Good-Win Racing RoadsterSport MAX Power 1.8 Inch MX5 Exhaust Header for 06-15 MX5

The famous RoadsterSport MAX Power Header...now with MONSTER 1.875 inch primaries for customers with 2.5 liter conversions and supercharged 2.0 liter motors!  Works on stock 2.0 liter engines as well.

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!

Good-win has included a number of features into this MX5 Miata header which we believe customers will appreciate. They CNC machine the main flange to match the factory unit, including the bolt hole flange area thicknesses so that they precisely replicating the factory fit to the head in terms of thread depth and space, etc.

They also put incredible effort into making the exit at the collector as smooth and perfect as possible because this collection point is the KEY to good header flow and they made sure this was done as perfect as possible. Note they use the factory collector gasket....so the fit is as factory-like as possible.

The collector outlet is 2.5 inches. For best performance customers should match this header with the RoadsterSport midpipe and exhaust so they are running 2.5 inches of flow all the way...but this header will bolt in place of the factory header and connect perfectly to the factory midpipe.

TWO choices on what to do with the O2 sensors with this header. Choice ONE is buy the RoadsterSport midpipe which is designed to take both O2 sensors...and includes two O2 sensor connections...one before the midpipe's converter and one after the midpipe's converter to help avoid a code by simulating the factory installation before (and this setup keeps flow as clean as possible in the critical collector). 

Second 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. Third choice is first sensor in the header and second sensor in our midpipe after the converter, which will avoid a code. For install in the midpipe of both sensors you need both O2 extension cords, if you put first sensor in the header you only need extension for the second sensor, put both sensors in the header and you don't need any extension cords but do need your Tuner to shut off code from second sensor.

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).

GOOD-WIN'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. This header is BIG, it will NOT fit with AWR lowering mounts, our lowering brackets, there is just no room remaining to lower the motor with this big pipe header. We usually use our RoadsterSport engine mounts with this header.

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 this header change because it was designed to handle the sound level of the header, and the RoadsterSport Helmholtz midpipe tunes the final sound result for drone free fun.

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 their RoadsterSport Helmholtz midpipe tunes the final sound result for drone free fun.

Only test fit so far on MANUAL TRANSMISSION LHD USA cars.

Dyno shows improvement in power on a 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.

FITMENT NOTES: 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.