Innovative Mounts 113550-75A Replacement Engine Mount Kit for 1999-2000 Mazda

Vehicle Fitment

• 1999-2000 Mazda MX-5 Miata (NB1 chassis | 1.8L BP-4W)
• Compatible with any NA or NB chassis fitted with the 1999-2000 MX-5 1.8L engine

Fitment Notes

• Designed for the NB1-generation MX-5 Miata (1999-2000) equipped with the 1.8L BP-4W engine. Also fits any earlier NA chassis that has been fitted with the 1999-2000 1.8L motor - mount fitment follows the engine, not the chassis year.
• Does not fit the 2001-2005 NB2 Miata (1.8L BP-Z3 engine) - that application uses part number 113450. Does not fit the 1994-1997 NA Miata (1.8L BP-4W different calibration) - that application uses part number 113150. Does not fit the 1990-1993 NA Miata (1.6L B6-ZE engine) or the 2006-2015 NC generation.
• Does not include a transmission mount. This kit covers the left-hand (LH) and right-hand (RH) engine side mounts only. The factory transmission mount is retained.
• Uses stock OEM hardware - no additional hardware is included. Installer will reuse the factory bolts throughout.
• No notching, trimming, or hood modifications required for installation.
• Height-adjustable design: the mount allows the engine to be raised or lowered by 3/8" from stock position by selecting the appropriate mounting point.
• 75A durometer polyurethane is the performance street bushing option, recommended for builds producing 250-400 hp. Owners of lightly modified street Miatas under 250 hp seeking the most street-friendly NVH levels should consider the 60A (113550-60A). Dedicated track or high-output builds above 400 hp should consider the 85A (113550-85A) or 95A (113550-95A).
• Once installed and bolted down, mounts cannot be returned or exchanged - bolt impressions will be visible on the bushing. Confirm fitment before installation.
• Professional installation by a mechanic or automotive specialist is strongly recommended.

Features

• Direct factory/OEM replacement fitment - bolt-on replacement for the stock rubber-filled engine mounts, requiring no chassis modification or fabrication
• 75A polyurethane (black) bushings provide a significant step up in engine stability and drivetrain response over both the OEM fluid-filled mounts and the softer 60A variant - recommended for forced induction, high-torque, and performance builds producing 250-400 hp
• At 75A, the bushing compound strikes the balance between performance driving rigidity and acceptable street NVH - more vibration than stock or 60A, but still manageable for dual-purpose street/track use
• Unique no-tear polyurethane bushing formula resists degradation from engine heat, oil, and the torsional loads generated by performance driving - engineered to outlast OEM rubber mounts by a significant margin
• By eliminating the factory fluid-filled rubber mounts, these Innovative mounts reduce engine movement under acceleration and braking, improving shifter feel, reducing wheel hop, and providing more consistent throttle response
• Height-adjustable mounting: select from two mount positions to raise the engine 3/8" above stock - useful for small engine bay clearance adjustments on modified builds without requiring hood trimming
• Black powder-coated solid steel mount body provides long-term corrosion resistance and structural durability far beyond the thin-gauge stamped steel of OEM mounts
• CAD/CAM designed and stress analyzed at Innovative's North Carolina manufacturing facility for precise fitment and structural reliability under performance loading
• Manufactured entirely in the USA - designed, cut, bent, welded, powder coated, finished, and packaged at Innovative's facility in North Carolina
• Covered by Innovative Mounts' Lifetime Warranty against defects in material and workmanship when purchased through an authorized dealer

Specifications

• Part Number: 113550-75A
• Brand: Innovative Mounts
• Application: 1999-2000 Mazda MX-5 Miata NB1 / 1.8L BP-4W (also fits any NA/NB chassis with 99-00 1.8L engine)
• Mount Type: Replacement Engine Side Mounts (LH + RH)
• Mount Body Construction: Black Powder-Coated Solid Steel
• Bushing Material: Polyurethane
• Bushing Durometer: 75A (Black)
• Recommended HP Range: 250-400 HP
• Bushing Design: No-Tear Vibration Minimizing
• Hardware: Uses Stock / OEM Hardware (not included)
• Height Adjustment: Adjustable ±3/8" from stock position
• Hood Modification Required: None
• Design: CAD/CAM Designed, Stress Analyzed
• Made in USA (North Carolina)
• Warranty: Lifetime Warranty (authorized dealer purchase)

Included Components

• 1x Left-Hand (LH) Engine Side Mount - Black Steel with 75A Black Polyurethane Bushings
• 1x Right-Hand (RH) Engine Side Mount - Black Steel with 75A Black Polyurethane Bushings
• Note: OEM hardware required for installation - not included in kit

Product Description

The Innovative Mounts 113550-75A is a direct-replacement engine mount kit for the 1999-2000 Mazda MX-5 Miata NB1 equipped with the 1.8L BP-4W four-cylinder engine. It replaces the factory fluid-filled rubber side mounts with solid steel mounts fitted with 75A durometer polyurethane bushings - a performance street upgrade specifically rated for builds producing 250-400 horsepower. The kit includes the left-hand and right-hand engine side mounts only; the factory transmission mount is retained. Owners of the 2001-2005 NB2 Miata should use part number 113450-75A instead.

The 75A bushing compound is the step up from the entry-level 60A (street/daily use, up to 250 hp) and is designed for Miata builds with meaningful power modifications - forced induction, high-flow naturally aspirated builds, or any application where the 60A's lighter engagement leaves too much drivetrain slop under load. At 75A, the polyurethane holds the engine more firmly in place under acceleration and corner exit loads, translating directly into improved shifter feel, reduced wheel hop, and more predictable throttle response in performance driving situations. The NVH increase over 60A is noticeable - particularly at idle on cold starts - but manageable for dual-purpose street and track use. Owners seeking the absolute minimum NVH impact on a street-only build should consider the 60A variant (113550-60A).

A practical feature of this kit is its built-in height adjustability - the two mount bolt positions allow the engine to be raised 3/8" above stock height without any hood trimming or clearance issues, useful for builders making minor drivetrain height corrections. All installation uses the factory OEM hardware, which is not included in the kit. Mounts cannot be returned after installation once bolt impressions are visible. Made in North Carolina and backed by Innovative Mounts' Lifetime Warranty when purchased through an authorized dealer.