This article first appeared in the June, 2020 edition of SportsCar Magazine. Everyone can read the current and past editions of SportCar digitally here. To become an SCCA member and get SportsCar mailed to your home address monthly in addition to the digital editions, click here.

Mazda’s Spec MX-5 package for the NC Miata should make for economical fun in SCCA Road Racing’s Super Touring Lite – so I built one to find out

In January 2001, I traveled to Willow Springs International Raceway in Rosamond, Calif., to photograph a new class of racecar for SportsCar. This was the first Spec Miata I had seen, a lovely little white NA prepared by Larry Oka Motorsports. The class was just beginning to take off, and while it was quickly gathering momentum, few might have predicted that it would become one of the most popular classes in SCCA Road Racing and beyond, even spawning a pro series and spring boarding many drivers to professional racing careers.

Nineteen years later I was registered for the first Spec MX-5 Challenge race with the new specification for third-generation, NC-model MX-5s, to be held, coincidentally, at Willow Springs. Alas, that race was postponed due to COVID-19 and social distancing but, fortunately, I had already shaken the car down at a couple of SCCA U.S. Majors Tour race weekends and gotten a pretty good handle on how the package works.

Why Spec MX-5?

The first thing to know about Spec MX-5 is that Mazda Motorsports says it’s not intended to replace Spec Miata. As Mazda Motorsports Specialist for Technical Development, Josh Smith, who was responsible for coming up with and testing, in conjunction with Panic Motorsports, the specs for the car, notes: “We have no incentive and no reason to take from one pool and add it to another. We’re trying to grow the number of Mazda racers, not just cannibalize our own.”

In my case, I’m moving from one class to another with the same car. My own personal reason for switching my car to the Spec MX-5 configuration was competition. A little background: My 2006 MX-5 started out as part of the Mazda press fleet when the NC was originally launched, with the previous owner purchasing it from Mazda and converting it into an MX-5 Cup car when that series was sanctioned by SCCA Pro Racing. Having raced and enjoyed SportsCar’s Showroom Stock B project MX-5 in 2006, I jumped when offered the opportunity to buy the MX-5 Cup car. I raced the car first in STL for a year, then converted it to Touring 4 because I thought I would be more competitive there.

I raced the car in T4 for three years. But, in that time, in Southern California we went from about nine T4 cars in a Majors race to one – me. So, it was time to consider my options.

Dany Steyn has proven an NC MX-5 can win SCCA National Championship titles in STL, but the idea of spending the time and money he has put in to develop a winning machine from the ground up was daunting. The Spec MX-5 configuration in STL, meanwhile, offered a much more cost-effective way to have a reasonably competitive STL car, even if it’s not going to challenge the likes of Steyn for the Runoffs podium. But then there’s David Daughtery to consider.

Daughtery, a 10-time SCCA Runoffs champion, does have realistic National Championship expectations, and he’s building his own Spec MX-5, and he fully expects the car to run at the front. “I think it will be a fun class – it’s got a little more power [than Spec Miata] and the engines should be pretty darn even,” he explains. “I was one of the first people to go to the NB Miata, and I absolutely loved it; it was like an extension of your body. I loved driving them and racing them. I was on the forefront of the Spec Miata pro stuff with Jim Daniels. My biggest gripe about them was they weren’t very equal...I believe will all but eliminate that concern.”

The package is also attractive on the Regional side, with SCCA racer Todd Launchbaugh being a prime example. Launchbaugh sold his recently refreshed SM and had a Spec MX-5s built by Winding Road Racing in Austin, Texas. Winding Road has been at the forefront of Spec MX-5 and created, with Todd Lamb and Atlanta Speedwerks, the Spec MX-5 Challenge Series. That series began with refurbished Skip Barber NC Miata school cars, and is now evolving into the new spec.

“It’s not going to be much more costly and we’re going to get more power,” says Launchbaugh of his jump from SM to Spec MX-5. “It’s a small jump in cost to build for a big jump in horsepower and a more modern car.”

The Specs

“We created a racecar based on four pillars – affordability, tech-ability, reliability, and really fun to drive,” explains Mazda Motorsports Manager of Business Development David Cook. “But the car and spec components are only a portion. The right support program for the racers and for the shops, to get everyone behind this working in the same direction, is key.”

Cook’s statement reflects one big difference in Spec MX-5 vs. Spec Miata: SM was developed by racers using readily available parts. Spec MX-5, meanwhile, was developed in conjunction with Mazda Motorsports and its partners.

Much of the Spec MX-5 components are based on the old NC MX-5 Cup platform. That series raced with the cars (along with a second class for the similar, but slightly different, Skip Barber cars) for 10 years until it was replaced with the single-supplier, ND-based Global Mazda MX-5 Cup car. That means there are a lot of existing cars out there – some of them have found homes in STL or T4, but others have been sitting idle. The springs, swaybars, cold air intake, header, and exhaust for Spec MX-5 are carryovers from MX-5 Cup. “ worked really well on the car,” says Smith. “The biggest thing we’ve done is put a proper shock package tailored to the spring rates under the car.”

For that, Mazda Motorsports turned to its new partner for SM shocks, Penske Racing Shocks, which then developed a single-adjustable, tamper-proof shock for Spec MX-5. On the drivetrain side, Mazda Motorsports specs a Roush-developed cylinder head and Mahle forged pistons and a new fuel rail. Power is delivered to the wheels through an ACT clutch (OEM is allowed), and there’s a new CR Racing radiator and oil cooler to keep the engine temperatures under control, especially in a draft. Pagid brake pads, a new competition wheel from Rays (or OEM), and Toyo RR tires complete the package. Most of those components were chosen for durability, reliability and, especially in the case of the cylinder heads, they’re easy to tech.

“We went through some of our old surveys, and we had quite a few inquiries from customers if Mazda would ever make a Spec Miata cylinder head or would do a CNC cylinder head; that kind of led us down that path,” explains Smith. “We are [also] trying to build some durability into the cars. We’ve now been racing [the NC Miata] for 10-plus years, so we’ve learned a lot along the way, and we wanted to utilize all the lessons to make something enjoyable for everybody and try to reduce some of the costs in consumption rates and parts.”

The Build

Because I was converting my NC from T4 – and the optional suspension for the NC MX-5 in T4 is essentially the MX-5 Cup/Spec MX-5 suspension with non-adjustable shocks – the build was pretty straightforward. I enlisted the help of Mark Nichols at Iron Canyon Motorsports, which has taken care of the car for me and provided trackside support since I purchased it; Nichols was assisted by ONV Motorsports. Mynor Barrios had already smoothed out a few body wrinkles and applied a shiny new paint job to the car.

The suspension work was as uncomplicated as it gets, with only a little finesse and doing things in the right order required. For the engine, I had the choice of pulling mine and having it built with the Roush cylinder head and Mahle pistons; but having only one good engine, and with Mazda Motorsports offering 20-percent discounts to the first Spec MX-5 customers, getting a turnkey engine from Mazda was the sensible choice. The other engine will be converted when my bank account recovers.

With the engine out, the rest of the stuff – new clutch kit, the new radiator with an oil cooler and adapter lines – is pretty easy. Mazda Motorsports was a little light on documentation with the first ones it sent out, so there was a little bit of figuring out to do, but they promise to fix that situation. A couple items of note: There are two ports in the radiator for a zinc anode and temperature sensor that need to be plugged if you’re not using them, but the plugs are SAE and can be found at your local hardware store. Also, the correct water hose is the one for a 2006-’07 MX-5 without the factory oil cooler.

For the engine, the EGR block-offs need to be installed before the engine goes in and the manifold goes on, because at that point it’s inaccessible. Mazda Motorsports should have a kit to do that now. Also, make sure that the fuel rail is installed correctly; things can go very wrong if it’s not.

Altogether, it was about $12,000 in required parts for the conversion, including the turnkey engine. Labor, of course, depends on how much of this you’re able to accomplish yourself. And, naturally, with more parts required, the cost will be more for someone building a Spec MX-5 racecar from a street donor.

Launchbaugh bought a donor and shipped it to Winding Road. He says his build cost could have been as cheap as $36,000, but he chose some options that will take that higher, such as converting the rear hubs to RX-8 hubs, a new seat, and new data system. He estimates about $45,000 all-in. One can spend that much on a Runoffs-level Spec Miata, so it’s not a huge leap for a new build.

The Result

In reality, there are only two main differences between the NC Miata in T4 and Spec MX-5 configuration: the minimum competition weight and the shocks. The engine power isn’t greatly different (Mazda says a small power bump over a T4 engine, and that’s what the butt dyno suggests). But those other two items are the ones that make the difference.

The NC MX-5 minimum weight in Touring 4 is 2,745lbs, with 100lbs for alternate suspension and 20lbs for an aftermarket hardtop. The Spec MX-5 minimum weight, meanwhile, is 2,500lbs – and that’s also the weight for the car in STL competition if it’s prepared 100 percent to the Spec MX-5 rules, including the Toyo tires.

At the Buttonwillow Hoosier Super Tour in February, I crossed the scales at 2,593. There are some HVAC items that can be chucked, and the headlights can be replaced with blanks. And the driver needs to drop some weight as well. But the 150lb (so far) reduction over T4 trim was a huge improvement in how the car felt, especially under braking.

The Penske shocks are a huge improvement over the non-adjustable Bilsteins I had in the car, too. The adjustability is a nice touch, but simply having purpose-built racing shocks in the car feels amazing. The last complex of corners at Auto Club Speedway in Fontana, Calif., where I competed in the January U.S. Majors Tour, features a sweeping turn that is the most critical on the circuit as it leads to nearly a mile of straightaway on the oval. It’s also very bumpy. With the Penskes, the car felt far more stable through that section, and I was able to go to full throttle far sooner. For the Super Tour at Buttonwillow the following month, the shocks were then dialed stiffer.

When dialed in, a Spec MX-5 should be capable of lap times nearing those of NC MX-5 Cup times. Comparing some of those with existing track records shows that it would be competitive in STL at shorter, technical tracks, despite other cars in STL receiving aerodynamic mods and tire options.

For myself, while it’s not indicative of anything, I managed a third-place finish at the Auto Club Majors – better than any results I had in T4 in a similar-sized field – and was running third in Sunday’s Buttonwillow Super Tour when I threw it away with a mistake. In the hands of a good driver, the car has potential.

The Next Steps

For my car, the next step is to remove more weight and also install the one-inch-wider alternate Mazda Motorsports Competition MX-5 wheels, which, according to the testers, really helped the car. For Spec MX-5 in general, the next step is to see class growth, which should be pretty easy since Mazda says 50 kits to build or convert have already been sold, with Mazda prepping the next 50 kits.

Mazda’s goal for Spec MX-5, Cook explains, is for it to become its own class in the SCCA and other sanctioning bodies, but he also notes that Mazda sees that as a conversation to be had in several years. For now, however, the Spec MX-5 package in STL is an economical way to own a really fun, low-maintenance racecar. The option to race in the MX-5 Challenge Series, which races during several SCCA weekends and features pretty big prizes, only adds to the appeal. It appears Mazda Motorsports has delivered on its goals in creating the spec – now it’s up to the racers.

Words and Images by Richard S. James