1990 Mazda Miata Turbo - The Funky "Minimonster"

The funky purple Miata that's plastered on these pages is owned by Ric Stephens. Remember his name now, since you will be hearing a lot of it in the future. We first spotted Stephens (obviously hard to miss with a purple Miata), at the Lone Star Nationals, competing in the Street Class. As he pulled up to the line, we thought nothing much of the Mazda other than thinking to ourselves "this must be a joke, right?" A Miata trying to compete in a class dominated by Supra twin-turbos and RX-7 twin-turbos, no-way? Well, the Miata sure showed us. As the lights flashed green, the roadster left with a fury, squatting hard off the line and laying down two dark strips of molten rubber on the asphalt. Our jaws dropped in amazement as the clock down the 1320 clicked on, 11.48 at 122 mph. Stephens would later better that time with a 10.98 at 125.59 mph during exhibition rounds. We later caught up with Stephens for a Q&A session and, of course, a date with the camera.

As Stephens popped the hood of the Miata, we were expecting to see a rotary powerplant under the bonnet. But to our surprise, the Minimonster was still powered the factory four-cylinder Miata engine. Stephens told us the engine was completely stock with the exception of some mild port and polish work performed by No Limit Motorsports. Other than that, the engine is a bone-stock 1.8-liter engine found in 1994-up Miatas. We asked, bone-stock? He answered with authority, "that's right bone-stock." He also added that the block has never been apart, stock rods, stock pistons, stock crank, stock cams, stock valves, stock springs, stock everything... and the power of a turbo.

As the conversation continued, we found out Stephens was no stranger to import performance. He has owned three second-gen RX-7s (two turbo and one non-turbo), an '84 626 turbo, '88 MX-6 turbo and '88 Mazda 323 GTX. He originally started, like many of us, competing at the street races with his '88 MX-6 turbo, which did very well, he added. He would soon have the urge to go faster, seeing the limitation of the front-drive MX-6 and seeking a more professional image, he sat down with his prime fabricator at the time Corky Bell to discuss a game plan. In order to pursue his racing interests, he would have to sell his most prized possession, the MX-6 to his good friend in order to come up with the money needed to build a race vehicle. Two weeks later, Stephens would purchase a 1990 Mazda Miata for $3,000 (don't ask us, we still can't figure out why a Miata for a racecar). With the keys to his newly acquired Miata in hand, Stephens headed to Corky Bell's office to put their gameplan in motion. The two brainstormed and came to the conclusion that the factory 1.6-liter engine would have to be replaced with the larger 1.8-liter displacement Miata engine. Stephens combed the local junkyards and found a complete 1.8-liter engine for $750. Wasting no time at all, the 1.6-liter engine was yanked out and the new 1.8-liter found its way into the engine bay.

After the engine was installed, a custom Corky Bell turbo kit was fabricated for the Miata. The turbo kit is a one-off custom kit that Stephens designed himself using custom parts. The cast turbo manifold is a Corky Bell unit, which has been reworked by Stephens to achieve better flow characteristics. Mounted to the manifold is a custom turbocharger.com T4/T3 hybrid hairdryer capable of producing more than 25 psi of atmospheric pressure. An HKS EVC IV boost controller and Corky Bell wastegate handle boost control duties. From the turbo, spent gases are expelled from the turbo housing via a custom Thunder Fabrication 3-inch downpipe exiting through a 3-inch Ultra Flow canister. On the compressor side, boost pressure is routed through 2 1/2-inch mild-steel I/C piping to a custom Corky Bell front-mount intercooler. After ample chilling, the charge air is then force fed into the port-matched intake manifold.