Good-Win Racing Mazda Performance Parts

RoadsterSport 4 Helmholtz Polished Stainless Steel Miata Exhaust Muffler


Miata 1990-2005 · Exhaust · Mufflers

Part Number: 11-1004H

Application: 1999-2005

Price: $329.00


RoadsterSport 4 Helmholtz Polished Stainless Steel Miata Exhaust Muffler
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FOURTH GENERATION UPDATE....A revolution in exhaust technology finally available for all 1999 through 2005 Miatas! Our new HELMHOLTZ exhaust system features an exclusive Helmholz main chamber that massively reduces the standing wave 'boominess' inside the exhaust system! Cuts the 'booming' frequencies of 120-130hz by over 35+db inside a top up Miata cabin which is a common source of complaints with aftermarket exhausts on the Miata. Result is all the FUN throaty sounds you want, without the drone other systems make that wears you out on long uphill and downhill sections of road.

Updated version of our favorite NB Muffler, now the ONLY choice on the market with Helmholtz chamber...AND adjustable sound level! YES, fits manual and automatic transmission. Built in solid 304 stainless steel and completely polished to a mirror finish, this high quality Miata exhaust is our only choice that incorporates a baffle insert that gives YOU some control over the final sound level (baffle in is only about 15% more sound than stock, baffle out is about 25% more sound than you always have a choice for those longer trips). Weight is lighter than factory.

For those that want even more sound add our highflow Miata midpipe for more flow and another 10% more sound.

This latest version of our best selling Miata exhaust has both baffle included and a double walled tip for years of lasting good looks while giving you control over the final sound level. And, you always have the option of our packed baffles which are sold here separately.

LIFETIME WARRANTY, this Miata muffler is made with pride in the USA. YES, includes gasket and hardware needed for install.

*** Product images may differ from actual product appearance ***


Brian, just wanted tyou to know you've got another highly satisfied customer. I got my RoadstersportIII muffler on Friday, installed it in 20 minutes, looks and sounds awesome. I like the baffles out!! My new tires/wheels came Saturday, just got them on and test drove them. Fantastic!! And how they look--- just what I was after. I will add the front "mud flap" that looks like the rear one, for some stone protection, but the offset was just what I was working for. I'd love to send you some pictures for your photo gallery. If you'll send an adress via e-mail, I'll send some high-res photos showing clearances and side profiles, etc. The graphite spokes and polished rims really set well on my black car. Thanks again, me and my wallet will be back!!

-- Ken

Thanks for such speedy and great service.

-- Richard H.