Good-Win Racing Mazda Performance Parts




Miata MX5 2006-2015 · Exhaust

Part Number: 61-1155C

Application: 2006-2015

Price: $799.00


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Already the most torque you can buy in a catted MX5 Miata header, our new All Stainless Steel MX5 ROADSTERSPORT STREET HEADER just got even better with this Limited Edition Ceramic Coating!

BRIAN'S NOTES ON CERAMIC COATING. Frankly, it is usually only the mild steel headers that are ceramic coated and I had always suspected that the main reason was to slow down the inevitable rust that a mild steel header will suffer over time. Since this header is already made in ALL STAINLESS STEEL, it does not need ceramic coating for rust prevention. That left the pure question of whether or not we could really find additional torque with the ceramic coating to justify the costs. After lots of testing the answer turned out to be YES, at the points on the curve where our plain stainless header gets 12hp this coated version is consistently two points stronger, with peak hp up yet another 2 more to 160 hp at the wheels compared with 158 at the wheels for regular stainless version of this header (new dyno graph below), and a consistent 3+ foot pounds of torque from mid range to redline over the regular stainless version of this header.

See our forum MX5 PRHT Project and Dyno thread for many more details on development history, pictures of prototypes, and dyno work. A great choice for street customers looking for an MX5 Miata header with converter that is 49 state legal!

MX5 Miata Street Header features:
-Longer, equal length runners
-High-flow 5" round, 200cpi Ceramic Core Catalytic Converter
-49 state legal cat (EPA and OBD2 compliant, but NOT CARB APPROVED for California, the Carsound 99659HM core is an EPA certified converter covering up-to 6.2L/6375 lbs so it easily handles the flow of our performance header while still delivering clean tailpipe emissions)
-Bolt-in design
-Bolts to RoadsterSport MX5 Midpipe...or stock MX5 midpipe. Also saves weight, factory header assembly is 15.2 pounds and this RoadsterSport MX5 Street Header with converter is just 11 pounds! Converter has two year warranty (normally aspirated street cars only, NOT recommended for supercharged or track driven cars), the ceramic coating by Techline has a three year warranty, and the stainless steel structure has a LIFETIME warranty, even the flanges!

Read full installation hints and notes in our forum Installation Instruction Section! --- CLICK HERE TO READ MORE.

Easy Plug and Play for Manual Transmission only (a professional can install it on the automatic but that install requires re-engineering the cooling line layout and modification to the bell housing). SEE OUR FORUM INSTALLATION INSTRUCTIONS.

We have included a number of extra features into our MX5 Miata Street Header which we believe customers will appreciate. We CNC machine the main flange to match the factory unit, including the bolt hole flange area thicknesses so that we are precisely replicating the factory fit to the head in terms of thread depth and space, etc.

Our collector outlet is 2.5 inches. Curiously, the factory outlet is ALSO 2.5 inches and then the factory exhaust chokes down after that point. For best HIGH RPM performance customers should match our header with our midpipe and exhaust so they are running 2.5 inches of flow all the way...but our header will bolt in place of the factory header and connect perfectly to the factory midpipe for better performance from idle to redline.

Note the optional extension cords below, which many find unnecessary if they release some O2 wires from the factory harness bracket (just follow the O2 cords back until you reach that bracket and this will become obvious).

PICTURE OF FACTORY MX5 HEADER BELOW, Note the pinch point where the factory header suffers the primaries pinched in half, circled in red below. That pinch point chokes the power this Miata 2.0 motor can otherwise make. Our Roadstersport Street MX5 Header eliminates that pinch point, extends the primary length to max torque gains, while retaining a high efficiency converter.

BRIAN'S APPLICATION NOTES: We pushed the converter as far down against the lower flange as possible to maximize the length of our primaries to maximize the torque gains. Dyno Below shows results of configuration we expect most will run (RoadsterSport Street Header with Roadstersport Q midpipe and Roadstersport Q muffler). Low line best results with stock intake and stock exhaust, high line is results with this Roadstersport Street Header, Roadstersport Midpipe and Roadstersport Q exhaust. We expect many will leave factory midpipe in place and use this header with our Q on the end (factory midpipe just a little smaller in diameter and we expect that keeping the factory midpipe would give similar results through the low and mid range and give up just a bit toward the high RPM range).

Notice O2 Bung BEFORE and AFTER Converter so you can keep your factory O2 Sensors inline and prevent engine codes.

First dyno below shows our uncoated version against stock header, notice that the gains in torque are strongest at the low rpm range but extend through the mid range and all the way to redline, that's a torque improvement you can feel every time you pull away from a stop and every time you grab a higher gear! These are results of bolt-on only, adding our MotoEast Tune would further improve the results. Visit our Forum for more details on development of this item and our 2012 PRHT Project Car

And this second dyno chart shows the ADDITIONAL gains of the ceramic coated version over the uncoated version, we hit 160 hp at the wheels with consistent torque improvement of 3 to 4 foot pounds from the midrange up to redline.

Or visit our 2012 PRHT Project Car Blog.

Listen to the full combo below of our MX5 Miata RoadsterSport Street Header, Midpipe and RoadsterSport Q Exhaust.

*** Product images may differ from actual product appearance ***


Hi There Good-Win Racing. I just wanted to thank you guys so much for the great customer service and quality parts. My 91 MX-5 is running awesome thanks to the parts I put on it from your website, racing beat sway bars, racing beat endlinks, racing beat muffler, magnaflow catalytic con, shifter parts, and a few more. Thank you so much for making your website so knowledgeable and easy to get all these awesome MX-5 parts. My MX-5 handles, drives, and sounds awesome with all the new parts, Thanks a Million!! I look forward to ordering a new exedy performance clutch and light weight flywheel from Good-Win Racing in a couple months.

-- Sean

Hey Brian, Recieved my Borla Dual Muffler Sport today from Fedex, and installed it in about 30-45 minutes. An Outstanding product with absolutely no drone throughout the power band, it sounds powerful, not at all like one of the ricey "fart tubes" that can be found elsewhere online. It has perfect like OEM fitment. Great prices, and great products. Product was shipped promptly and arrived as ordered. Would buy again!

-- Jake