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1993 Mazda RX-7 R1 - RX-7 Obsession

Bill Klein
Oct 12, 2005
Photographer: Henry DeKuyper
Turp_0510_z+1993_mazda_rx7+front_view Photo 1/1   |   1993 Mazda RX-7 R1 - RX-7 Obsession

High school is a time when life begins to take shape. Personality traits and obsessions become clearer. For better or worse those years can brand a person for life. Any auto enthusiast can tell you that around this time one particular brand or make of vehicle can become part of their DNA. For Chuck Duncan of North Little Rock, Ark., he found his true love his senior year-1992-in a Mazda dealership and hasn't looked back. After an all-too-brief introduction, he would spend the next eight years pining for her before she finally became his.

Back in '92, Chuck's obsession took hold of him with his first RX-7, an '85 model. The subsequent eight years and five first-gen RX-7s later his Mazda affliction was deep and incurable. Then in 2000, he came across a brilliant black 1993 Mazda RX-7 R1, just like the one he sat in back in '92. The lure of obtaining his high-school love with a deal that included a partial trade of his then current '85 RX-7 GSL-SE and cash was too tempting to pass up. The deal was struck at Six Flags Over Texas, in Arlington, Texas, over 350 miles away. The six-hour ride home must have felt like the greatest roller-coaster ride of his life, filled with excitement and touch of fear while excessive amounts of adrenaline coursed through his system.

The car was slightly modified at the time, which was OK for a while. But Chuck wanted more from their relationship, more power and more style. As it is for most of us, car modifications came when time and money allowed. Some parts have stayed but most have been upgraded or replaced as the car's buildup progressed.

The rotary engine has gone through changes since day one in search of more power. For this latest incarnation, Demented Racing was called in to assemble the engine. To start with, the twin-turbo setup was ditched in favor of a single Garrett GT35/40 turbo. For increased flow the manifold was ported, polished and internally hot-coated. While the rotor housings were out at Atkins Rotary getting a street port, they added some of their own 3mm apex seals. A TiAL 46mm wastegate and BOV keep boost pressures in check. Pressurized air passes through an A'PEXi GT intercooler before entering the GReddy intake elbow. Exhaust gasses are expelled through a modified A'PEXi Dual N1 cat back system to include dual 2.5-inch Borla XS mufflers.

Designing and fabbing up the fuel system fell to Polk Performance of Bryant, Ark. What they came up with to keep this twin-rotor properly fueled was to use Keith's Rails primary and secondary fuel rails, 756cc primary and 1680cc secondary injectors. Pushing the fuel to the injectors is a Walbro 255lph pump. Fuel pressure is regulated by an Aeromotive FPR. Firing off the mixture falls to Bosch HEC-715 coil packs, Magnacore R-100 10mm race plug wires and NGK Racing 10.5 heat range plugs.

Keeping the electrons flowing and the rotary engine in one piece is a MicroTech LTX12 with integrated LSM11 wideband O2 sensor. After many dyno tuning sessions this twin-rotor, single turbo RX-7 R1 puts out 460 horsepower and 337.9 lb-ft of torque at 17 psi on C-16 race gas.

To make sure the transmission held up under the newfound power, it was shipped to Pineapple Racing for a complete rebuild. The clutch assembly comprises a Pineapple Racing six-puck sprung-hub clutch and an HD pressure plate. Equalizing power distribution to the wheels is a KAAZ LSD. The engine revs a little freer thanks to an ACT Pro-Lite chrome-moly flywheel. A Mazdaspeed short shifter quickens the shifts and keeps the revs up in the powerband.

After a minor altercation with a mountain pass ditch, the car was off to Precision Performance Auto Body for a complete respray, including the engine bay, in Porsche arctic silver. Before the paint job began, Rotary Extreme Type F wide front fenders were bolted on. Between the fenders a Mazdaspeed-type carbon-fiber hood found a home. The nosepiece has been replaced with a Pettit Racing GTC nose cover. Filling the nose are '99 JDM Mazda front light combos. The headlights have been upgraded to an East Bear headlight kit.

Rotary Extreme was also the choice when it came to side skirts. Chuck decided to go with Type F carbon fiber skirts. Covering the rear tires are Pettit Racing Bonzai fender flares that are molded on for a clean look. Completing the JDM look are a set of '99 JDM Mazda taillights out back.

Filling the wide fenders are 17-inch CCW wheels, measuring 10 inches up front and 12 out back. Kumho Ecsta V700 race rubber sized 275/40 and 335/35 wrap the CCWs, front and rear, respectively.

The stance and handling of the Mazda come from a combo of Ground Control coil-overs with Eibach 2.5-inch race springs, 450 lb, front, and 375 lb, rear, with Koni Yellow adjustable shocks. The front sway bar is a Tri-Point Engineering Speedway piece with a 0.120-inch torsion bar. The rear control arms are from M2 Performance.

The braking system has been upgraded with cryo-treated rotors, Hawk Racing HP-Plus pads and Goodridge stainless steel brake line all the way around.

Driver and passenger are strapped in with Sabelt 3-inch, four-point harnesses. The standard gauge pod is joined with an Auto Meter A-pillar pod and a Pettit Racing steering column gauge pod. Defi Link gauges: boost, fuel pressure and exhaust temperature, fill the pods. The center console holds a Defi Link gauge controller and a Blitz Dual SBC boost controller and turbo timer.

Balancing his music needs with a racecar's low weight, the head unit was upgraded to an Alpine three-disc in-dash CD changer with Infiniti and Blaupunkt speakers in the stock locations.

By now we're sure you are familiar with Mazda's global marketing campaign-Zoom-Zoom. Chuck certainly is as his RX-7 sees plenty of road time. Whether it's on the wonderful network of nicely paved backroads around his hometown, lining up against other fast cars on the freeway or at the track. Chuck has been an avid autocrosser for the last seven seasons and the RX-7 runs competitively in the SCCA, Street Modified II class.

High school has a sneaky way of guiding you down particular paths. It is also a place to develop hobbies and obsessions. For Chuck Duncan his obsession led him into a Mazda dealership and on a 13-year journey. Sure the journey had a few bumps on the way but all his patience and hard work has paid off. This is one RX-7 any car enthusiast would cherish owning, no matter what brand or make of vehicle infused in their DNA.


Orange, CA 92868
Koyo Cooling Systems
Irvine, CA 92618
Pettit Racing
West Palm Beach, FL 33407
Polk Performance
Alexander, AR 72002
Alpine Electronics
Torrance, CA 90501
By Bill Klein
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