We are proud to offer our PLUG AND PLAY RoadsterSport Street catted header, all sensors stay in factory locations! This is the most torque you can buy in a catted MX5 Miata header. All Stainless Steel 1.6 inch primaries and proudly made here in the USA. 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 a Plug And Play MX5 Miata header with converter that is 49 state legal! Sorry, we cannot ship these to residents of California.
MX5 Miata Street Header features:
-Longer, equal length runners
-High-flow 5" round, 200cpi Ceramic Core Catalytic Converter
-EPA and OBD2 compliant converter, 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. But not CARB approved so it is not legal for street and/or highway driving in California.
-Bolt-in design for MANUAL TRANSMISSION (see our forum header install thread for details of installation on automatic transmission).
-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 manufacturing defect warranty (normally aspirated cars only, NOT recommended for supercharged cars or heavy autocross/track use), the rest is all stainless steel and has a LIFETIME warranty, even the flanges!
Currently for Manual Transmission only (a professional can install on the automatic but it requires re-engineering the cooling line layout and modification to the bell housing). Also, sorry to our Australian customers but this fits Left Hand Drive only.
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.
**Oversized products like these typically only ship domestic to the contiguous united states, if you order outside of that we will calculate shipping upon processing the order and send an invoice for the total.
1 Review
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Raodstersport Street header
I had already put an aftermarket muffler on my NC, so the next thing was the ceramic coated version of the Roadstersport Street header. Installation took me about 9 hours total, but partly that was because I was being cautious to make sure I got everything right. Old one coming out wasn’t too bad, once I took off all of the OEM heat shields, including the lower ones. Doing that, I found I could get it out without moving the alternator, as was suggested in most of the online installation instructions.
New one going in was where I had some trial and error. Turned out I could get the new one in, again without moving the alternator, if I installed only the upper O2 sensor first, then put the header in, then installed the lower O2 sensor and the two studs that connect to the midpipe. I also did not need the O2 extension wire after I freed up some of the extra length in the factory leads.
The sound is just what I wanted; that first catalytic converter acts like a resonator, and the result is really no louder than it was with the factory exhaust manifold.
Later I bought the Versatuner package, and retuned the car for the header. My butt dyno isn’t that well calibrated, but I think I do feel a little more oomph after this installation, particularly in the mid-range, like when hitting it to pass someone. The retune also bumped the rev limiter up from 7200 to 7500rpm. Overall an interesting installation project, and a good result.
