Goodwin Racing RoadsterSport SuperStreet Twin Tip - ND
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 13.9 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:
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 is 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 under 14 pounds, a nice savings over the 21 pound factory muffler.
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.
The SOUND level is Adjustable by YOU, INCLUDES removeable 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 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. 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.
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. This is an aggressive sounding muffler when you put your foot deeper in the gas! However, if our RoadsterSport SuperQ is 10 to 15% more sound than stock (depending on use of removable baffle), and our ND RACE is a full 50 to 55% more sound than stock when on throttle, and this ND STREET is the middle choice at about 35% over stock sound level when on throttle hard, though perhaps just 15% over stock when cruising home in high gear and low rpms. Works well with stock midpipe and our RoadsterSport midpipe, NOT for customers adding a header (see our SuperQ for