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. 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. Our experience is that owners of Automatic transmissions prefer any of our SuperQ choices. This is an aggressive sounding muffler for those who like to go for the redline often!

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.


Stubby Antenna
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MIATA MX5-ND 2016-2023


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Customer Reviews

RoadsterSport SuperStreet

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!

I just installed the roadster sport on my 2022 mx5, this has made such a difference in the way the car sounds thru the the rev range, I had a Borla sport complete garbage, this muffler feels like I have a slight more power thru the range, I would highly recommend this for a improvement over stock.

This is exactly the sound I wanted to hear from the exhaust, and the engineering they did on this is excellent. When puttering around suburban streets or driving unhappily in dense traffic, it seems no louder than the stock exhaust - just a lower dominant frequency. When you tip heavily into the throttle it's a totally different beast, with as good of a roar as you could expect from four small cylinders. Coming off of heavy throttle, there's even a touch of burble in there. My wife was afraid that it'd be unpleasantly noisy, but like me, is pleasantly surprised.

What I didn't much care for was the baffle that comes with this muffler. It doesn't take the volume down much, and my butt-o-meter told me, when I took the baffle out, that it's also robbing a bit of power. Car behaves very differently on idle, and performs quite differently - read better, faster - if I'm punching throttle hard clearing an apex without the baffle. Several friends in the Miata club where I live have the RSSS muffler, and are of the same conclusion - everyone's running without the baffle. Several are wishing the'd bought the full on race since the volume level really isn't bad - a fraction of what the typical F150, Mustang, or Harley aftermarket exhausts put out.

It did seem to have just as much of a drone at highway speeds as the stock muffler - again just a different frequency. Not awful, just annoying. I got the glass packed baffle - see my review there - and my friends with the RSSS mufflers are all clamoring to borrow it for a few days after hearing my car with that in. Drone muted. Roar and burble maintained.

Love this exhaust. Have recommended to many seeking to lose they whiny nasal stock exhaust tone.

After a fair amount of online research into cat-back exhaust options for the MX-5 ND2's ( & YouTube mostly), I decided on the Good-Win Racing RoadsterSport SuperStreet exhaust. I couldn't be happier with the decision!

Price was fair, packaging for cross country transport, build quality and ease of installation were great, and the speed of delivery was quick.

I'm not sure how the other options from Good-Win Racing sound in person, but this one sounds perfect for my needs. More aggressive sounding on start-up & idle, not too loud cruising on the highway, and just loud and deep enough to sound like "fun" when revving it out.

***Installation was super easy and quick. Just the right sound with baffle in or baffle out .
I bought the packed baffle also for when I take long Highway trips , perfect sound , no droning . The Complete muffler is excellent .Quality construction. Great follow up with technicians too .The only issue is in town you think you're getting much much less gas mileage but you're not you're just putting your foot deeper in it lol, you want to go fast and hear it. Second gear slowing down, deep throaty sound is amazing!!! Order it Now, you will be happy.

I bought this exhaust because the stock muffler was too quiet for a sports car. I installed it myself in a few minutes without jacking up the car. I've run it both with and without the included "mini-baffle" and prefer that baffle out. I don't think it's too loud at all but if you are sensitive to those things then this is not your muffler. If, on the other hand, you like to chase the redline, this is definitely a great muffler. Highly recommended.

The parts arrived quickly and a piece of cake to install. Granted, the car only had 1500 miles on it, so it was easy to take everything apart. The total installation took less than 45 minutes. I sprayed the rubber isolators with WD40, and they slipped right off. The sound is exactly what I was looking for and the wife enjoys it as well because I now rarely get to drive it thanks to all the Goodwin goodies.

Solo install in my garage in about 40 minutes was super simple and easy. The tone is deep without any droning. I hear no hard edges on the tone either. It's fairly quiet on part throttle and during cruising with only a background purring at highway speeds. Go hard on throttle and run it to redline if you want to induce a lasting grin. What an amazing product.

What a GREAT exhaust! Installed without the baffle... perfect... sounds awesome!
Install is about as easy as it gets, took maybe 15 minutes.

Absolutely perfect. I wanted to change the exhaust note without being an obnoxious boy racer and this was exactly what I wanted. Looks great too.

We know inline 4 bangers don't typically have the best exhaust sound, but we love our Miatas and this is a relatively cheap, great looking, light and decent sounding exhaust. Installed it in my driveway in an hour. Tried removing the baffle, and, YMMV but it was waaaay too loud for me that way so put it back and love it. Buy it! You'll love it too.

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