RoadsterSport RACE for MX5-ND
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RoadsterSport RACE


Just 12 pounds!

A Revolutionary Helmholtz Chamber Race Muffler for Max Fun!

PART NUMBER: 61-1733


Reg. Price: $481.85

Sale Price: $419.00



Free shipping offers apply only to destinations within US Lower 48.

Reg. Price: $481.85

Sale Price: $419.00



Free shipping offers apply only to destinations within US Lower 48.


Most FUN Miata race muffler right here, yet not for everyone!

Call it Dual Personality, Call it Jekyll and Hyde, this is the Rebel in our exhaust lineup and the sound level result depends on what you are doing with the gas pedal and the gear selection. Designed originally as our SCCA CS autocross muffler for those in competition on the weekends that want something that will pass SCCA sound limits for competition days and be fun on the way to and from work during the week. Slam the gas to the floor and run for redline and you get a wonderfully throaty throbbing exotic racing rumble with lots of burble that sounds BETTER than an MX5 Cup Car. BUT when you close throttle our unique tuned helmholtz chamber clips the midrange drone you would otherwise get with any setup this minimal, making it relatively mild on decel and when just cruising in top gear on the freeway. What we have here is the first Miata Race muffler sane folks can really live with every day without pissing off the wife or the neighbors (unless they WANT to).

The secret to getting all this fun without the pain of drone on decel is the exclusive Helmholtz chamber included in this design. In fact, this design is ALL Helmholtz and no traditional sound absorbing materials unless you get the optional race baffle.

Tarnish Alert! One downside of making this minimum weight is no fake double walled tip to keep the outside metal looking pretty, you must expect with this single walled choice that it will tarnish with heat because that's what happens to single walled stainless steel. If that will bother you, get any of our other choices that has a double walled tip and weighs more as a result (see our SuperStreet Single and TwinTip in particular since they are based on same straight pipe design).

How did we do it? We outfitted our 2016 with a computer and sound spectrum analyzer and microphones and drove it under varying conditions and loads with and without muffler. We then use that data and some special software to calculate the particulars of the Helmholtz chamber to precisely knock down the frequencies we do not want to hear in the car while allowing the good throaty burble fun sounds to pass through. In brief, FUN when you want it, and mild when just cruising. The Helmholtz chamber knocks down over 40db of sound in the 120-130 hertz range. That does NOT mean no bass sound, it does mean massive reduction of drone you otherwise get with a straight pipe design

All this in a 12 pound design, a big drop from the 20.5 pound factory muffler. Includes a straight through high flow design from the midpipe out the polished pipe tip for max power.

SHIPPING NOTE...ships factory direct to you. All POLISHED 304 stainless steel construction and LIFETIME warranty. Uses stock hangers and connects to either our midpipe or the stock midpipe.

NO BAFFLE INCLUDED but takes our optional Race Baffle that slides in and lowers sound level for the extra long drives or between racing weekends (baffle sold separate on this website).

IF you have more than 20,000 miles add a fresh donut gasket, our item 61-2144, factory part number RFK2-40-581) The factory designed the joint between muffler and midpipe as BOTH a flex joint and a sealing point and the impregnated graphite 'donut' gasket slowly grinds itself thinner and thinner. Those under 20k miles usually find the original still works great, those over about 20k miles usually best to start with fresh donut.

Proudly made in the USA, emissions legal in CA and every other State of the Union.

BRIAN'S APPLICATION NOTES: Mild when cruising on otherwise stock ND, delivering a classic sports car BARK and THROATY RUMBLE when you wind it out to redline. Fun burble when just playing with the throttle around town. Easily UNDER our local SCCA sound limits on otherwise stock Miata (our SCCA limit here is 93 db at 50 feet and even in the rain our testing found it easily under our strictly enforced sound limits). Also easily under the most strict 92db days at Mazda Raceway Laguna Seca when used on otherwise stock ND. Result is TONS of fun, will make many of you laugh out loud. You also get the best performance from the straightest and cleanest flow out the exhaust cutout you can get, and much lower weight.

NOT for the faint of heart!!! The most common question we will get on this one is: "will it be too loud" and we cannot answer that one for you because the "right" sound level is a matter of entirely subjective personal preference. We can say our experience with thousands of customers has taught us that Automatic transmission owners prefer our bigger SuperQ muffler choices. If you think it normal to drive a Miata around town always in the 1000 to 2500 rpm range, lugging the motor as if a Miata is a diesel truck, we suggest that this is not your muffler. If you are not going to use the motor for the fun to be found from 3000 rpms through redline every week, we ask you please get one of our bigger choices like the RoadsterSport SuperQ. IF you visit redline often, this might be your muffler! We tune the helmholtz chamber for the range that most folks cruise down the freeway in the car, knocking down over 40 db at peak drone in the 120 to 130 hertz range between 2700 and 3200 rpms. Without the helmholtz chamber the major drone peak is 2700 to 3200 rpms with a pure straight pipe. The goal was straight pipe performance reasonably tamed with minimum weight so it can be enjoyed in a daily driver that might go SCCA race on the weekends.

If our RoadsterSport SuperQ is 10 to 15% more sound than stock (depending on use of removable baffle), this RACE is a full 50 to 55% more sound than stock when on throttle, though perhaps just 20% over stock when cruising home in high gear down the freeway. Not designed for use on car with header or midpipe change, designed for max fun on otherwise stock exhaust system. Adding header adds a massive amount of sound, thus we suggest customers considering adding a header should look to our SuperQ choices. The issue with using adjustable length midpipe with this three hanger design is that customers rarely get the length correct and that can put too much stress on the connection between helmholtz chamber and straight pipe, so if you insist on adding midpipe with this design be careful to get length of midpipe accurate (hangers aligned nicely straight up and down for midpipe) and use thicker hanger from the rear to better support the bigger midpipe.

Slant cut to dress it up just a bit!

Ride Along with our RoadsterSport Race in a Launch Edition owned by local customer Mark Booth below, big thanks to Mark for the great video!

Note the RACE does not include any baffle but we offer an OPTIONAL

Packed Baffle that gives you the ability to quiet it down significantly. Adding our RoadsterSport Midpipe doesn't change the character of the sound but adds ANOTHER 20% more sound over and above what you get with the RoadsterSport Race. Below is a sample of that sound combo of our RoadsterSport Midpipe and this RoadsterSport Race muffler courtesy of our own Ryan Passey:


Installation of this Miata exhaust is SUPER EASY using the stock hardware already on the car...just two stock 14mm bolts to loosen! When you open the big box you will find separate foam wrap on the exhaust tip, leave that foam around the tip during your install to protect the polished tips and your car's soft plastic in the exhaust cutout. Use gloves. Note the 'bolts' from the factory are actually studs with springs and nuts and the factory usually jams the nuts on so hard that unbolting it will bring the stud out too. If that does not happen then use a 13mm long socket to unscrew the studs, or use jam nut technique where both nuts are put on one stud against each other and then wrench used on the inner of the two to back out the stud. Then lube up the stock exhaust hangers with dish soap and yank stock muffler back and forth to work the soap into the rubber hangers and then the muffler will slide off those rubber hangers easily. Then hang the new muffler on the wet and soapy rubber hangers and torque 'bolts' with the springs back in place to 30ft/lbs. Now you can remove foam tip wrap. Note the muffler to midpipe joint is a ball socket connection for the first time on a Miata, it is designed to move a lot on that very special stock high density ball socket gasket, so please do not add sealants that will gum up that dry ball socket joint. Our pipe size is bigger than OEM for best flow, that means the stock donut gasket sinks a bit deeper than with factory muffler. Our flange is designed as a dual purpose item that allows going to flat gasket if you later go 2.5 inch midpipe, at which point the midpipe has a flex joint to replace function of the donut. After install hold you hands about 2 inches from gasket connection with car running to check if you feel 'puff puff puff' indication of leak against your hands, if you do check your install or replace the factory gasket (our item 61-2144, factory part number RFK2-40-581 )

Local Fast Buddy Jeff Cawthorne laying down fast time in his new ND. Our RoadsterSport Race muffler adding some sound!

And leaving the line at SCCA autocross event:

Another Great Customer Video

Finally, TWO customers with this Race muffler, one following the other on the sort of fun canyon drive that Miata dreams are made of!

Dyno Results! From Grassroots MotorSports Magazine's testing, 8 hp from just a muffler on ND1...when the muffler is a straight pipe design like RoadsterSport Race and SuperStreet Single Tip and SuperStreet Twin Tip.

INSTALL Video Summary for RoadsterSport Race, and SuperStreet Mufflers..

INSTALL Video In Detail: Note there are DOZENS more install videos by customers on Youtube if you want even more views of the process.


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Customer Reviews

RoadsterSport RACE

Definitely worth the money, massive upgrade over stock.

Perfect match for the car! I am definitely not a do it yourself car guy, but even I managed to bolt this thing on in about 30 minutes, and that included some time to work out the bolts from the stock exhaust as mine were locked in.

As for the sound, its perfect, and I can't imagine anyone coming from any type of sports car/racing background finding this to be a loud exhaust. At low rpm lugging it can be a bit bassy and I will admit maybe a touch more than I would want just lugging around. But as soon as any sort of throttle is applied its absolutely perfect, in volume and character. Ads so much to the driving experience and the full throttle 7500rpm wail is a must experience!

Up here in the high elevations every single HP counts, and for sure there is just a touch more throttle response as well. For the money I just can't imagine a better upgrade.

I know people are always talking about the sound this product produces, but the 1st thing I noticed was a quicker throttle response, love that and the sound it produces also. Now, as for whatever increase in horsepower people have talked about, since it is actuality a straight pipe with a Helmholtz Chamber perpendicularly attached, the HP is increased slightly. Thanks Brian, for noticing a customer, not many companies do that these days.

It was a toss up between the RoadsterSport Race and the SS Race, went with the Race. I knew I didn''t want any baffles, why spend the extra money. Glad I did, OEM sounded like a sewing machine. Amazing sound on the get up and yet on steady throttle it's normal. Down shifts I no longer need to look at the tachometer because I can hear the motor through the exhaust. Great job Brian, thank you. Bought an exhaust pipe removal pliers, well worth the $35. Still utilized soapy water. Used a floor jack on the passenger side for a minor added clearance. From start to finish it only took me 35 minutes excluding clean up. Added a cold air intake during the summer, minor sound increase. Combination of both is amazing. Great job Good Win engineers, want added sound, power, go with the roadster street race. My other toy is a Harley loud pipes are in my blood!

Good build quality, light weight, practically no drone at low revs, and it was a straightforward install.
I can consider this as an expensive product (considering that this is just the axle back), but it will not disappoint. The chamber to cancel out the drone at low revs is a huge help for highway driving. The Miata comes alive at mid-high revs.
I would have loved it more if it was around the $350 price range ;)

I picked this exhaust up on a whim late one night wanting more noise for my brand new MX-5 and boy am I glad I picked this one. It's absolutely perfect in my opinion. It's very much a dual personality exhaust but without any fancy electronics or cut outs etc. It's very quiet when given gentle throttle inputs but when you lay into it, it really starts to shout, rumble and burble with a distinct trumpet effect. On start-up you receive a sharp bark that can be tamed by simply starting the car in reverse gear so you've got options if you want to show off or tip toe out the back door.

This can be the loud, boy racer, ricer exhaust of yours and my dreams or it can easily putter by a cop without drawing a second glance.

Get this exhaust if you want something that makes your Miata sound like a race car but also want to respect your neighbors and use a drive-thru without turning the car off. A race car exhaust for grown-ups. The perfect amount of noise.

Love this exhaust. Install couldn't be easier. Sounds great. Not too loud and minimal drone.

Quality product with amazing sound. Really breathes life into the whole driving experience. Smiles guaranteed, huge upgrade over the stock exhaust.

As Brian notes, this is not for the faint of heart. I had a chance to test drive beforehand, so I knew what I was getting into. It's not as loud as I thought. It is actually quite livable, and surprisingly so at highway speeds. At night/in residential areas/inside parking garages/on cold starts, though, it is going to feel loud. It's not as obnoxious as some of the other vehicles I hear in my neighborhood, but I do feel I have to be more careful in certain situations.

After some delays with having a shop install the exhaust, I said screw it and installed it myself. Install was straightforward, even for someone like me who is not handy at all. I borrowed a breaker bar, torque wrench, and wrench with 14mm socket. I did not have any way of lifting my car, but I am a skinnier guy and was fine working with the car on the ground.

For the inexperienced like me, I recommend ordering a couple spare studs ahead of time. If you Google around, you'll find it's not uncommon for the studs to be stuck to the stock muffler. Mine would not come off, even after the two-nut method and gratuitous soaking with WD-40. Fortunately I was able to source an OEM stud quickly (the part number is: B31R-40-584).

Secondly, I purchased a muffler hanger removal tool, and that thing was a life saver. The rubber was stuck on even after letting it soak with soapy water, and I figure the tool saved me an hour's worth of struggle.

In summary, this is a fine product with excellent sound that will surely bring a smile to your face. Perception of loudness is subjective, but in my opinion it is lively but livable even for daily driving, but probably not ideal in a quiet neighborhood. Install is straightforward with the right tools. A spare stud and a hanger removal tool (both inexpensive and easy to source) were a lifesaver for me.

Sounds and feels great. The folks at Good-Win did an amazing job with the product. They describe it perfectly; loud and burbly when you're heavy on the throttle, mild when you're cruising. This is my only car, so this dual nature is a perfect balance of fun and livable.

I installed this at just over 40k miles, so I took their advice and got a fresh donut gasket to seal the mid-pipe to muffler connection. I'm glad I did because the old one was super burnt and no longer had a proper seal. Only good advice from Good-Win.

I haven't gotten to go on a canyon run yet, but am looking forward to it!

Install was simple on our 3k mile Miata. Absolutely love the sound. Very happy with the product and would recommend to all ND owners

Installed's like my Miata has seriously come alive after swapping the stock muffler with this Goodwin "Race" bolt-on. WOW! What a difference! Cold start sounds great, but where she really shines is at 4000+ rpm. Very happy so far, and it's honestly a whole new (and better) experience getting on the gas and now hearing some real sound coming from this little four banger. Good times

RoadsterSport RACE

The item arrived just a couple of days after the order was submitted. The stock exhaust removal was easy but despite penetrating oil use, the nut was stuck on the bolt... no problem... as I read the instructions and read the trouble shooting discussion on miata forum. I was ready with couple of 9/16" ID washer which slides over the wide portion of the bolt/stud. this was to compensate for the larger diameter of the Race exhaust and fit of the doughnut. installation took less than half an hour(sprayed penetrating oil on the nut about an hour earlier) without any leak.

At idle it sounds just a tad louder than the stock. At lower rpms 0-4k there is a bit of low frequency boom but that is to be expected. Tolerable and noticeable. Above 4k the drone is gone and sound is great. I can actually hear my exhaust now.

At highway speed, the wind and tire noise is so loud that I cannot tell any difference in sound.

Great purchase! highly recommended

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