- Post is under moderation17 YEARS TO LIFE
While Mike kept busy building a reputation as a rotang builder, his Series 1 RX-7 sat in the corner of the workshop, waiting patiently. No fewer than four engine swaps and 15 years’ worth of development later, it now lives life as a 20B-powered award-winner.
Good things take time, and, sometimes, you need to try four different engines in the hole before stumbling on a winning combination. Words: Jaden Martin. Photos: Adam Croy.
/ #1979 #Mazda-RX-7-Series-1 (Savanna) 296bhp / #Mazda-RX-7 / #Mazda / #Mazda-Savanna / #Mazda-Savanna-RX-7 / #Mazda-RX-7-S-1 / #Mazda-RX-7-SA22C / #Mazda-SA22C /
Time waits for no man, let alone his project car. A fickle concept, time — the lack thereof means cutting corners or simply never completing a build, and an abundance can lead to overexposure of a good thing. Everyone uses their time differently, and it takes true dedication to embark on a long-term project. Mike Fitzgerald’s own tango with time saw a project that was only ever meant to be a simple engine conversion rapidly turn into an award-winning street car in only 17 years.
A keen fan of all things rotary, Mike has spent a good chunk of his years crafting a reputation as a skilled Wankel builder beneath the dim glow of fluorescent light-fittings in a Tauranga industrial-zone factory and, in that time, has, unsurprisingly, owned nearly every variation within Mazda’s RX family tree. After a quick succession of RX-2s, RX-3s, and multiple generations of RX-7s, he longed for the sleek ’80s styling of a Series (S) 1 RX-7, which is not only a great platform for a quick streetlegal track car but also one that has a long racing pedigree.
On the hunt for a clean enough example that wouldn’t demand a Reserve Bank’s worth of dollars, he knew the trick is to avoid rust-plagued shells and find a hearty runner.
So, when it popped up cheap, Mike snapped up this example for a steal and quickly got to work recreating the vision in his head. It now sports all the right aero protrusions that you’d expect from a car of the era. Inspired heavily by the factory Group C machines of the past, he chose to use the iconic front bumper and rear spoiler, with a modern twist through custom fibreglass dual-headlight pods and an RX-7 S3 rear bumper.
This original incarnation saw the RX-7 driven around for two years with a simple lick of Supersonic Blue Pearl paint and 12A bridgeport under the bonnet, before, eventually, it was torn down with the grand intention to convert it to a 13B.
During the Group C days, this was a controversial upgrade for the originally 12A-powered chassis, but it has since become a common choice for power-seekers. Mike’s plan would go one better, adding a nasty little snail on the side. But alas, this grand plan didn’t eventuate — time ticked by, and Mike had to make sacrifices while busy building other engines and cars for customers.
The RX-7 went untouched for five years while he chipped away at other things. He accumulated parts and built all sorts of gnarly packages, none of which made its way into his own project, until the perfect naturally aspirated (NA) 13B engine with an IDA was built, ready to be dropped into the car. This was it, he thought, the car would finally be whole again. Unfortunately, that was not to be the case. A customer strolled in and made an offer that couldn’t be refused — as the old saying goes, money talks.
It wasn’t all bad, though, as the urge in him to build the original turbo package was strong, and he promptly began prepping a JC 13B for a bit of snail-powered goodness. This one even made it into the engine bay before being ripped back out, rebuilt, and sold to yet another customer. However, perhaps that was never meant to be, as, after a bit of thought, planning, and a stroke of luck, Mike stumbled across his holy grail of engine options: a JC Cosmo 20B.
The import engine was snapped up in a heartbeat, as he’d always loved the sound they made and the idea of shoehorning a three-rotor into the RX-7’s small frame. The tango with time had paid off, and Mike decided that binning the twin-turbo set-up in favour of a raspy NA note was the best way to go: “The 20B makes so much power with a turbo [that] they almost become undriveable. I wanted a fast, reliable package that could be street driven with ease and [would be] a weapon on the track.” A wise choice indeed, as we enjoyed the sensual sounds we heard as the car arrived at the photo shoot.
The newly selected engine underwent a full freshen-up before it was slotted into its home inside the RX-7’s engine bay. The plates received a mild bridgeport to open up some flow for the street, and the worn old rotors were ditched in favour of new high compression S5 items with MFR rotor bearings and a freshly polished E-shaft. The conservatively built engine makes for a fast reliable street car that can and does get driven hard and is anything but a trailer queen, regularly making the trip from Tauranga to Manfeild and Hampton Downs — it also maintains summer driving duties when the weather plays ball.
In the suspension department, there’s a custom Bilsteinshock- and-King-spring combination. But, most important, when it comes to putting power to the ground, what would a rotary be without a set of classic Simmons wheels? Typical of the era’s show-car style, the Silver 17-inch FR17s are seven inches and 8.5 inches wide, shod in the ever-popular Potenza RE002s, while, lurking behind the classic five-spoke design, are 310mm rotors gripped by Wilwood Superlite four-pot calipers up front and S3 calipers down back.
The clean theme extends to the interior, which looks as if it’s rolled straight off the factory floor, thanks to an impressively tidy retrim. The original dash is devoid of any factory instrumentation and, instead, has been fitted with a Dash2 Pro electronic dash that displays all the car’s vitals via a Link G4+ Extreme. As for driver input, a Momo steering wheel, custom-fitted Tilton pedal box, and D1 Spec gear knob that leads down to the Mazda RX-7 S4 turbo five-speed all keep things in check.
The man behind MRT Racing, Mike has completed practically every component from the wiring to the fabrication and rebuilding of numerous parts. Of course, no good build would be without the help of a few mates, and he also credits the final product to taking his time — although it may be a lot longer than most are willing to spare — and changing his mind a lot to get the very best from each stage of the build. A statement we don’t doubt, as he claimed two awards at REunion for best engine conversion and best engine bay — this is a car very much worthy of such accolades.
The three-rotor 20B was only available in the 1990-’1995 Eunos Cosmo and was the world’s first volume-produced twin-turbo set-up, but Mike opted for running his NA to achieve the sensual sounds of rotary goodness.
WHEELS: (F) 17x7-inch Simmons FR17, (R) 17x8.5-inch Simmons FR17
TYRES: (F) 215/40R17 Bridgestone Potenza RE002, (R) 245/40R17 Bridgestone Potenza RE002
POWER: 220kW at the rear wheels
ENGINE: #Mazda-Cosmo-JC-20B / #Mazda-Cosmo-JC / #Mazda-Cosmo / #Mazda-Cosmo-20B , 2000cc, three-rotor
BLOCK: Mild bridgeported JC plates, S5 rotors (9.7:1), MFR bearings, polished E-shaft, S6 exhaust sleeves, modified oiling system, Racing Beat adjustable regulator
INTAKE: #X-Air-Performance over-the-radiator (OTR) panel intake, four-inch alloy intake pipe, 20B throttle body, port-matched intake manifold
EXHAUST: Two-inch three-piece headers, long primaries into three-inch collector, V-band clamp three-inch pipe, urethane mounts, Adrenalin R chambered resonator and eight-inch three-pass stainless muffler
FUEL: Custom 60-litre alloy drop tank, 1.5-litre surge tank, three Russell highflow fuel filters, Mallory 110 lift pump, Proflow 500hp (373kW) electronic-fuel-injection (EFI) main pump, Teflon braided line, XRP and Speedflow fittings, fuel-pressure regulator, custom fuel rails, S5 turbo primary and 20B secondary fuel injectors
IGNITION: #NGK plugs, MSD HT leads, six #Bosch coils, three two-channel ignition modules
ECU: Link G4+ Extreme tuned by Dtech Motorsport
COOLING: Toyo Racing S5 alloy radiator, alloy overflow tank, S4 oil cooler, electric water pump, electric fan, 20B oil-metering pump
EXTRA: Stripped engine bay, strengthened steering box, custom diagonal engine mounts, baffled sump, side-mounted alternator, Nascar carbon breather tank, custom alloy radiator shroud, heat shields, washer tank
STRUTS: Bilstein shocks, King springs
BRAKES: Tilton pedal box, Tilton master cylinders, L300 reservoir; (F) Wilwood Superlite four-pot calipers, 310mm rotors, Wilwood Polymatrix street/ track pads; (R) Mazda RX-7 S3 calipers, standard rotors
EXTRA: Nolathane bushing kit
GEARBOX: Rebuilt Mazda RX-7 S4 turbo five-speed, shortened gear-shift remote, and short-shifter
CLUTCH: Xtreme Motorsport kit
FLYWHEEL: Xtreme chromoly 10-pound
DIFF: S3 RX-7 LSD (4.4:1)
OTHER: 64mm driveshaft, custom driveshaft Hoops
Often overlooked, the interior makes a point of appearing as if it were still in the dealer’s showroom, with reupholstered factory trim in black marine vinyl along with grey cloth inserts, a new rear carpet, and refurbished plastics The custom fibreglass dualheadlight pods put a modern twist on an old classic, replacing the pop-up option it originally came with.
DRIVER/OWNER: Mike Fitzgerald
OCCUPATION: Automotive engineer
BUILD TIME: 15 years
LENGTH OF OWNERSHIP: 17 years
THANKS: Lance at RS Automotive; Grant at Penrose Motors; Dave, Mark, and Tony at Dtech Motorsport; Shane Hazelden Engineering; mates Josh Sargent, Andrew Daly, and Derek Jensen; Toby at GSS Performance; Noel at Nostalgia Motors; Reece at Regal Upholstery; Adrenalin R; Ronnie at RSL Automotive Performance; and Toby at BOP Polishers.
PAINT: Supersonic Blue Pearl
ENHANCEMENTS: RX-7 S3 rear bumper, Group C front and rear spoilers, alloy bash plates, custom fibreglass headlight pods, registration-light delete
STEERING WHEEL: Momo
INSTRUMENTATION: Dash2 Pro electronic dash,
ICE: Pioneer DEH-X head unit, Lanzar DC 64 pro-series front components, twin Pioneer 12-inch 800-watt-max subwoofers, Pioneer Class A amplifier
EXTRA: Reupholstered factory interior in black marine vinyl with grey cloth inserts, new rear carpet, refurbished plastic trims, modified steering-box mounts
POWER: 296bhp / 220kW at the rear wheelsStream item published successfully. Item will now be visible on your stream.