Enthusiasts love the Mazda Miata: it’s inexpensive, fun to drive, nimble, and reliable. Those who own a Miata understand that the performance envelope isn’t the most impressive, but that’s not the goal when you drive one of these roadsters. A welder in Rhode Island, however, decided that he wanted to have his cake and eat it too with his 1990 Mazda Miata NA, so he swapped out the engine and added turbo boost.
It’s not just any engine, by the way. Owner Ryan Hamilton installed a small-block 5.3-liter iron LM from a 2003 Chevrolet Silverado and twin Borg-Warner S300 EXC turbos. Who needs a hood when you can shoehorn in a whole bunch of power and torque?
Hamilton got the Miata two years ago when he and a friend decided to trade cars. The friend wanted the Audi wagon that Hamilton had tinkered with and switched out the engine for a 4.2-liter from an Audi C5 A6, so they made an even exchange.
The Miata was stock, lacking power windows and air conditioning, but it was very clean, Hamilton says. However, it didn’t have enough guts for him and he felt it was pretty slow.
“I figured I was going to put some kind of engine in it. It was good for autocross but I got kind of bored with the response of the throttle,” he says.
Hamilton started gathering parts; he says he did a lot of research because he didn’t know much about the LS side and figured out in his head how he could do it cheaper. No stranger to engine swaps, Hamilton’s very first vehicle was a Jeep Comanche to which he decided to add a lift kit and switched the 2.8-liter for a 4.0L six-cylinder powerplant.
“I used to do motocross until I was about 15, and then started teaching myself everything I needed to know about cars,” Hamilton told me. “I screwed up a bunch of stuff and figured it out on my own.”
The Borg-Warner turbos are on the cheaper side, he says, but they get the job done because he gets more at a lower- to mid-range; they bring the spool time down and improve the torque overall. Hamilton initially added one turbo and then tore it apart and opted to throw a second turbo on the Miata. He made the manifold himself, assembled the kit, and fit it behind the stock radiator.
The Miata has had a street tune and rough tune and Hamilton and believes it is making about 700 horsepower on 93 octane, and faster than that on race-grade 110. He’s ready for quarter-mile drag racing this season at his home track in Epping, New Hampshire with Hoosier tires and drives it sometimes around town with ETStreet Thompsons.
Before long, Hamilton wants to upgrade to a big block engine with a blower. He estimates the Mazda is nearly 90 percent modified at this point, including a 1989 Ford Thunderbird rear end. His day job is welding submarines and ships, so he knows his way around metal. Many of the parts he fabricated at his own expense with a drill press, grinder, and hand tools in his own garage. It’s clear he enjoys the process of changing it up.
“I’m just a blue-collar worker doing my own thing,” Hamilton says.
I’m looking forward to hearing about the results on the track this spring.
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