One of the ways in which the driving experience between a stock Miata and a Spec Miata changes the most has to do with the shocks, springs and swaybars that a Spec Miata uses. There are probably dozens if not hundreds of aftermarket vendors that sell "upgrades" to the Miata stock suspension, but consideration of the SCCA Spec Miata rules shows that there is only one package that satisfies the requirements for the racing series:
Suspension modifications are limited to the addition of the MAZDASPEED
Motorsports Development “Spec Miata kit” and those modifications
detailed in this area.
a. MAZDASPEED Motorsports Development Spec Miata kit
1990-93 1.6 DOHC K-SPEC-M5-SUSP
1994-97 1.8 DOHC K-SPEC-M5-SUS8
1999-up 1.8 DOHC K-SPEC-M5-SUS9
The following is a breakdown of components supplied within these kits.
All parts numbers are MAZDASPEED Motorsports Development parts
numbers. No substitution of parts is allowed. The kits must be used in
their entirety.
1. Shocks
Front MAZDASPEED part #: 0000-04-5225-BL
Bilstein part # stamped on front shock: B46-1488
Rear MAZDASPEED part #: 0000-04-5226-BL
Bilstein part # stamped on rear shock: B46-1489
2. Springs
Front Eibach ERS 700 lbs/6” 0000-04-9700-06
Rear Eibach ERS 325 lbs/7” 0000-04-9325-07
3. Coil-Over kit
Front/Rear 0000-04-5402AW
4. Anti-Roll Bars
K-SPEC-M5-SUSP
Eibach kit - front / rear bars 0000-04-5302-EB
Front 24mm Adjustable
Rear 15mm Adjustable
K-SPEC-M5-SUS8
Eibach kit - front / rear bars 0000-04-5303-EBGCR - 542
Spec Miata Class Specifications
Front 27mm non-Adjustable
Rear 15mm Adjustable
K-SPEC-M5-SUSP9
Eibach kit – front / rear bars 000-04-5304-EB
Front 27mm non-Adjust
Rear 15mm Adjustable
