Further Development of his ND2 Miata made it the perfect Sport 5 weapon at the SCCA Time Trials Nationals

For the second straight year, Andy Hollis returned to Texas from NCM Motorsports Park in Bowling Green, Ky., with an SCCA Tire Rack Time Trials Nationals win during the event’s sophomore year. This year, Hollis saw success in the Sport 5 class in his 2019 ND2 Miata that he has been developing throughout the year.

When MazdaMotorsports.com last checked in with Hollis, he had completed much of the suspension development work, but the front swaybar he had installed for autocross wasn’t Time Trials legal since it did not utilize the stock configuration. To that end, he worked with Good-Win Racing to obtain a Progress stock-style front swaybar. Hollis then swapped the rear swaybar with that from the Fiat Spyder, which shares the basic chassis with the ND Miata. Since then, much of his development has centered on wheels and tires.

“I went to larger wheels and tires,” Hollis explains, noting that he put on a set of 949 Racing 6UL wheels measuring 17×9 inches, and wrapped those in 245/40-17 Bridgestone RE71R tires. “That fits in the car without rolling the fenders and without any significant rubbing. It’s about the biggest thing you can put in there for 200-treadwear sticky tires. Sport 5 doesn’t allow fender rolling, so that was pretty much maximizing that situation. 

“I tried a couple of different things while trying to figure out what the right combo was,” Hollis continues. “I found that even though that setup is heavier than some of the other ones because it’s so much larger, the cornering speeds more than made up for the loss in acceleration as well as the additional rolling mass that you had to brake to slow for a turn. Looking at the data, you could see where the time was made – it was made in the turns, even though it was a bit slower in a straight line.”

Hollis references data, and it points to another improvement he made to the car: an AiM Solo DL that gathered the information. The Solo DL data also showed him that another combination he tried, a 205mm tire on a light set of 16-inch SSR rims, was almost as fast as the bigger rim-and-tire combo. The lighter set helped the car accelerate and brake better, but was slower in the middle of the turns. “It’s possible on some tracks that this setup might actually be faster,” he adds.

A Blackbird Fabworks roll bar was also added to the car, partially at wife Ann’s insistence and partly because he was going to some racetracks he didn’t know nearly as well as Harris Hill, his backyard proving ground. That roll bar fits under the factory top, which brings up another things Hollis discovered.

“I was running a Time Trials at [Circuit of the Americas] and I was able to do a little testing,” he notes. “I ran some sessions with the top up and some sessions with the top down, just to see what the aerodynamic difference would be. Leaving the top up was worth almost a full second at COTA. Looking at the data, it’s entirely where you’d expect it – from 100mph on up, the car continues to accelerate. The car looks better with the top down and you get better visibility, but you’ve got to go with what’s quicker.”

Hollis took the car to a couple of SCCA Time Trials National Tour events earlier in the year, at High Plains Raceway and Heartland Motorsports Park. In between, he and Ann went to Rocky Mountain National Park to do some hiking. He notes that the Miata, although prepared to be a winning Time Trials car, was a delight to drive down mountain roads.

“I continue to love this car,” Hollis enthuses. “The ND2 motor continues to impress, and I love the handling of the car. We would drive the car on mountain roads and really enjoy it. It’s not harsh like some of the autocross cars that people put together. It’s lowered just enough so you can get good camber, and with the swaybars, you can get the balance you want. With 200-treadwear tires, it’s a great dual-purpose car.” 

Other than the parts mentioned above, Hollis has used Koni shocks on the car, Pagid brake pads – the RS29 endurance pad in the back and RS1 in the front – and Flying Miata parts. His next event will be the One Tank Challenge at Harris Hill Raceway, an event he won previously with the ND1. The goal of that event is to run three hours on a single tank of fuel, and whoever goes the farthest in that three hours wins.

“You need a car that’s good on fuel and doesn’t have to slow too much for the turns,” he says. “It’s another completely different kind of thing that this car is perfect for.”

Mazda Winners from the 2019 SCCA Tire Rack Time Trials Nationals:
Unlimited 2: Bowie Gray, 2004 RX-8
Max 2: Perry Ellwood, 2004 RX-8
Max 3: Dallas Reed, 2004 RX-8
Tuner 5: Christopher Finnigan, 1999 Miata
Sport 5: Andy Hollis, 2019 Miata