Which NA Miata Is Right for You?
Photograph Courtesy Mazda
In 1994, the NA Miata underwent a refresh that included a move from the original 1.6-liter engine to a 1.8-liter engine. Other upgrades included larger brakes, a larger fuel tank and a larger, stronger rear end fitted with an optional Torsen differential. The passenger side of the dash gained an air bag. The available alloys grew from 14x5.5 inches to 14x6.
“The first thing you want to do is decide if you want the 1.6 or the 1.8,” Keith says. “The 1.8 is definitely the performance option. Plus, it’s got more parts in common with the later cars.”
Some, such as Keith, still prefer the 1.6-liter for its interior and also the engine. “The 1.6 has a different character to it,” says Keith. “It’s a revvier engine–it wants to be spun past 4000 rpm. When you drive a 1.6 and a 1.8 back to back, the 1.6 has a sportier feel, but it doesn’t make as much power or low-end torque, so it is slower.”
For those seeking even more power, Miata got another 5-horsepower bump in 1996.
As far as trim levels, Keith suggests considering an NA Miata with the R package. It came with Bilstein shocks, manual steering and a Torsen limited-slip differential. Because it lacks power steering, they’re often less expensive unless the seller is in the know. It was only offered with the 1.8-liter cars, so 1994 and up.
“It’s more of a road race package,” Keith says. “The manual steering is a downside for autocross. It might be a cheap way to get a Torsen. I wouldn’t necessarily seek one out otherwise, because those shocks are probably toast by now. You can mix and match parts [between different NA Miata trims].”
As far as any special editions, most of the changes to those cars were merely cosmetic and nothing performance-oriented.
Things to Look Out For
Photograph Courtesy Mazda
Let’s face it, the NA Miata is an antique, and age takes the typical toll on one. However, with those years and miles also comes loads of data that can show which areas of the car to keep an eye on.
“For the first year and a half of production, from 1989 to 1990, the crankshaft nose was under-engineered,” Keith notes. “Mostly it’s not a thing to be concerned about as long as you don’t let the crank bolts loosen off. So if you’re doing a timing belt chain change, Loctite that bolt and torque it properly.”
Look out for rust, too, particularly in the sills, which can affect the car’s structure and will loosen the car’s handling.
One potential problem with the Miata might stem from the one demographic it attracted. “When they went through the valley of depreciation, they often became stanced cars or drift cars and were heavily abused by the owner,” Keith says. “A lot of them didn’t come out the other side very well.”
On the flip side, many Miatas were also owned by seasoned, caring individuals. “A lot of them were second cars,” Keith continues. “They were Sunday toys owned by older owners. There are still some cream puffs and well-attended cars.
“In terms of weak points, there’s nothing specific that really jumps out,” says Keith. “They’re really quite durable little critters.”
If you’re thinking of buying one, though, you might want to do so soon, as Keith notes that prices are climbing. Hagerty values a 1990 Miata in good condition at $9200 and a 1994 at $10,900.
What It Takes to Track an NA Miata
Photograph Courtesy Mazda
Okay, so you want an NA Miata, but not just for going on Sunday drives; you want to compete with one in some form of motorsport. No problem, especially if you’re a newbie to competition.
“It’s an excellent platform to learn on,” says Keith. “It doesn’t fight. It doesn’t have any bad behavior. The Miata flatters the driver. The Miata responds directly to what you’re doing. It gets to the point where the car becomes more or less out of the equation.”
The first step to competing with a NA Miata is confirming all the mechanicals are up to snuff. That includes items such as the brakes and shocks.
“It’s a 25-year-old car,” Keith says. “Don’t overlook the fact it has an oil leak or it stumbles over 3000 rpm.”
Due to that age, pay close attention to the cooling, too. “The radiators have plastic end tanks on them that over time become brittle,” says Keith. “The best way to tell if the radiator needs to be replaced is to look at the color of it. If it has a greenish tint, it’s probably a good idea to replace the radiator.”
Before you hit the track, the sanctioning body will most likely require you to add a roll bar. If you’re a taller driver, other work might be needed so the bar clears the helmet–like dropping the floor, installing a race seat or removing some seat foam from the original bucket.
The aftermarket is also ready to deliver all the necessary performance mods. New suspension bushings will liven up a car, says Keith. Upgrading the anti-roll bars is a good move, too.
“It’s an easy install,” Keith says of sway bars. “It livens the car up in terms of having it turn in better. It keeps the car flatter. It helps adjust the handling balance of the car. It’s the best bang for your buck.”
Then come the usual mod suspects, such as tires and wheels. A wider 205/50R15 is a good start. With some thought in wheel selection, you can go to a 225/45R15 without rolling the fenders.
Whatever you do, though, Keith says the wheels are one of the few areas where you can shed pounds in a Miata–other than installing a lighter exhaust. “Spec Miata has a minimum weight of 12.5 pounds, and there a lot of good options out there with that weight. Don’t throw a bunch of 20-pound, cheap wheels on there–it will deaden the car.”
If you have an early, 1.6-liter Miata, you can easily install the bigger brakes from an NA Miata with a 1.8. In fact, if you’re feeling exceptionally giddy, you can swap in an NB Miata’s front suspension and cradle, which has better geometry, by just bolting it in.
“You’ll get a bigger bang for your buck out of your suspension, tires and wheels, chassis, brakes than you’ll get with horsepower,” Keith notes. “To get significant amounts of horsepower, you have to spend at least $4000, and other challenges come along with it.
“The NA Miata is definitely going to be the slowest car in a straight line at a track,” Keith continues. “For some, that’s a bit worrisome at high-speed track days; you can definitely feel a bit exposed. But it’s still a good choice as far as fun, as long as you’re measuring what’s going on in your car and not in a Corvette.”
The Biggest Pro to Owning a Miata
Photography Credit: David S. Wallens
Perhaps the best part of owning a Miata is who supports it. More than 1 million Miatas have been produced. The NA Miata has a strong aftermarket, and just about any part you need for it is available, whether it’s for restoration or for performance.
Even Mazda supports the NA Miata through its Mazda Team Support Program. It gives you access to factory parts at the lowest price on the market.
If factory support and the robust aftermarket doesn’t turn you on to the Miata, fellow Miata owners will. “It’s always had a strong enthusiast connection,” says Keith of the NA Miata. “The Miata Club of America started almost immediately after the Miata was first sold.”
Photograph Courtesy Mazda
