SCCA Spec Miata
With the cockpit and driver safety systems of the SCCA Spec Miata racecar build squared away, it was time to focus on what, in large part, makes a Spec Miata a spec: suspension.
The required Spec Miata suspension kit includes a set of spec Bilstein shock absorbers, Eibach springs and sway bars, and adjustable coilover sleeves. Having the suspension come as a kit removes a lot of guesswork when building the car, and helps keep the competition tight. And while optional, a few must-have suspension upgrades are available, namely the Fat Cat bump stop kit, a set of adjustable swaybar end links, and offset control arm bushings. You can race a Spec Miata without these parts, but most everyone in the Spec Miata community agrees these are worthwhile additions.
The installation of the basic suspension kit can be performed in your driveway with simple hand tools. "The most difficult part of the installation was removing the 15-year-old nuts and bolts that were cemented on there, " Jennifer Isley, multi-time SCCA Solo National Champion, points out of the 1999 Miata she's building to take to the 2017 SCCA National Championship Runoffs at Indianapolis Motor Speedway. "Once I figured out how everything went together, the installation went smoothly."
If you opt for the offset control arm bushings, it helps to have access to a press for removing the OE bushings and installing the Delrin units. For this installation, Isley elected to install the offset bushings in a fresh set of OE upper control arms, discarding the old set that had covered nearly 100, 000 road miles.
With the car still in the air, the brakes were next on the list. Isley jettisoned the factory dust shields for improved cooling, added a set of stainless steel brake lines, and installed a set of race-grade brake pads. Hawk Performance DTC-60 pads up front, and DTC-30 in the rear would take care of the stopping.
When it comes to rolling stock, Spec Miatas sit on the spec Hoosier SM7 tires for dry races and the Hoosier H2O tire in the rain, both sized in a 205/50-15. The SM7 has proven to be a durable tire that performs well over a great number of heat cycles, making it both a good value and good for competition.
Wheels allow some flexibility as long as they meet the size and weight specifications laid out in the rules. You want to pick something that is durable, offers good cooling for the brakes and is right around the minimum weight. "Ever since I got my first car, Momo wheels were always my favorite, " says Isley. "When I found out they had a wheel built specifically for Spec Miata, I had to have them."
The Momo Podium wheels check all the boxes for a Spec Miata, plus they're reasonably priced.
Finally, a set of ARP wheel studs would secure the wheels safely in place, while MiataCage.com wheel spacers allow for fine-tuning of track width.
Preparing for the Hoosier tires to touch the garage floor for the first time, a baseline alignment was needed – this is where a visit to pays off. Mazda offers racers comprehensive alignment instructions and specifications – but be prepared, this is repetitive work. "Adjusting the ride height and aligning the car was tedious and time consuming with lots of going back to make changes, " Isley notes.