ISR Performance Circuit Spec Exhaust - Miata ND1 2016-18

The ISR Performance Circuit Spec Exhaust is a three-piece catback exhaust for the 2016-2018 Mazda Miata ND1 (NA chassis, pre-facelift). 2.5 inch brushed stainless piping with V-band joints, ending in a polished stainless muffler with a 4 inch tip. Designed for circuit and track use with a clean, modular construction that breaks down easily for transport.

What It Does

The factory ND1 Miata exhaust is restrictive and tuned for quiet operation. The Circuit Spec replaces it with a free-flowing 2.5 inch stainless system that opens up exhaust flow, drops weight, and delivers a deeper, more aggressive tone. The three-piece design with V-band mid joints means the exhaust separates into manageable sections for transport and easier installation than a one-piece catback.

The polished muffler with 4 inch tip gives the back of the car a clean track-focused look that fits the ND Miata's existing aesthetic without going over the top.

Critical Fitment

USDM ND1 manual transmission only. This exhaust will NOT work on:

• Euro-market ND Miatas (different exhaust routing and emissions equipment)
• Automatic transmission ND Miatas

Fitment

• 2016-2018 Mazda Miata ND1 (USDM, manual transmission)

Not tested or designed for the ND2 (2019+ facelift, higher-output engine). Confirm your car is ND1 before ordering.

What's in the Box

• 1x 2-bolt front pipe with resonator (bolts to header with V-band rear flange)
• 1x V-band mid pipe with 2-bolt rear flange (bolts to muffler section)
• 1x Muffler section with 4 inch tip
• 1x V-band clamp
• 1x 2-bolt 2.5 inch exhaust gasket
• 2x Bolts
• 2x Nuts

Product Details

Brand: ISR Performance

Part Number: IS-CSEXH-ND

Type: Catback Circuit Spec Exhaust

Vehicle Fitment: 2016-2018 Mazda Miata ND1 (USDM, manual transmission)

Generation Restriction: ND1 only - not confirmed for ND2 (2019+)

Market Restriction: USDM only - NOT for Euro models

Transmission Restriction: Manual only - NOT for automatic

Material: Stainless steel

Finish: Brushed stainless piping, polished stainless muffler

Piping Diameter: 2.5 inch

Tip Diameter: 4 inch, polished

Construction: 3-piece with V-band mid joints (resonator + V-band mid + muffler)

Application: Track and circuit use

Sold: Complete catback with hardware

Legality: Off-road and competition use only