# Mazda Spec Miata (NA and NB, 1999–present)

- Source: https://racingcarnetwork.com/wiki/mazda-spec-miata/
- Publisher: Racing Car Network (racingcarnetwork.com), the race car marketplace
- Type: car · Brand: Mazda
- Discipline: touring
- Series: one-make-cup
- Era: 1990s
- Last updated: 2026-11-06

Spec Miata is the American club-racing class for first and second generation Mazda MX-5 Miatas built from 1990 to 2005. SCCA and NASA both run it with near-identical rules, weights and restrictors. Cheap parts, huge grids and a busy used market make it the default entry car for new road racers in the US.

## Specifications

| Spec | Value |
|---|---|
| Engine | Mazda 1.6 DOHC I4 (1990-93) or 1.8 DOHC I4 (1994-2005), internals locked to OEM parts and factory dimensions [0] |
| Power | Factory: 115 bhp (1.6), 129-133 bhp (1994-97), 140 bhp (1999-00), 143 bhp US (2001-05) [13][14]; one 2012 SM engine dynoed 123 rwhp [10] |
| Weight | Minimum with driver: 2,275 lb (90-93), 2,385 lb (94-97), 2,400 lb (99-00), 2,450 lb (01-05); +15 lb with overbore [0][1] |
| Restrictor | None on 1.6 and 1994-97 cars; 38 mm plate on 1999-00; 40 mm plate on 2001-05 [0][1] |
| Gearbox | Stock Mazda 5-speed (3.14, 1.89, 1.33, 1.00, 0.81), 4.30 final drive, OEM open or limited-slip differential [0] |
| Suspension | Mazda Motorsports Spec Miata kit, Eibach 700/325 lb springs, Bilstein (regional) or Penske SM shocks [0][1] |
| Brakes | Front 235 mm vented / rear 232 mm solid (1.6); front 255 mm vented / rear 252 mm solid (1.8) [0] |
| Tyres | 15 x 7 in wheels; Hoosier 205/50ZR15 SM7.5 or RCES dry, SMW wet (SCCA); Hoosier RCES (NASA) [0][1] |
| Years | Class from 1999; eligible cars 1990-1997 NA and 1999-2005 NB [0][2] |
| Class | SCCA Spec Miata (SM), NASA Spec Miata [0][1] |

## History

Spec Miata began as a regional class in the SCCA Southwest Division in 1999. The first race ran on 24 July 1999 at Texas World Speedway, with four starters [2]. NASA's NorCal Region followed with its own first race in February 2000 [2]. The SCCA describes the class as more open than Showroom Stock but tighter than Improved Touring [0].

The SCCA granted national status for 2006. The first national race took place at Phoenix on 13 January 2006, and Brad Rampelberg won it [2]. Andrew Caddell became the first Runoffs champion that same year [2]. NASA has crowned a national champion almost every year since 2006 [2].

The class mixes three engines and two chassis, so parity comes from minimum weight and intake restrictors. The 1.6 cars run without a plate at 2,275 lb, while the 2001-05 VVT cars carry a 40 mm plate at 2,450 lb [0]. The SCCA restrictor table still lists past sizes of 41, 43 and 45 mm, a record of repeated rebalancing [0]. In 2026 the SCCA and NASA tables show the same weights and plates [0][1]. Engines must use Mazda OEM internals, with a 0.010 in overbore allowed for a 15 lb penalty [0]. Shocks come from Bilstein or Penske through Mazda's kit, and Penskes are now compulsory at SCCA Majors and the Runoffs [0].

Later Miatas are handled elsewhere. The SCCA runs the 2006-2015 NC car in a separate Spec MX-5 class [0], which Mazda announced in 2019 [2]. The Global MX-5 Cup is a professional series with its own card. Vintage clubs also take the cars: SVRA runs them in Group 3 and defers to the SCCA rulebook [12].

## Palmarès

Spec Miata is an amateur class, so its record is club titles. SCCA Runoffs champions include Andrew Caddell (2006), Brad Rampelberg (2007), Jim Drago (2012 and 2013) and Preston Pardus (2017, 2020, 2021) [2]. The 2023 Runoffs ended with co-champions Nick Bruni and Preston Pardus, and Ethan Goulart won in 2024 [2]. In NASA, Todd Lamb won in 2007 and 2008 and Lincoln Larson took the 2025 title [2].

## What to check before you buy

Match the firewall VIN to the model year being sold: Both SCCA and NASA classify the car by the firewall VIN, and it decides weight and restrictor. Inspect the SCCA logbook: issue date, cage description, photos and ownership changes: Only one logbook may exist per car and holding two is a rules breach. A current logbook is still not a guarantee of condition. Check the cage mounts and fit for your height: SM cages may attach only at the six required points, with at most two gussets per joint up to 0.125 in thick. Poor fit is common on older cages. Ask who built the engine, its hours, a dyno sheet and whether it is overbored: An overbored engine adds 15 lb to the minimum weight, and engine freshness drives both pace and resale value. Confirm the restrictor plate size, colour and origin on NB cars: Plates must be the listed size from Mazda Motorsports or SCCA Enterprises and unmodified: purple 38 mm on 1999-00, silver or multicolour 40 mm on 2001-05. Identify the differential type and ratio, and look at the housing ears: Only listed diffs with the 4.30 ratio are legal in SCCA, and unbraced ears can snap after contact. Inspect the front subframe welds at the lower control arm mounts: Owners report cracks at this weld, sometimes ending races. Note whether the car has Penske or Bilstein shocks: Penskes are required for SCCA Majors and Runoffs and for NASA Championships.

## Did you know

- The first Spec Miata race, on 24 July 1999 at Texas World Speedway, had just four starters [2].
- SCCA restrictor plates are colour-coded: purple for 38 mm and silver or multicolour for 40 mm [0].
- The 2023 SCCA Runoffs produced the event's first co-champions, Nick Bruni and Preston Pardus in Spec Miata [2].

## Frequently asked questions

**Should I buy a 1.6, a 1.8 NA or an NB?** All three are legal and balanced by weight and restrictors. Most expensive top builds are NB cars, while older NA cars stay competitive locally and cost less. The 1.6 has the lowest minimum weight at 2,275 lb with driver, which heavier drivers may struggle to reach.

**What is different between SCCA and NASA Spec Miata?** In 2026 weights and restrictors match. SCCA specifies Hoosier SM7.5 or RCES tyres; NASA uses Hoosier RCES and allowed Toyo RR early in the season. NASA lets 1994-97 cars keep the 4.10 diff regionally and permits non-OEM rear hubs. Check both rulebooks before buying.

**Do I need Penske shocks?** Not for regional racing. SCCA requires the Penske SM shock and mount at Majors and the Runoffs, and NASA requires Penskes at Championship events. Bilstein cars remain legal at regional level. The upgrade cost about US$1,200 over Bilsteins in 2020.

**What does a season cost?** One NASA regional champion reported about US$6,700 for six weekends in 2023, with entry fees the largest item. He used contingency tyres and pads and a cheap used engine. Front-runners buying fresh tyres and engines spend far more.

**Is this the same as the Global MX-5 Cup?** No. Spec Miata is an amateur club class for 1990-2005 NA and NB cars run by SCCA and NASA. The MX-5 Cup is a professional series for current cars. The SCCA also runs the 2006-2015 NC car separately as Spec MX-5.

**What paperwork should come with the car?** Ask for the SCCA or NASA logbook, which records the cage, photos and ownership changes. SCCA also requires a Mazda factory shop manual for the car's year in the entrant's possession. Engine build sheets and dyno results support the asking price.

## Sources

- 2026 General Competition Rules, November 2026 edition, section 9.1.7 Spec Miata — https://www.scca.com/wp-content/uploads/2026/11/NOV-26.pdf
- Spec Miata Official 2026 National Rules, Version 1.3 — https://members.drivenasa.com/rules/spec_miata_rules.pdf
- Spec Miata — https://en.wikipedia.org/wiki/Spec_Miata
- How much does a Spec Miata cost? A buyer's guide for club racing's most popular class — https://nomoneymotorsports.com/2020/11/02/how-much-does-a-spec-miata-cost-a-buyers-guide-for-club-racings-most-popular-class
- How much does a season of racing Spec Miata cost? — https://nomoneymotorsports.com/2024/06/25/how-much-does-a-season-of-racing-spec-miata-cost-it-can-be-done-for-less-than-youve-heard/
- Bracing a Miata differential — https://nasaspeed.news/tech/drivetrain/bracing-a-miata-differential/
- Miata front subframe reinforcement (forum thread) — https://forums.comscc.org/viewtopic.php?p=45660
- Crank keyway and timing gear damage / repair (forum thread) — https://bbs.zuwharrie.com/threads/crank-keyway-and-timing-gear-damage-repair.15988/
- 2005 Mazda Spec Miata - fresh X-Factor build — https://race-cars.com/Advert/Details/132536/2005-mazda-spec-miata---fresh-x-factor-build
- 1990 Spec Miata for sale (forum thread) — https://icscc.com/forums/threads/1990-spec-miata-for-sale.2143
- FS: excellent, tested Race Engineering Spec Miata motor (forum thread) — https://icscc.com/forums/threads/fs-excellent-tested-race-engineering-spec-miata-motor.2397
- Spec Miata Racing Engines — https://rossiniracing.com/?p=22
- SVRA Supplemental Regulations: Mazda MX-5 Miata, Group 3 — https://www.svra.com/wp-content/uploads/2025/01/spec-miata.pdf
- Mazda MX-5 (NA) — https://en.wikipedia.org/wiki/Mazda_MX-5_(NA)
- Mazda MX-5 (NB) — https://en.wikipedia.org/wiki/Mazda_MX-5_(NB)
- racingcarnetwork.com search: spec miata — https://racingcarnetwork.com/?s=spec+miata

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