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1990–2005 Mazda MX-5 Miata (NA & NB) chassis

This car is a unibody, so there's no separate frame to replace. The way to modernize it is to upgrade the original suspension, stiffen the body shell and fix the known weak spots.

Upgrade the original chassis

How it's built
Steel unibody
Front suspension
Double wishbone suspension with coil-over dampers and an anti-roll bar. Rack-and-pinion steering, power assisted on most cars.
Rear suspension
Double wishbone independent rear suspension on a subframe tied to the front by an aluminum power plant frame. Differential options were open, viscous limited-slip or Torsen limited-slip depending on year and trim.
Weak spots
Rocker panels rust from clogged drain holes, rear wheel arches rust, and NB front frame rails are a known rust point. Bushings and dampers are usually worn, and the open-top body flexes noticeably.

Stiffening the body or frame? We list 4 kits for this car, such as frame rails, subframe connectors and braces, on its Chassis stiffening page.

Suspension and steering kits for the original chassis

AreaKitWhat it doesPrice
Complete kit Flyin' Miata Flyin' Miata Koni Stage 1 suspension package (NA chassis) Koni-based spring and damper package for 1990-97 NA. $1,358 from Source
Complete kit Flyin' Miata Flyin' Miata Koni Stage 1 suspension package (NB chassis) Koni-based spring and damper package for 1999-05 NB. $1,428 Source
Coilovers Flyin' Miata Flyin Miata FOX suspension for NA FOX coilover suspension for NA; NB version listed from $1,750.00. $1,870.11 from Source
Coilovers BC Racing 90-05 Mazda Miata / MX-5 (NA / NB) coilovers BC Racing vehicle page; price is the lowest listed option. $1,215 from Source
Coilovers Ohlins Ohlins 90-05 Miata (NA/NB) Road & Track Coilover System Ohlins Road & Track coilover set, sold by Techno Toy Tuning. $2,700 Source