Michael Busby’s RX7 FC3S gravel rally car

DSC_0014Do it once, do it properly. This simple combination of six words is often thrown about nonchalantly when choosing a path to take and implies that whilst the easiest and cheapest route may seem attractive at first, in the long run it is always better to do something properly the first time, and need never do it again. Do it once, do it properly has quality at its core, be it the parts selected or the time and energy invested into the physical work.

DSC_0061Cars, especially competition vehicles, that are built with this ethos are usually quite special; their owners’ pursuit of perfection often produces a result much greater than the sum of its parts, no matter how special those parts may be.

DSC_0610And so it is with Michael Busby’s Series 5 FC3S Mazda RX7 gravel rally car. Before my ride I knew it was a special car with some special parts, and it certainly felt that way as we whined, burbled and brapped our way through the quiet Sunday afternoon backstreets heading away from Busby’s workshop.

DSC_0149But as we turned onto Montacute road and at precisely the point where urban sprawl miraculously morphs into undisturbed bushland and the tarmac becomes deliciously twisty, the RX7 transformed into something that instantly smashed every preconception I had. The turbine like smoothness and linearity of the power delivery, the rapid-fire gearshifts and the way that the MCA 50mm adjustable suspension, still in full gravel setup, felt so safe and planted had me speechless, emitting girlish giggles of disbelief that only grew with every passing kilometre. It was that much fun.

DSC_0623At the heart of all this is the turbocharged 13B twin rotor, a powerplant famed for its Sean Connery-esque power delivery. Given the nature of turbocharged cars from the 80’s I was expecting a sudden thump in the back as the car came on boost, but Busby’s RX7 couldn’t have been more different. The turbocharger, a rebuilt stock item, works in perfect harmony with the linearity of the rotary engine, delivering a characteristic more in common with something naturally aspirated. The revs just seem to keep building and building, the high-pitched rotary whine getting louder and louder until you think you’re about to split into another dimension, which almost happens given peak power is produced at a whopping 8000rpm.

DSC_0650PRC rally rules are quite restrictive and a basic extend port is all that could easily be done within the regulations so the RX7 won’t be headlining any dyno competitions, but it has easily more than enough power given the gravel surface the car is built to compete on. The engine’s specs may not be far from stock but everything is fresh and the Microtech ECU has been carefully tuned by Jason Unkovich at REVS, and you can feel it every time the accelerator is given a jab. So far it has proven itself against every preconceived exploding rotary story, too.

DSC_0639The single best component of the car is without a doubt the close ratio, straight cut H-pattern Modena Engineering dog box. There’s no hiding that it’s a big dollar component, but its value is realised with every gear shift. The throw is so ridiculously short that it makes an MX5 feel like an old bus. A flick of the wrist, not more than half an inch in each direction, see’s the billet lever home into each gear with a positive, metallic click. This means lighting fast, clutchless gearchanges that take your breath away. Gearchanges so fast that on hearing the car coming you’d swear it has an F1 style electronically controlled automated manual.

DSC_0160When ordering the gearbox Busby and his father put a great deal of effort into calculating their desired ratios, and from the passenger seat it feels like they’ve nailed it. First gear is reasonably tall to cope with gravel stage starts and to deal with wheelspin out of tight corners, but each gear after that comes flying thick and fast, one after the other. The sheer amount of noise it generates is something else; you can hear the gear whine coming for miles, long before any exhaust noise reaches you. Conversation is almost impossible at 60km/h, and the noise is almost painful at 100 with bare ears. It’s a macho sound; however this is definitely a car where recce headsets are a necessity.

DSC_0968For Busby, who’s day job is as an advanced driving instructor for sponsor Driver Skills Australia, rallying the RX7 occupies almost every waking hour. At the age of 20 he made the decision to get off the public roads and get involved with organised motorsport, and invested his time in building an AE86 Sprinter to compete in the first Rallyschool Australian Junior Challenge in 2011, which took him as far as competing in that year’s WRC round at Coffs Harbour alongside the likes of Loeb and Lattvala.

DSC_0934Realising that he had a genuine shot of winning the 2WD challenge with just a little more car speed that the Sprinter couldn’t quite deliver, the RX7 was purchased from Queensland over Christmas 2011. Its first outing was at Rally Calder in March 2012, where in muddy conditions Busby and co-driver Steve Fisher finished on the 2WD outright podium, qualifying for the 2012 Junior Challenge final in the process. But unfortunately the rest of the season wasn’t as kind. A challenging Rally SA saw the car sustain damage in diabolical conditions, and a heavy landing whilst leading the Junior Challenge final at Coffs Harbour broke the rear subframe, ending their chances at the title.

DSC_0919But after the disappointing season that was 2012, Busby is determined not to let the same thing happen again in 2013. Come the first event of the year, the car will be in better shape than ever. Busby’s father Peter, an engineer by trade with a long history of building his own circuit racing cars, is working to remove any weak spots – for example, the chance of electrical problems has been reduced by rewiring the car and fitting Deutsch connectors which offer greater protection from mud and water.

DSC_0571A plethora of new suspension parts are on their way which will give the ability to fine tune the handling of the RX7 to a greater degree, and summer testing is planned to make sure that the RX7 has hit its sweet spot come the first event of the year. The effort hasn’t been solely relegated to the car either – Busby and Steve have spent time with experienced co-driver Bernie Webb in an effort to improve their pacenoting. 2013, as they say, is looking bright.

DSC_0154Enjoying the RX7 as we did that day is a rare occurrence, because how this car drives is usually compared alongside stage times and in the heat of competition. It’s rare to drive this car simply for the sake of driving it, and it’s rare to be sitting in the co-drivers seat with the frame of mind of simply enjoying the experience. And I guess that’s what made our drive special. The next time this car comes out of the garage, it will be flung down a gravel road, most likely sideways, at speeds that would make your mother cringe. But for our drive it was just us, the RX7 and an empty stretch of road. Perfection.

Words and photos by Andrew Coles.

Engine: Twin rotor 13B Turbo with basic extend port. PWR Radiator.

Driveline: Modena 5 speed H pattern close ratio dog box. Xtreme single plate racing clutch. Mazdaspeed 1.5 way LSD.

Suspension: 50mm adjustable MCA front and rear.

Brakes: Factory Mazda alloy 4 pot. Motul race brake fluid with Project Mu pads.

Steering: Converted to non power steering.

Wheels: 15×6.5 Speedline Corse aluminium gravel wheels with Kumho ARC control tyres

Bodyshell: Reinforced FC RX7 shell with tower to tower Walker Chassis multi point steel roll cage.

Electronics: Microtech Engine Management with digital dash unit and Turbosmart boost controller. Competition spec rewire with Deutsch plugs used throughout.

Thanks to: (In Busby’s words) A huge thanks to my Dad – the engineer, mechanic and team manager. My service crew for the stupid amount of work they’ve put in, particularly in the leadup to Coffs Harbour this year. Mark Butcher at Driver Skills Australia. Jason Unkovich at REVS. Matt Stanton at Tyrepower Kensington. Katie Young at Savanna Motorsport. Barry Lowe at BJ Auto’s. Andy at Autosport.

More drive stories on Any Given Reason:

Toyota 86 GT


Nissan R35 GTR


DSC_0941DSC_0661Old mate in the V35 couldn’t stop it with the driveby’s during our shoot.

DSC_0600DSC_0054DSC_0095You know they’re serious when there’s Lancia 037 posters in the shed.DSC_0585DSC_0030They’re both 2 door, 2 seat, rear drive Mazda sports cars. So why can’t mine keep up?DSC_0576DSC_0556DSC_0024You discover the most beautiful houses when trawling country lanes for photo spots.

DSC_0177The trick to getting a rotor to last is to run pre-mix oil in the fuel, 2 stroke style. You can’t tip the oil straight in the fuel filler, so each time you visit the servo you need to pre-mix a jerry, and then tip it in. We got some strange looks filling a car with a jerry at a servo. The RX7 is quite thirsty, especially when you start to lean on it a bit.

DSC_0553DSC_0536DSC_0179Rotors attract the wrong kind of girls.


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  1. KEEN AS RACING January 10, 2013 Reply

    Another amazing write up about a even more amazing car good job boys and best of luck for 2013

    • Andrew Coles January 10, 2013 Reply

      Cheers mate! 2013 looks set to be a cracker year :)

  2. Kishan January 27, 2013 Reply

    We are entering 2 series 1 mazda rx7s in the East African Safari Rally.
    Would you mind if we called you just to ask you for advice since you already rally

    • Andrew Coles January 30, 2013 Reply

      Hi Kishan - I have sent you an email, let me know if you don't receive it. Cheers, Andrew

  3. oneil November 18, 2013 Reply

    hey guys i am about to build a similar fc rallycar thanks for the info because i was having second thoughts ,but after seeing this its full steam ahead ....rallying is big in jamaica .....but only a few has ever tried rallying rx7,,..

    • Andrew Coles November 27, 2013 Reply

      Hey! Thanks for reading, and cool news on your RX7 project! I must admit I know exactly zero about rallying in Jamaica, is there a link or something where I can find more info? Cheers, Andrew

  4. oneil November 27, 2013 Reply


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