RoadsterSport MAX Power 1.8 Inch NC Stainless Steel Header for MX5
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RoadsterSport MAX Power 1.8 Inch NC Stainless Steel Header


PART NUMBER: 61-1979


Reg. Price: $819.00

Sale Price: $649.00

Oxygen Sensor Extension Wires


Due to EPA restrictions, this product cannot be shipped to California.


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

Reg. Price: $819.00

Sale Price: $649.00

Oxygen Sensor Extension Wires


Due to EPA restrictions, this product cannot be shipped to California.


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


Our famous RoadsterSport MAX Power Header with MONSTER 1.875 inch primaries has become the standard for big power NC builds. Particularly helpful for those with superchargers and 2.5 liter conversions, but testing has shown it is perfect for 2.0L engines too!

2022 UPDATES: Generation 2 of this header improves even further on the best header on the market for the NC:
- Now beautifully TIG welded for an even cleaner finish
- Now comes with a donut gasket for the connection to the midpipe at no extra cost!
- Improved clearance to the passenger side engine mount bracket - Now even compatible with our engine drop brackets that lower the motor a half inch!

Look at those smooth curves! Notice you don't see 6 welded sections for each primary like so many lesser headers that are made from cut pieces of standard radius pipe and straights. Instead, where possible ultra SMOOTH all mandrel bent tube is used here to keep flow as clean as possible. Sexy all T304 polished stainless steel is formed into massive 1.8 inch primaries for max power...with a lifetime warranty!

We put incredible effort into making the exit at the collector as smooth and perfect as we can get it because this collection point is the KEY to good header flow and we had to make sure this was done as perfect as possible. Note we use the factory collector our fit is as factory-like as possible.

Our collector outlet is 2.5 inches. 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.


Header comes with new "donut" gasket for the header to midpipe connection. Does NOT come with a gasket for header to engine connection - you reuse your factory gasket there - that gasket is a metal gasket usually good for the lifetime of the car unless you damage yours.


Several options on what to do with the O2 sensors with our header. Read below for options A, B and C. Optional oxygen sensor wire extension cables are available as an add-on option with this header. Adding ONE wire extension gets you one long wire extension to move the secondary oxygen sensor to the midpipe as described in option B below. Adding TWO wire extensions gets you one long and one short wire extension for moving both primary and secondary oxygen sensors down to the midpipe as described in option A below.

A) Buy our midpipe and our two wiring extensions available here for simple plug and play install. Our midpipes are designed to take both O2 sensors, and includes two O2 sensor connections for that - one before the midpipe's converter and one after the midpipe's converter to help avoid a code. Buy BOTH of our extensions for that option.

B) Second choice and most common choice is first sensor in the header and second sensor in our midpipe after the converter, which will also avoid a code. For install in the midpipe of both sensors you need both O2 extension cords, but if you put the first sensor in the header you only need an extension for the second sensor. The first sensor will reach header connection but you may have to follow the wires back to the harness and use a razor blade to clear some sheath which has them gathered shorter than they actually are.

C) Third choice is to put BOTH sensors in the header, which will cause a code unless your tuner turns off the code caused by having the second sensor in the header. You don't need any wiring extensions for that option (sensors will reach header connection but you may have to follow their wires back to the harness and use a razor blade to clear some sheath which has them gathered shorter than they actually are).


There are TWO oxygen sensor bungs provided by the outlet flange on this header. The header ships with plugs loosely pre-installed in both bungs. Remove a plug to install an o2 sensor where you need it according to the sensor configuration you're running on your particular car (various options A/B/C described above), and where you are not installing a sensor be sure to TIGHTEN the plug there before install.

CARB NOTICE: Installing this header in the 2006 through 2015 MX5 Miata means removing the first catalytic converter which means this header will NEVER be a California street legal header, never be CARB approved (and therefore legal in California for off road use only). Note that there are states in addition to California that now follow the California model and require CARB compliance, please check the rules of your state before ordering, in some states this setup is legal only for race cars and may never be used on public highway. Sorry, we will not ship these to residents of California.

BRIAN'S APPLICATION NOTES: This is THE header for peak power on the NC with 2.0 and supercharger or 2.5 liter conversion. For a long time we suspected it was a bit big for normal street driven 2.0 liter motors but customer dyno work has more recently shown that it beats our smaller 1.6 inch primary header at all points of the curve.

We assume Left Hand Drive fitment only, we have not installed this big header on cars other than USA/Canada versions.

The first converter is also a pretty good resonator so understand that installation of any header will raise the exhaust sound level a good 20%. Therefore, we strongly recommend the RoadsterSport Q muffler with any header change because it was designed to handle the sound level of the header, and our RoadsterSport Helmholtz midpipe tunes the final sound result for drone free fun.

YES this header fits with the automatic transmission with a bit of grinding. There is a minor clearance issue between the edge of the header's bottom flange and the auto transmission. Some grinding needs to be done to knock the corner of the flange down a hair and then everything will fit.

INSTRUCTIONS: Read full installation hints and notes in our forum Installation Instruction Section! ---

Dyno shows improvement in power on our supercharged 2007 2.0 liter as compared with 1.6 inch version of same header. This was comparison purely on flow, no changes to tune. With greater flow even more timing could be added to make this difference MUCH greater.



Customer Reviews

RoadsterSport MAX Power 1.8 Inch NC Stainless Steel Header

This thing is gorgeous! Amazing welds, solid build! This was my last step of the complete exhaust. I now have this, the mid-pipe, and the Super-Q exhaust. I must say prior to updating my tune with Mike @ Xero things were pretty good. Nice sound, no drone. But once you have some milage on this and the corrected tune for the flow this offers, this totally wakes up the car. It's a beast now. Running like a champ. I was skeptical about the tone changing over time, but I'll be the first to say, this setup has mellowed out nicely. What a great-sounding setup. Pulls like a train. Yeah, hop on this.......

Really great piece. I have the Roadstersport Midpipe and Race muffler, so I was going for a very loud result...and I got it. Sounds amazing and really does up the torque above 4500, which is how I drive normally on the street as well as the track. As the other reviewer said, I absolutely HAD to shift my alternator forward and temporarily disconnect the coolant line above the header for installation. Not a big deal, the instructions tell you how. BUT in my case, even though I had the goodwin midpipe, I still needed BOTH of the O2 sensor extensions. No matter what I did, the first O2 sensor would not reach the header. So I ended up having to purchase both extensions, and just put both sensors in the midpipe.

Goodwin is amazing with response time for questions -- any issues, and they email you right back. Thats a lot more than I can say for our other Miata shops online.

This header sounds great. I put this on after breaking in my 2.5L engine and I couldn't be happier. Doing this task on my own for the first time, however, was a pain. I did have an issue with the connection to the midpipe. The connection flange was turned approx. 5 degrees clockwise making the midpipe and header not connect properly, and I had to spend a good hour or two just on tweaking and manipulating the midpipe to twist just enough for the connection to be made.

I currently have an ISR performance muffler delete with the stock midpipe and this header. The sound outside of the car is not as loud as you perceive it from inside the car as a side note. This is where I believe the Helmholtz midpipe will come into play, and will probably be my next buy.

My own personal installation note:

This header WILL NOT go in without either removing the alternator, or tilting it forward by removing the top bolt and the bottom, rear bolt. I opted for the latter option, but needed to maneuver the AC lines and the Coolant hose out of the way. Removal and installation time for myself on my own (First time ever doing this) was about 4-5 hours with about 2 hours being me tweaking the midpipe.

Overall great header, might have just been a one-off on my flange.

Did a 2.5 upgrade installed header along the way perfect fit well made header.

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