A Revolutionary Helmholtz Chamber Race Muffler for Max Fun!
Stainless Steel ADJUSTABLE Sound MX5 Miata Exhaust
PART NUMBER: 61-1733
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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. 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 you do NOT get the drone and cabin resonance of those pure race cars, instead it gets 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).
Continuing with the dual personality, with the top DOWN it makes lots of fun sound as you work the gears, yet with the top up and cruising just a mild purr on mild acceleration and very little drone when you close the throttle or engine brake or run light throttle up hill.
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.
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 an 11 pound design, which is about half the weight of 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 stainless steel construction and LIFETIME warranty. Uses stock hangers and connects to either our midpipe or the stock midpipe.
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).
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, lots of 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. Nonetheless, this choice is 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 SuperQ choices. And 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 and low rpms. 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 and drop weight to even 11.0 pounds!
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!
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:
BRIAN'S INSTALL NOTES:
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.
MIATA MX5-ND 2016-2020
* FREE SHIPPING
MIATA MX5-ND 2016-2020
* FREE SHIPPING
MIATA MX5-ND 2016-2020
* FREE SHIPPING
MIATA MX5-ND 2016-2020
* FREE SHIPPING
For my decades of purchasing aftermarket exhausts, my RoadsterSport RACE exhaust purchase has been my most satisfying aftermarket purchase. From the ease of install, quality of the materials and the perfect sound, I am very happy with my RoadsterSport RACE exhaust. At first I had been concerned that the exhaust would be too loud or droney; much of my aftermarket exhaust experience have been with various Mustang models and none of those experiences will translate to this exhaust. In fact, I would not mind if the exhaust were even more aggressive, so I am considering the mid pipe purchase now. When I first removed the exhaust from the box, I was very worried, its essentially as straight pipe with the special chamber, but I soon discovered, it works wonderfully!
I have driven the RoadsterSport RACE for several thousand miles now and the nice tone is always enjoyable top up or top down. My last worry was also the sound would have a punk kid Honda civic sound, not at all. I have also noticed an increase in top end power and I believe my gas milage has improved almost 1 MPG. Thank you, Good-win racing for an excellent quality and designed product!
My ND2 got its Roadstersport Race (RR) when it had about 300 miles on it. It's really pretty awesome. Soundwise it gets it just about perfect. I can drive out of the neighborhood and not piss off everyone while warming up the car. But at the same time it sounds like business. Stick yer foot in it and it barks. There's enough high frequency to get that good ripping sound, like a 4-cylinder bike that's not quite as loud and doesn't rev as high - a lot like a detuned Ford BDA if you remember what Ford-powered Atlantic cars sound like. The sound bounces off of buildings, underpasses and tunnels the way it should and downshifting sounds great, with just a hint of crackle. It's not so loud that you'll get tickets, but I suppose you'll eventually get noticed by the natives if you are late-braking and downshifting into the same corner in the same old Maryland settlement every day, then planting your foot in it because the sound bounces off the old buildings in a righteous way that ought to happen more often. It's not good for critical music listening, but I didn't buy the car for that. As far as the performance stuff goes, the dyno sheet Goodwin touts is one thing, but another less obvious advantage is that it takes a pretty cheap significant chunk of weight out of the car. While the weight is low, it's pretty far away from the car's center of mass, so it's worth it. Weight is the enemy, so get it out wherever possible.
Installation was really easy. Lubricate the rubber mounts on the old muffler with dish soap. Remove the mounting bolts / studs whatever ya wanna call em. Put a small block of 2X 4 next to the old muffler and pop the rubbers off the hangars with a big screwdriver. Stick the grin-inducing Roadsterport joybox on the mounts and screw the bolts / studs whatever ya wanna call em back in place. 30 minutes to fun!
It's perfect! You can play it like a musical instrument. Quiet when you're cruising and yet sounds like an exotic sports car when you rev it out. Really adds to the driving enjoyment. Easy install. Excellent fit, finish and packaging.
After the first 5000 miles with the stock exhaust, I decided to change. I don't do track or autocross, but we have lots of nice twisty roads in my area.
So far, the race is just what I want. I can baby it when I don't want to sound obnoxious, but for spirited driving on twisties it sounds so much better than stock!
Here is a video of my first real drive with the race: https://youtu.be/2X548gMvPD4
First upgrade to this beautiful car was this muffler. Sounds great and I expect it to get a little better as the car breaks in. Fit and finish was top notch. Fastest muffler I have ever installed. Mostly because car had only 250 miles on it and working off a lift.
So so happy I went with the Race exhaust over the quieter versions. I was going to go with superstreet but after my friend picked up a Race, I was sold. I wouldn't consider this exhaust loud or ricey at all. However, when you go WOT and open up, people know you're there. I drive mostly city and at low, casual driving and throttle speeds, it is still a lot of fun without being too loud. There is definitely some weight savings with this axel back as well. I was concerned with CA exhaust laws so I tested the dB with my phone for a rough estimate. The highest I ever got during testing was 82dB 12 inches away from the rear around 4-5k rpm. This is well below legal.Tips for install: i installed this on a 2019 with about 3k miles on the car. When you remove the stock exhaust, the donut flange was already molded to the stock exhaust. I was getting some noise/air leak from this point and some drone initally after install. However, after driving the car for a couple days this all went away. I believe what is going on here is that the heat from the exhaust has to mold the donut again around the flange. This heat combined with road vibrations probably seats everything nicely after a long drive. Thanks Brian for a wonderful product!
Can't keep my foot out of it! It sounds so good under throttle and on decel, yet very well mannered at even throttle. Well done GWR. Had a Corksport cat-back on a '11 Mazda3 and the GWR Race puts it to shame.
I am extremely happy with the muffler.
Fast delivery and easy installation.
Only issue is my foot got a little heavier listening to the sound. I have a 2019 model so winding it out has decreased my gas milage .02 per mile but my fun factor went up 100%.
I purchased this exhaust as a Christmas surprise for my girlfriend's new MX-5. Such a great car deserves a great sound, and while not whisper quiet, it wasn't very exciting. First off, I wanted this to be a surprise so I installed it in the floor of our garage at midnight after work (2nd shift). Armed only with a ratchet set and a big flathead screwdriver I was able to go from in-box to finished in something like 25 minutes, laying on a big piece of cardboard under the un-lifted car. Now for the sound. Its incredible the tone created by such a simple setup. The throaty grumbles off idle certainly don't sound very Miata-esque. Up through the rev range, it sounds more like a Euro or exotic than a Japanese 1.5L and though its quite raspy, there's no sign of that Honda Civic bumblebee buzz. However, what differs from every aftermarket exhaust I've ever dealt with is the complete absence of drone. With the top up you get full-throttle rumbles, but nothing that makes your ears pop. 6th gear at 55, 60, or even 80 mph is barely any different from stock. You can tell its there but you can easily forget it and enjoy the radio, and lets be honest the soft top NDs aren't quiet inside on the highway to begin with. I wish I could give it 10 out of 5 stars. I've bought many exhausts over the years and this one trumps them all! Perfect fit, excellent craftsmanship and superior customer service. A+++
What a great exhaust! Produces a nice sound that isn't obnoxious. Installation was easy, although I'd recommend using a lift if possible as it's much easier to work on being under the car for removing the bolts that attach to the midpipe.
This exhaust is amazing. I was so worried this was going to make my car sound like a ricer, but it did not. The sound is much deeper than stock. Wish my car was as fast as it sounded! Would 100% recommend if you want a car that sounds louder and sportier. Goodwin nailed it with this one.
It was as easy to install as everyone says; I did it by myself in about 20-30 minutes. I was a little apprehensive about putting it on because my wife hates loud mufflers and we both enjoy driving and chatting in the MX5. She borrowed the car (by herself) after I had installed it and returned with an ear-to-ear grin. She said "I didn't think you could make that car any more fun to drive, but you did".