10.9 @ 122 mph
532 whp @ 22 psi
Mazda blazed a trail through the American automotive landscape on the wings of the rotary engine. From the R100 through RX3 to the venerable RX-7, Mazda's performance flagships have always been powered by a Wankel rotary engine.
Today, production of the rotary in new cars is in exile, but rumors of its return in 2004 or 2005 persist. However, the performance industry hasn't missed a beat since the untimely demise of the RX-7. In fact, things have gotten better as the cost of used 7s has dropped considerably to where the once-$40,000 car can be had for under $10,000. This opens the floodgates, as owners are more inclined to modify their FDs. The 13B rotary is a small engine, and we're not talking about its 1.3-liter displacement. Its dimensions are small, which means it can fit in a variety of vehicles. We have seen rotaries in Toyota Starlets, Datsun 1200s, Chevy Blazers, Suzuki Samurai and even motorcycles. However, the most fitting swap has to be the Miata, making it an all-Mazda affair.
The 13B-REW fits easily in...
The 13B-REW fits easily in the Miata's engine bay. Rampage Racing's impressive handiwork made the swap appear OE. Engine management duties are conducted by a Haltech E6K system. The rotary powerplant, scavenged from a 1995 RX-7, was street ported and converted to single-turbo duty. Rampage fabricated a single-turbo manifold from stainless steel to locate a HKS T04S turbo.
A rotary-powered Mazda Miata has a lot going for it, high horsepower potential, light weight, rear drive, etc. Ginny Abdul of Queens Village, New York bought his 1990 edition used and knew right away that he needed more power. He purchased a GReddy turbo kit and contacted Rampage Racing in Woodside, New York. "At first it felt fast," said Abdul. "But I soon outgrew the power. I had seen where Racing Beat had a rotary swap kit and called Rampage. [The staff] did some research for me and recommended the 13B-REW engine and Haltech engine management, because a swap using the stock harness system would not have worked. We also decided to go single turbo and set out the specs of the fuel system."
The 13B was street ported and Rampage fabricated a trick, stainless-steel tubular exhaust manifold to position the turbo. The roadster is boosted by a HKS T04S wrangled to a maximum boost of 22 psi by a Turbonetics Racegate and a GReddy PRofec A boost controller. With its huge front-mount intercooler, the Mazda's pressurized personality is readily apparent. The air-to-air chiller feeds boost to a hand-ported intake manifold through polished tubing and a stock RX-7 throttle body. Once combustion is complete, a custom 3-inch downpipe and exhaust system with an A'PEXi muffler dispenses spent gases.
The Mazda's brain power comes from a Haltech E6K, which features ignition timing control, fuel control, idle speed control and closed loop operation. The system can be configured for datalogging, which allows access in real time to troubleshoot problems in a vehicle while the engine is running.
The hand-ported intake manifold...
The hand-ported intake manifold and all pertinent tubing was polished to show standards. An HKS Super Sequential blow off valve is on-call to resist compressor surge.
The fuel system relies on...
The fuel system relies on two primary injectors and two secondary injectors to fulfill its commitment to fuel enrichment. The rest of the set-up consists of an SX fuel pump, -8 lines, SX regulator and custom Rampage fuel rail.
As far as programming is concerned, all adjustments are made by manipulating bar graphs and pressing arrow keys to increase or decrease the amount of fuel delivered at that particular load point. The process is repeated for all load points in each rpm range. The 13B runs two primary injectors and two secondary injectors to fulfill its fuel enrichment commitment. An SX fuel pump, -8 lines, SX regulator and custom Rampage fuel rail round out the system. With fuel and air in the combustion chamber the only remaining ingredient is spark. The 13B relies on an MSD 6A box, Magnecor 10 mm wires and GReddy plugs to light the fire.
Since the engine is so light, the Miata retains its balanced handling characteristics. The suspension is enhanced by means of a set of Tein coil-overs, which drop the car's center of gravity by 2.5-inches in front and 2.6-inches out back. The fun factor when slicing through canyons is increased with the addition of Racing Beat sway bars and Baer Racing upgraded brakes.
In addition to the RX-7 engine, the Miata sports an accompanying RX-7 transmission and rear-end. To make the driveline work, Rampage used an RX-7 rear subframe, custom billet aluminum tranny mounts and a custom aluminum driveshaft. An ACT six-puck clutch helps put the power down to the road.
The Miata flexes a Racing Beat body kit and roll bar, but plans call for the addition of an NHRA-spec set-up and a 100-hp nitrous system. With these mods on line, the Mazda roller skate will shock any vehicle that crosses its path.
Since the Miata is a pure...
Since the Miata is a pure street car, the interior is relatively stock. The seats are out of a Mazda RX-7 R1. A'PEXi boost and exhaust gas temperature readouts have been placed in the A/C vents; they are a perfect fit.
The Miata runs an RX-7 engine,...
The Miata runs an RX-7 engine, gearbox, rear-end and a custom driveshaft. It's posted a 10.9-second, 122-mph quarter mile at Englishtown, even with severe wheel slip.