Parts Spotlight: Spec MX-5 Penske & Eibach Suspension

(Update: Penske Racing Shocks User Manuals – for front, click here; for rear, click here.)

If a Mazda’s leading characteristic is its handling, then the expectations on Mazda Motorsports for the Spec MX-5 kit was to make it even better. Working with Penske Racing Shocks and Eibach, both clear leaders in the suspension industry, the Spec MX-5 handles like no other.

Like every other aspect of the Spec MX-5, the suspension components came down to four pillars: affordability, reliability, tech-ability and really fun to drive. Through hard work testing and working closely with Penske and Eibach, those goals were reached.

The first step in the suspension program was to decide on the shock absorber adjustability. After internal discussion, Mazda Motorsports elected to use single-adjustable shocks for the Spec MX-5 program. The single-adjustable shocks give racers and teams options for set-up, without the need for a shock expert or engineer that is recommended for double-adjustable shocks. It also gives those working to move up to the professional ranks with experience in making shock adjustments, without being overwhelming. It’s possible to experiment with the eight settings of the single adjustable shock on a test day or during other sessions without dialing the car out of a competitive range.

With that issue solved, it was time to work with Penske and Eibach to build the system that makes the Spec MX-5 fun to drive.

The Spec MX-5 suspension uses 700 lb/in linear springs on the front, and 400 lb/in linear springs on the rear. All four corners utilize a 12 lb/in helper spring to prevent the main spring from becoming loose in the spring seat when the suspension is unloaded.

Up front, the suspension uses the OEM strut tower brace standard from the factory for cars with the 17” wheel option. The package utilizes the offset lower control arm bushings already offered by Mazda Motorsports to get the desired camber in the car.

The testing and work done to develop this package has led Penske to develop an aluminum isolator sleeve for the helper spring, eliminating a challenge that others have faced when trying to improve the handling of the NC generation (2006-2015) MX-5. The rear of the chassis has been hard on spring hardware in the past because of misalignment in the aftermarket shock between the linear and helper spring. Penske’s sleeve eliminates that issue.

To cap the suspension package, the car uses Eibach sway bars in the front and rear. The bundle employs a fixed front bar with an adjustable rear.

With hours of testing from Mazda’s professional racers, Andrew Carbonell and Tom Long included, the Spec MX-5 has plenty of options for those looking to ring the last hundredth of a second out of a lap time while remaining forgiving for those just entering the sport.

  • Penske front shock – single-adjustable (one of two) – spec:  0000-04-5291-SA     $549.00
  • Penske rear shock – single adjustable (one of two) – spec:  0000-04-5292-SA     $549.00
  • Penske rear mount kit (both) – spec:  0000-04-5358     $387.00
  • Front mount kit (both) – spec:  0000-04-5359     $444.00
  • Front offset bushing – spec:  0000-04-5407-NC     $75.00
  • Eibach front springs (one of two) – spec:  0000-04-9700-08     $59.00
  • Eibach rear springs (one of two) – spec:  0000-04-9400-07     $59.00
  • Eibach helper springs (one of four) – spec:  0000-04-9926     $38.00
  • Eibach front and rear sway bar – spec: 0000-04-5306-EB     $318.00


  • Sway bar end links (1 of 4) 0000-04-5597-KT   $55.00ea
  • Rays 17 X 8 +48mm offset forged wheel  $339ea

    • 0000-04-5706-GM (Gunmetal):
    • 0000-04-5706-SL (Silver)

Note: Penske Racing Shocks has made non-adjustable shocks; sold exclusively by Mazda Motorsports:
Mazda Motorsports’ Part Number – Front (one of two): 0000-05-5291-NA     $489.00
Mazda Motorsports’ Part Number – Rear (one of two): 0000-05-5292-NA     $489.00

About Spec MX-5: Mazda Motorsports has combined decades of key learnings supplied by thousands of racers at every level of grassroots and pro racing to create Spec MX-5. We’ve applied these key learnings into four key pillars: affordability, reliability, tech-ability, and really fun to drive. We’ve considered every facet of Spec MX-5 – from the car spec, the suppliers and partners, the rule set, the schedules and tracks, the ease of maintenance and repair, fun and fair competition, prizes and awards, and more. Building on the abundance of already fun third generation NC (2006-2015) MX-5s, Mazda Motorsports has developed a race kit with nearly every necessary part to convert the road car into the Spec MX-5 race car, intended for everyone from novices looking to make a long-term stay in club racing, to those aspiring to ascend the Mazda Road to 24 ladder. The focus of the support program is to enable excellent sprint and endurance club racing competition through transparency, parity, rewarding racers with the best contingency awards in club racing, the best parts pricing, and assistance from Mazda Motorsports’ experts on everything from assembly, to set up, and driving. Spec MX-5 is club racing done right. Parts for the Spec MX-5 kit begin shipping in October, so call Mazda Motorsports at 800.435.2508 now to be first in line!

Related Content: