MX-5 Miata RoadsterSport HELMHOLTZ Midpipe with Converter 2006-2015
A revolution in exhaust technology finally in a Mazda MX-5 Miata application, this midpipe features an exclusive Helmholtz Resonator that massively reduces the standing wave inside the exhaust system, reducing the 'booming' frequencies of 120-130hz by 48+db inside a top up Miata cabin which is a common source of complaints with aftermarket exhausts on the MX-5.
Note it is very dual personality because the effect of the Helmholtz is very frequency specific such that under decel it is mild and quiet, yet when you push hard toward redline it sounds exotic and racy. With the top down lots of fun throaty burble, but dramatically more tame when the top is up. In brief, FUN when you want it, and mild when just cruising.
Designed as a bolt-on replacement for the factory midpipe to carry higher flow all the way out any of our RoadsterSport mufflers. Designed and tuned to work best with our RoadsterSport headers and mufflers. Simple Bolt on.
INCLUDES TWO O2 SENSOR CONNECTIONS which gives YOU the option to later add our RoadsterSport headers and avoid engine codes (by using our O2 plug and play extension cords to relocate the factory O2 sensors to before and after the converter in this midpipe).
All stainless steel construction for years of driving pleasure. This MX5 Miata midpipe is larger diameter than stock for superior flow, particularly when matched to our headers. Uses high quality SPUN catalytic converter with metal core (despite presence of converter this unit is not CARB approved...which makes it legal in California only for off-road/race track use).
This midpipe will raise the final sound level because of the higher flow larger diameter tubing and because the Helmholtz is frequency specific in operation.
SORRY, NOT CARB APPROVED FOR CALIFORNIA RESIDENTS.
STR LEGAL under Class Rules Update 2012. Pursuant to SCCA 14.10.E: our cat fits entirely in the space that the factory cat occupied pursuant to SCCA 14.10.E....and Magnaflow certifies the core for use in any application <6.2L and 6000 pounds. Core has 25,000 mile manufacturing defect warranty (no core warranty for boosted or track cars), and the rest (including housings) are stainless and include a lifetime warranty.
APPLICATION NOTES: It's a serious revolution in Miata exhausts, makes just about any muffler combination MUCH more fun. I never seriously considered less than our RoadsterSport SuperQ as appropriate for the NC Generation Miata AFTER adding any header but this midpipe makes ALL our choices MUCH more fun, particularly after header install. NONETHELESS, this midpipe is NOT for the timid. Why? Because the nature of this style of resonator is that the targeted frequencies are much LOWER volume and other frequencies not targeted are much LOUDER than with our standard midpipe. This dual nature of the performance means when you are hard on the throttle it is LOUDER than with our standard midpipe, but on decel or running in the low rpm ranges where these cars tend to drone this setup is much quieter than our standard midpipe. You get all the racy fun, without the drone, but beware that racy fun never shuts up if you use a heavy foot! Therefore, think about what you really want, who YOU really are! If you don't mind some attention for the throaty racing sounds when on the throttle and you just want a midpipe that kills drone on decel and when cruising then this is your dream NC Miata Midpipe.
A little on the science, we targeted 120-130 hertz range which is where most folks report uncomfortable 'drone' or 'boominess' and got a total of 48 decibel max drop right at the 125 hertz level...which is a MASSIVE reduction. Nonetheless, looking at broader range we get an average 20 decibel drop from 115 to 138 hertz with reasonable 8 decibel drop in the ranges of 95 to 115 and 138 to 180 hertz.