainless steel for best durability. It is a direct bolt-on without any modification. It is high performance track proven quality as well as the CNC machined 3/8 inch thick flange. Unit also has extra 02 bung for wideband tuning and it is also a long cat-less downpipe. The CNC machine Flange is TIG welded for strength and durability.
SURE M6™ | Stainless | Part Number: SURE0403
The M6 replaces the second factory catalytic converter on your Mazdaspeed 6 exhaust system. It allows your exhaust to flow more freely without any obstructions. The M6 is constructed using 3.00″ 304 stainless steel tubing and 3/8″ 304 stainless steel CNC machined flanges. Tig welded for ultimate strength. 100% stainless steel and 100% made in America, built to last. The 3” design of the M6, maximizes the flow which will result in top performance of your mid-pipe.
Ultimate Racing | Stainless | Part Number: 800165
This test pipe replaces the OEM secondary catalytic converter without CEL and without the need of a tune. Made from full 304 stainless steel construction it helps maximize exhaust flow. It is TIG welded to perfection and 100% Bolt-on OEM or most aftermarket catback exhaust. There is different variation for this test pipe. You can choose from: Straight, Resonated (Aids in the removal of in-cabin resonance), Ceramic Core Cat (catalytic converter support up to 450 hp) or Metal Substrate Core (catalytic converter support up to 750 hp)
Catback
A Catback system is an engineered exhaust system that’s designed to improve horsepower and deliver exciting high-performance sound. Called a Catback system because it is installed behind (or after) the catalytic converter, this system replaces a stock or factory muffler and exhaust pipe arrangement. Since the system comes after the catalytic converter, there is no disruption of exhaust gas emissions and therefore does not change factory emission output.
Corksport Power Series| Stainless Dual 3″ | Part Number: Ate-6-106-10
Get a nice deep tone and solid power gains through your entire RPM band with the CorkSport Mazdaspeed 6 Exhaust This dual muffler design uses ovaled 80mm stainless steel tips and factory hanger locations for a perfect OEM fitment.
Constructed from quality materials and using only the best construction methods, the CorkSport exhaust is designed with mandrel bent 80mm polished T304 Stainless Steel piping for a smooth exhaust flow and increased power. The CorkSport Mazdaspeed 6 Exhaust also features TIG welds for a strong, good looking connection.
CP-E Austenite™ | Stainless Dual 3″ | Part Number: MZAE00007T
The exhaust system is quiet, yet still increased the breathing potential of the turbocharged MZR. To that end, they pulled out all of the stops and integrated two of their immensely popular 12” oval mufflers into the 3” stainless steel system. The resulting sound is incredibly warm, it has a gentle burble to it at idle, and is totally devoid of any drone at cruising speeds. Of course, when you push on the go-pedal, it has a decidedly deeper tone despite that the overall sound volume hasn’t increased substantially.
They worked very hard to reach out as much power from this kit as possible by removing every unnecessary restriction in the factory exhaust. They used only straight through mufflers, unlike the stock chambered mufflers, so the resulting power penalty is negligible. Anytime you make exhaust gas change direction, like you do in a bend, you create unwanted backpressure. Instead of a “T” like the factory system has, their cat back creates a very gentle, proper “Y” transition, which will substantially increase exhaust flow over stock.
CP-E Austenite™ | Stainless Single 3″ | Part Number: No Resonator MZAE00003T / Part Number: With Resonator MZAE00004T
Optimal flow and minimal back pressure is the key to any turbo powered car. Knowing this Custom Performance Engineering (cp-e™) set out to engineer a cat-back system that features smooth mandrel bends and a muffler designed to minimize backpressure and promote faster spool up. The dyno-proven results of this effort speak for themselves, with a broad increase of horsepower and torque across the entire operating range of the engine.
The cat back system is manufactured using polished 304 stainless steel. All tubing is made in the USA by American Stainless Tubing, Inc.(ASTi) The tubing is all supplied in a super buff finish exclusive to ASTi’s manufacturing technology.
ETS | Stainless Dual 3″ | Part Number: ETS-MS6-Exh
ETS exhaust components are made of high quality stainless steel and tig welded by hand in their Vancouver, WA facility, right here in the USA. Known worldwide for their turbocharged application performance components, any ETS exhaust can be trusted to make the most possible power and is built to last. The ETS Stainless Steel Cat-Back Dual Exit Exhaust System for the MAZDASPEED 6 retains stock exhaust tips for maintaining stock appearance. This exhaust has low noise and deep tone that appeals to the car’s appearance. It is a direct bolt on and comes with all the necessary hardware for easy installation onto your MS6!
Magnaflow | Stainless Dual 3″ | Part Number: 16609
The Mazda Mazdaspeed 6 system was engineered to deliver the maximum performance without intruding upon the comfort and drivability of the car. In the development of this system, the factory “tip in fascia” look is replaced by a traditional large bore tip completing the rear of the vehicle with a true exhaust outlet. Made in the USA and engineered to last, for those seeking increased performance and better economy, MagnaFlow Street Series Performance Exhaust systems deliver the smooth deep sound you want and the wide-open performance power you need. Their exhaust systems feature straight-through flow designs for the ultimate in unrestricted horsepower and torque for big power while maintaining exhaust efficiency.
The Build of the Mazdaspeed6 