A difference in size and power are what strike most observers when first comparing the third-generation (NC) Miata to its predecessors (NA and NB). However, it would be unfair to think of the NC and the Spec MX-5, the racing version garnering this generation nationwide appeal, as simply porkier, punchier versions of their predecessors.
With the aid of two of Spec MX-5 Challenge’s rising talents, two drivers who cut their teeth in karts and Spec Miatas, we’ve learned exactly how the Spec MX-5 differs from the Spec Miata in terms of driving. Not only must the power bump be considered when trying to squeeze a quick lap from the Spec MX-5, but its greater level of refinement changes the driving approach, too. While the cars aren’t hugely dissimilar, their distinctions encourage a clever driver to prioritize different parts of the corner, exercise more caution in certain situations, and treat the inputs differently.
The Spec MX-5 brought a few assets into the ring to counteract its extra heft. At 2,500 pounds, it’s about 200 pounds heavier than your typical NA or NB-generation Spec Miatas, but its 2.0-liter MZR motor changes the rate at which the scenery passes by. Thanks to recent revamp with a Roush cylinder head, Kooks headers, Mahle pistons, and a C&R cooling system, the MZR makes around 170 horsepower and 150 pound-feet of torque at the rear wheels.
Predictably, the bigger car is faster, but the difference may catch some by surprise because the numbers don’t completely convey the difference in straight-line performance. In fact, the first iteration of the Spec MX-5 car is about 5 seconds faster than a Spec Miata — a Spec Miata on slicks, no less — at fast tracks like COTA and Road America. Put the two cars together on a track and within two corners, it becomes clear that the Spec MX-5’s greater acceleration isn’t just a minor improvement—and that is only one of the ways in which the newer car differs.
A Softer Front
Wyatt Couch chimed in with his take on the car. With a couple wins in the Spec MX-5 Challenge’s West Coast division and several successful seasons in Spec Miata, he’s in a position to make an informed statement about the differences between the two.
“The Spec MX-5’s power steering makes it a lot easier to get it to turn in,” Wyatt added. This holds true even after a race weekend with an understeering car. The wider tires up front — 235s compared to 205s — also contribute to this sharp turn-in.
However, the Spec MX-5’s softer, power-assisted steering doesn’t convey quite the level of detail its analog predecessor does. Couch isn’t completely sure with the new car’s system. “I prefer the feeling of the Spec Miata as I feel more through the wheel. The Spec MX-5 isn’t completely disconnected, but you lose a little bit of that feedback.”
Sawing at the Wheel
Despite all this softness in the steering, the Spec MX-5 is even busier as far as counter-steering is concerned. Due to the way the car is sprung and the tire compound, it’s definitely a wild ride that rewards those comfortable sliding the rear around.
The truth according to those who’ve made the transition to the bigger car is mixed. The Spec MX-5, according to most who know both cars, feel floatier. Connor Zilisch, a front runner in Spec MX-5 and Spec Miata, agrees here: “It feels like the rebound time is slower. It takes a little longer to take a set. It’s also a little ‘freer,’ which means you usually have to drive with more oversteer.”
Perhaps it feels like it sits on top of the pavement more than a Spec Miata, but it’s still benign and ultimately quite playful — maybe more than the Spec Miata.
That’s why Couch learned quickly that, in order to get the lap time from the newer car, he couldn’t throw it around and drive off the corner while counter-steering. He had to be smoother to keep the car underneath him.
Even if that bump in power seems insignificant on paper, it seriously alters the way the throttle should be applied. “You use throttle in the Spec MX-5 more carefully. There’s enough torque to get the back end out of shape in the slow stuff. Even in the faster corners, the throttle can change the balance of the car,” says Zilisch.
The extra torque and tendency to “sit on top of the road” means breakaway is a little more abrupt in the Spec MX-5, but that doesn’t mean that slides aren’t easily caught. It’s just that the Spec MX-5 needs to be driven more smoothly since regularly oversteering in this fashion has more of a detrimental effect on lap times. In the Spec Miata, the power level is lower and the slides are typically less severe, so oversteering doesn’t slow it down quite as much.
To find the respectable lap time with the punchier Spec MX-5, it takes a slight readjustment in prioritizing the different cornering phases. “You really need to focus on the mid-corner speed and try to be clean at the exit,” Couch instructs.
With the older car, charging through the exit of the corner with the right foot flat is usually fine. A little counter-steering at corner exit won’t make much difference. “Besides, the Spec Miata’s throttle works like an on-off switch,” Couch laughs.
The 200 additional pounds should be noticed here, but they aren’t. Because the Spec MX-5’s outright braking force is greater than the Spec Miata’s, and because the ABS makes the task of braking a little easier, the braking distances are consistently shorter. Additionally, people can rely on the Spec MX-5’s ABS a bit. “I lean on the ABS 100%—unless it’s raining.”
“When braking in the Spec Miata, there is definitely a lot more modulation involved since there is no ABS. It forces you to hold threshold pressure without locking up, unlike the Spec MX-5, which you can just put the brake pedal to the floor with, provided it’s dry,” Zilisch says.
The newer car is, at the end of the day, still a Miata. An accurate, forgiving machine that serves to establish a strong foundation for any aspiring racer. It’s just that the newer car is, well, newer. More powerful, softer, happier to oversteer with the rightmost pedal, cushier, and no less challenging. It shouldn’t be seen as some unfortunate dilution of a pure racer. It’s still a supremely sharp car—and one with a different enough character to challenge and entertain a Spec Miata racer looking to change things up.
Coming from a Spec E30, the Spec-MX5 feels like a slot car.