Let’s be honest, building a car, more often than not, is a terrible experience. Most of us have done it, or been involved in it at some stage in our lives. It’s often the wonderful dream when first embarked upon, the horrific nightmare when half way through, and the unwanted, neglected child when finally completed. Although there’s a plethora of TV shows and books chronicling build-ups, it is often hard to identify with hot rods, wheel standing ambulances and ice cream trucks bristling with big TVs. Where are the Japanese performance car builds? Well, a group of Kiwi mates — James Causer, Steve Alexander and Bren Parsons — have answered that very call with a DVD called 100% Driven. Not only do these guys show us some of the coolest import racing material from around the globe and New Zealand, they also follow the build-up of this 1994 FD3S Mazda RX-7.

“With minimal lag, the revs wind up and the car squats down on its rear haunches, shooting forward like a cheetah advancing on its prey”

Originally blessed with a lovely shade of pink, this FD has gone through a massive transformation over the last two years. Thanks to House of Kolor and expert painters Altered Image, the car is no longer a sickly pink, but a deep Majestic Blue hue. A custom vented bonnet was also added to aid in both looks and cooling when it came time for this machine to hit the streets. Being a promotional vehicle, the next logical step was to cover the sleek, sexy Mazda in as many decals as humanly possible. It is safe to say you won’t confuse this particular FD with any others on the road. In terms of rolling stock, the boys opted for a set of massive 19-inch XHP Boost rims, which measure 8.5 inches wide at the front, and 9.5 at the rear. A sticky set of Kumho tyres has been stretched over the rims to give it a good solid stance on the road. Although already a great handling car from factory, the boys wanted better and, of course, lower, so a Cusco catalogue was plundered and a very nice set of coil-overs and a pair of strut braces were ordered to do the business.

With awesome paint, big-arsed chrome rims and more decals than an inner city bus, this FD has no trouble standing out from the crowd. But while flashy looks are all good and well, by far the coolest thing about the 100% Driven RX-7 is its absolutely mental engine package, built by James (aka Jimmy) with help from Oliver at Frantik Motorsport. Opting to stick with the factory 13B-REW twin rotor motor, the boys knew that although big power was definitely achievable, it would require a good deal of hard work, and a whole lot of boost.

But before we get into all that technical forced induction bizzo, it pays to have a look at the block itself. As we all know, if a rotor isn’t built exactly right, it’s a goner. This particular 13B has been pulled apart, completely refreshed and then given a good dose of bridge-porting, which really gives the motor that extra kick up the pants when it comes to power figures. Before bolting all the housings and end plates back together, Oliver and Jimmy also installed a set of tough 3mm seals to go with all the brand new gear, thus ensuring this particular chicken cooker will be doing the business for a good while yet.

Now, back to the boost. What makes this particular RX-7 so interesting is that, unlike most owners who tend to swap out the problematic factory setup in favour of a big single, these guys decided to stick with the twin turbo system. In saying that, it is probably fair to say this car has two 'big singles’ to the tune of dual Masterpower GT37s. If you know your turbochargers, you will be aware that a GT37 is no small huffer. So what do you get if you have two of them punching boost through an angry, bridgeported 13B? Well, 442kW at the rear treads, that’s what.

“The twin GT37s pump air through an Autobahn 88 V-mounted intercooler kit, which includes all the piping necessary to get the air up into the intake plenum”

Of course, netting 600 rear wheel ponies isn’t as simple as whacking a pair of big turbos onto the side of a block; a whole host of gear is needed to get things running correctly. In terms of the induction side of the equation, the twin GT37s pump air through an Autobahn 88 V-mounted intercooler kit, which includes all the piping necessary to get the air up into the intake plenum. On its way there, it passes a pair of Tial blow-off valves, which tend to make a bit of a racket when relieving back-pressure, especially when following the raspy howl of a massive 60mm HKS external wastegate. On the exhaust side of things, a set of custom extractors has been made up by Frantik, which dump into a full 3-inch exhaust, complete with trick rotor-shaped Dytech muffler at the rear.

As most will know, a good engine package won’t be spinning up any decent numbers if it’s still running the factory computer. For this particular application the boys decided to use a tried and true MicroTech LT-10 engine management system, which runs everything from the Bosch coil packs to the high-flowing Walbro fuel setup — it even controls boost. Luckily for 100% Driven, Mazda decided to over-engineer its five-speed gearboxes, so when it comes to this FD’s driveline, all it needed was a meaty Exedy twin-plate clutch and an uprated LSD differential, and they were away laughing.

Nearing completion, there were only a few final touches to make in the living space of the now crazy coupe. Along with the obligatory Momo steering wheel and a host of gauges, the RX-7 also sports a very tidy half roll-cage and a surprisingly serious audio system. The booming setup comprises a Panasonic head unit, sending signal to a large Fusion amp powering a set of components, a set of 5x7s and a pair of thumping 12-inch subwoofers mounted in a custom enclosure in the boot of the car.
Standing around an idling car is great for those happy to talk a big game all day, but here at NZPC we are all about the on-road experience. After a little convincing, we managed to get co-owner, and 100% Driven presenter Steve to take us for a quick blast down the motorway.

Two GT37 turbochargers spooling up to 20-something psi is a noise you don’t soon forget. With minimal lag, the revs wind up and the car squats down on its rear haunches, shooting forward like a cheetah advancing on its prey. Sure, 750-odd horses may be a little excessive for the street, but damn, what a rush! Like the rest of the car, this monster engine build is chronicled in the 100% Driven DVD, so if you want to see this bad mother of a street fighter coming together, then be sure to check it out.

Driver Profile

Steve Alexander

Occupation: 100% Driven Presenter

Build time: 1.5 years

100% Driven thanks: Martin and Bianca @ Altered Image, Mark West @ CSA Wheels, Bruce and Steve @ Blair’s Tyres, Darlene @ House of Kolor, Tim @ Shores NZ, Magwarehouse.com Manukau, Ivan @ On The Limit Motorsport, Olli @ Frantik, DJ @ Sub Signs, DVD available at Whitcoulls and Sounds stores nationwide

Tuning Menu

1994 Mazda RX-7

Engine: Mazda 13B-REW twin-rotor, bridgeported, 3mm apex seals, 2x Masterpower GT37 turbochargers, 60mm HKS external wastegate, 2x Tial blow-off valves,  Autobahn 88 intercooler, alloy piping, Bosch coil packs, custom extractors, 3-inch exhaust system, Dytech rotor-shaped muffler, alloy radiator, Walbro fuel pump, MicroTech LT10 engine management system

Driveline: Factory Mazda 5-speed gearbox, Exedy twin-plate clutch, Mazdaspeed LSD

Suspension: Cusco adjustable coil-over shocks/springs, Cusco strut braces front/rear, factory 4-wheel disc brakes

Wheels/Tyres: XHP Boost alloys — 19×8.5-inch front, 19×9.5-inch rear, Kumho 235/30R19 tyres front, 275/30R19 rear

Exterior: House of Kolor Majestic Blue paint, custom vented bonnet, blue tints

Interior: Half-cage, Momo Race steering wheel, GReddy pyro meter, Auto Meter oil pressure, oil temp gauges, A’PEXi boost gauge

ICE: Panasonic head unit, 6.5-inch components, 5×7-inch Fusion speakers, 2x Fusion 12-inch subwoofers, 800W Fusion amplifier, custom boot enclosure

Performance: Dyno Power — 442 kW @ wheels