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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 have included a number of features into our MX5 Miata 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.
We also 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 gasket....so our fit is as factory-like as possible.
Our collector outlet is 2.5 inches. For best 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.
TWO choices on what to do with the O2 sensors with our header. Choice ONE is buy our 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).
BRIAN'S APPLICATION NOTES: This is THE header for peak power on the NC with 2.0 and supercharger or 2.5 liter conversion. It is a bit too big for normal street driven 2.0 liter motor, using it on regular 2.0 street driven car will shift the torque curve much higher, and cause some loss of torque below about 3500 rpms and gains over the smaller headers above that point. Thus, we suggest our standard 1.6 inch primary version for normal 2.0 installs that are street driven because you want the low end torque for pulling out from stoplights, etc.
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.
Only test fit so far on MANUAL TRANSMISSION LHD USA cars.
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.