PART NUMBER: 11-1001
The factory converter for the 1999 to 2005 Miata is a welded in part of the midpipe (California 99-00 Miatas also have second converter in the header assembly).
Complete your highflow exhaust system with this midpipe...this is the best BOLT IN midpipe available for second generation Miatas and includes a highflow converter and built in resonator! Full 2.5 inches from tip to tip in all stainless steel.
ALL the mufflers we sell for 99-05 include only the muffler and not a midpipe (unlike the 90-97 choices). So if you want the flow to connect your new high flow header to your new high flow muffler here it is...for normally aspirated to supercharger or turbo (BUT does NOT fit MAZDASPEED). All stainless steel parts means years of quality performance and all the stainless parts have a lifetime warranty (300-cell ceramic catalytic converter used in all midpipes sold in 2012 or later now include a 5 yr/50,000 mile manufacturing defect warranty on its housing and 2 yr/25,000 mile manufacturing defect warranty on the internals).
FEDERAL VERSION, NOT CARB, NOT FOR SALE TO California residents. To prevent engine codes this midpipe has O2 connection for factory O2 sensor AFTER the converter (see forum instructions). Not for use with Racing Beat's lower rear chassis brace.
INSTALLATION: See Forum Installation Section! The slip joint in the middle of this item is your friend, lube it up and adjust length and clocking position as needed (if you ignore this note and shove both parts fully together you will make it all too short and that will cause contact with the differential).
INSTALL NOTES and CAUTION! Is your Ignition Coil weak or failing? The most common reason people buy this midpipe is that their Miata midpipe converter has failed after 50,000 or more miles. The owners too often assume the failure is simple old age, when in fact something else is failing. Failing items such as coils, fuel pressure regulators, spark plugs, valves, plug and ignition wires, and improper ECU calibrations, can cause the engine to misfire and dump raw fuel into the catalytic converter, which will cause over heating and a meltdown in the converter, and is not a manufacturing defect in the converter. If you simply replace the midpipe and don't fix the failing car then you can expect to quickly kill any replacement converter and that replacement will NOT be a warranty replacement. Therefore, please have your car professionally inspected and repaired BEFORE you install your new midpipe.
MIATA NA/NB 1999-2005
MIATA NA/NB 2001-2005
MIATA NA/NB 1999-2005
MIATA NA/NB 1999-2000
MIATA NA/NB 1990-2005
If you want to REALLY open up your nb exhaust, this is the way to do it. Finish is great. It sounds FANTASTIC paired with my borla catback and definitely sounds angry af when you lay in it. My biggest issue during install was a slight gasket mishap when pairing this with the oe header. I still had to use the oe gasket on the header side with their provided gasket to prevent leaks. Other than that install was pretty straight forward. Already preparing for the roadstersport header to finish off my build. Highly recommend!
The best exhaust you can buy for your NB Miata. I have the full Roadster Sport 4 muffler with the added mid pipe seen here. Fitment was perfect. The sound is incredible, it's a nice deep throaty tone. Absolutely no "fart" sounds. Loudness would be about 6/10, really tame under 3k, but a great sound above. And customer service was A+++. Brian helped me over the weekend with questions and finding what was best for me. I will be a repeat customer!
If you have the budget buy the entire system exhaust. There's simply NOTHING that will come close to this.
All in all, it DID bolt up. But it created an extreme amount of downward bend/tension on the FM turbo downpipe it was mated to. The flange angles would not mate up cleanly. Forcing the mating of the flanges with the bolts created larger downstream angles and more tension on each corresponding pipe. It was a large enough amount of tension and rubbing present that I had to take it to a muffler shop address with new cuts/welds. It's not all roadstersport's fault here, FM turbo downpipe didn't play well with it. I'm just making sure others who go this same route should expect to set aside some budget for custom fitting at the shop. Another fellow mx5 buddy experienced the same exact issue on his install this week as well.
Beautiful mid-pipe, cat and resonator. It sounds awesome. I have not stopped smiling since install. Paired with the Roadster sport 4 muffler w Hemholtz baffle and racing beat header. It is loud enough but enjoyable to ride and have a conversation at cruising speed. Resonator is not adjustable.
Installing this was very easy. "Best custom exhaust fit I have ever done" said my mechanic.
Seems to have added to the power noticeably when driving. Hard to tell driving on snow and ice this time of year.
Relatively easy to install, but no matter what adjustment I made, it's awful close to the differential, but after numerous test drives it does not touch. Overall, an excellent quality unit that I would recommend.
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