RoadsterSport SuperStreet for MX5-ND
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RoadsterSport SuperStreet


Stainless Steel PREMIUM ADJUSTABLE MX5 Miata Exhaust

Helmholtz Chamber Design Means Max Fun.

Just 14 pounds!

Gains 8hp in independent magazine tests!

PART NUMBER: 61-1787


Reg. Price: $688.85

Sale Price: $599.00



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

Reg. Price: $688.85

Sale Price: $599.00



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


WHY: Because YOU want to have fun!
HOW: Helmholtz Technology in a Miata Muffler for the First Time!
WHAT: A 2016+ Miata Muffler that you can control, aggressive throaty burble fun when you want with wide open throttle, and super mild when you want to just cruise.

This is a modified version of our all helmholtz Race muffler that adds an ultra efficient high density resonator before the tip to lower the volume while keeping the fun burble and playful character of our Race muffler. We also dress it up with a unique ultra light version of our 3.5 inch RoadsterSport rolled tip pictured below to finish the look for our street customers wanting something more luxuriously finished than the aggressively lightweight Race muffler:

Result is a 14 pound wonder of a street muffler, you get the great look of the RoadsterSport 3.5 rolled tip, the clean flow of 2.5 inches of pipe from start to finish with smooth mandrel bends on the shortest possible path from the midpipe to the exhaust cutout to max your horsepower gains...and minimal weight with these features. How much POWER? Grassroots MotorSports Magazine backed up our dyno results in the December 2016 issue, they tested and found peak gains of 8hp with no other mods, excerpt of that article below:

CLICK HERE to see the full article covering our SuperStreet muffler.

This muffler gives your right foot lots of control over the volume. The effect of the Helmholtz is very frequency specific such that under decel it can get mild and quiet, yet when you push hard toward redline it sounds exotic and racy. With the top down lots of fun throaty burble, but dramatically more tame when the top is up. In brief, FUN when you want it, and mild when just cruising.

How did we do it? We outfitted our 2016 with a computer and sound 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. All this in a muffler that is just 14 pounds, a nice savings over the 21 pound factory muffler.

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

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

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

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.

The SOUND level is Adjustable by YOU, INCLUDES removable cone baffle insert in the tip that helps YOU select final sound level, baffle in for reduced sound level, and baffle out for more sound...and just one bolt under the tip to make the easy change. Sold separate is an optional packed baffle that cuts the sound a little more if you want...but most won't!

Proudly made in the USA...with a LIFETIME WARRANY!

BRIAN'S APPLICATION NOTES: Famous Miata Racer Andy Hollis recently did his own dyno tests of this muffler and found it flowed as well as no muffler at all, with solid HP gains over the stock muffler, and he added: "BTW LOVE the sound!" Andy's dyno sheet reprinted on page 24 of our forum ND development thread and bottom of this page. Our Race and SuperStreet Twin Tip share the same straight pipe design with result they will make the same horsepower gains, but this is the customer top choice on sound when used without baffles. The little resonator just slightly civilizes the rowdy RoadsterSport Race, it's still very aggressive, with just a bit less high frequency notes in the balance than the pure Race.

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. 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.

Not designed for use on car with aftermarket header or aftermarket midpipe, 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 for best control of results with header change. The issue with using adjustable length midpipe with this ultra light three hanger design is that customers rarely get the adjustable length set 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.


Installation of this Miata exhaust is SUPER EASY...just two 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 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. Option to remove the baffle too, to do so loosen bolt that holds it from under the exhaust tip and use it as handle to shake the baffle loose and then unscrew bolt the rest of the way and pull the baffle (pulling baffle raises the sound slightly). IF not removing baffle, check torque, 15 ft/lbs on the retaining nut will be enough thanks to lock washer included. 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, so please do not add sealants that will gum up that dry ball socket joint. Our pipe size is bigger than OEM for best performance/flow, that means the stock donut gasket sinks a bit deeper than with factory muffler 'mouth'. Our flange is designed as a dual purpose item that allows going to flat gasket if you later go with our 2.5 inch midpipe, at which point the midpipe has a flex joint to replace function of the donut and you get a clean 2.5 inches of flow all the way, which is not possible if we stay same small pipe of stock muffler. 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 )



Super Street leaving the line at SCCA Autocross event.

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.

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.

Picture below of Konig Dekagram 16x8 4X100 ET35 Bronze with 205/50R16 tires, lowered on our MeisterR Zeta CRD coilovers, and also showing our RoadsterSport SuperStreet Muffler. Picture Courtesy Customer Brett Riese.

Picture below of Konig Ampliform 17x8 4X100 ET45 Dark Metallic Graphite and Our Progress Springs and SuperStreet Muffler Courtesy Ted7 - Automotive & Car Event Photography.

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

INSTALL Video In Detail:

One more installation video, this one for Single Tip SuperStreet but procedure is the same for Race and SuperStreet Twin Tip.


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Customer Reviews

RoadsterSport SuperStreet

After surfing the web, decided to go with the Goodwin RoadsterSport Super Street along with the Packed Baffle Insert for my new 2024 ND3 6-sp soft top. Installed in less than one hour and couldn't be happier with the sound. The "bark" is totally under the control of your right foot. No drone at all on the freeway.

Installed within an hour of receiving the package. Super easy install as noted on the website. I can 100% confirm this exhaust is completely compatible with the Curt hitch. Whereas the stock muffler rested on the hitch bar and the Borla didn't even allow room for the hitch to be fitted, the Super Street allows tons of room. Absolutely zero issues with clearance. In fact, if the hangers weren't in the way, I suspect you might even have enough room to do the hitch install without dismounting this muffler. Though it's so easy to detach from the hangers that it only makes sense to do so. I now wish I'd found the Hard Dog before purchasing the Curt. Would love the hide-away feature, perhaps some time in the future!

Also, for what it's worth, I much prefer the tone from the Super Street vs the Borla. My RF is my daily and I commute 20 miles one way across Houston traffic. So it is totally livable in traffic, whereas the Borla became annoying at times. And it sounds great when on a backroad in an environment meant for more exuberant driving. It fits the nature of the car very well.

Very pleased with this exhaust!

I am one of the least mechanically inclined people on the face of the Earth. However, I was able to install this without any issue. I lost a little time when I removed the old muffler, because one of the studs was stuck. However, after fighting with it for about 30 minutes I broke it free. This muffler sounds great! Not too loud at cruising speed, but roars when you want it to. Love this thing.

As reviewed elsewhere, super easy installation. The exhaust note gives the ND2 engine its due. Proper sports car sound. What a pleasure.

My one surprise (pleasant) was that I actually drove better. Rev matching downshifts when heel-toeing was improved as I could hear the engine much more clearly. These cars are so much fun!

What can I say? This axel back sounds fantastic. So much better than any internet sound clip. YouTube does not do this product any justice. It is nice and throaty down low and really starts to scream at higher RPMs. In my opinion it is the proper sound for this car. As for instillation? I am a novice at this stuff and it was a breeze, with one caveat, the exhaust hangers. Do yourself a favor and purchase an exhaust hanger tool. They are very inexpensive and are what makes doing this job a piece of cake. Also regardless of mileage on the car, order a new exhaust gasket because in my experience you are going to need it. And lastly, because I like to do everything contrary to the populous, I did not have a problem with the studs sticking in the factory muffler. For the life of me I could not get the nuts off of the studs. Those suckers are on for life. If you are contemplating this exhaust cogitate no more. This is the answer to a very uninspiring oem muffler.

My son and I installed in less than an hour. The hardest part was getting the rubber hangers loose. Also, one of the studs would not come off of the old muffler, so I bought another. I bought the donut from GW, but did not need it.

We removed the baffle; it sounds much better without it.

Brian's notes were very helpful.


Thank you!!!

I call it Miazda music:) Installed without the baffle and didn't put it in, perfect for me as designed with the resonator and small glass pack. Hard to put a number on it but it ups fun factor by a lot, more than you might think. Really...OK, by 50%, for me.

It's the only mod I will do.

As most say, getting the OEM off the hangers is the hard part, and I did squirt dish soap on them but getting it down into the hanger is difficult. But then putting the Superstreet back onto the hangers was EASY because then I could put soap all over both surfaces. So if I had to do it over again I would think a blunt tip syringe (cheap on Amazon) to squirt the soap all the way in before taking the OEM off would make the hard part easy too.

Dave in Stow, Ohio

Just the right exhaust note without being too loud or too much drone. Idle is basically silent, still. Overall I am very happy with the superstreet and would recommend it to anyone.

The install was less than 30 minutes. I'm not much of a mechanic and was initially intimidated, it turned out to be a straight forward install. The sound is incredible. The car feels a little peppery. I smile every time I run through the gears. Its louder than stock, but quiet at cruising speeds. This is money well spent!

Super easy install, huge weight savings and perfect sound for a driver that wants a more engaging sound without being obnoxious. The only downside is my mpg went down because I love hearing the exhaust at WOT. LOL.

Would recommend

I debated pulling the trigger on this for a few weeks as I read reviews and listened to dozens of YouTube videos of the various exhaust/muffler options. The analysis paralysis was real. Happy to report that I have *zero* regrets buying this one. It's relatively simple to install (~45 min by myself with no jack stands or ramps) and it sounds absolutely perfect. Buy this now and thank me later for the stupid grin every time you start it up and especially when you "give it the beans."

Beautiful exhaust note! Only took 35 minutes to remove stock muffler and install the new roadstersport superstreet setup. removed the baffle and it is a much quieter exhaust than I expected but sounds very nice. This is the muffler this car should come with from the factory. Very pleased!! Thank you for the great service and fast shipping!

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