Australia’s recent Subaru Nationals, or SubiNats as the locals prefer, showcased some the fiercest competition I’ve seen at a club level meet. Seriously, how often do you see billet blocks and predominantly carbon fiber chassis competing for outright honors at anything other than a pro event?

So what does it take to come out on top in such a competitive racing environment? Let’s find out firsthand by taking a closer look at SubiNats 2017’s champion car. The driver, Nev Scott, was more than happy to open the doors and lift the hood on the Car Mods Australia (CMA) 2005 Subaru WRX STI.

I’d forgive you for assuming that the time attack-inspired build was planned from day one, but it’s not the case. This WRX started life with much humbler duties, and for the first few years of its life it served as daily transport for CMA’s Daniel Callow, who still owns the car.

The first transformation began way back in 2007 with the standard go-fast bits and pieces added almost as soon as it entered Daniel’s garage. A larger exhaust, intercooler and turbo were added to Subaru’s already capable STI package, pulling together the perfect combination for a tough streeter.

However, the game plan would change completely just two years later, spurred on by Daniel’s creation of Car Mods Australia. Once the online business kicked off, Daniel decided it’d be the perfect time to get a little bit silly on the WRX by making it a test car for new parts.

The WRX served as an excellent way to showcase some of the products CMA had on offer, but Australia’s strict laws and overzealous police really capped what was achievable if the car was to stay on public roads.

The next step was obvious. Daniel had the perfect excuse to create something that he’d always dreamed about – a dedicated track car.

Continuously throwing in additional parts sure was a lot of fun, but if the WRX was to have a chance at success on the tarmac, a more serious approach would be required. Reliable horsepower was a large part of the new game plan, so it made sense to start under the hood.

While the original engine was a solid street performer, it wouldn’t survive long under the constant mechanical abuse it’d be subjected to on the race track. It was time for something up to task.

A Cosworth 2.5-liter long motor paired to a Garrett GT35R turbocharger was dropped into the bay. While the majority of components under the hood have been changed or tweaked since those early days, this original foundation still remains today.

According to Nev, it’s an entirely different car to when the race motor was initially dropped in; it’s stronger, more reliable and makes bucket-loads more torque and power. These improvements are thanks to the team’s philosophy that nothing is ever perfect.

After consulting with Dave Lenthall from GT Auto Garage and Will Chang of JHH Performance Engineering, the group decided it was time to freshen the car up with a revised engine package.

A Dailey Engineering dry sump kit was installed to further the reliability of the engine by keeping oil temperatures and pressures consistent, even while racing in some of Australia’s harshest (read: searing hot) conditions.

Due to time constraints in preparation for the World Time Attack Challenge, the engine remained as a semi-closed deck block instead of the preferred closed option. While this limits the maximum boost to around 20psi (1.36bar), the engine still safely produces over 360kW (482hp) at the wheels.

The bay is dominated by a Process West dream list including a v-mount kit, oil cooler, fuel surge tank, inlet manifold and fuel rails.

A Hypertune throttle body, Cusco strut brace and a Perrin master cylinder stopper round out one of the best-presented race car engine rooms I’ve come across in a while. The aftermarket paradise and upgraded fuel systems are all controlled by a MoTeC M800 ECU.

Unlike the majority of top teams, CMA’s WRX still retains its OEM 6-speed gearbox, which runs into a Cusco 1.5-way mechanical LSD in the rear. A sequential box is on the wish-list and likely to be included in the next major overhaul.

Horsepower is only useful if you can transfer it to the black stuff efficiently, and the next part of the grand plan involved getting wide and introducing a lot more rubber to the project.

While the engine was out, the chassis was stripped back to bare metal and a roll-cage was welded in. At the same time, the team removed anything unnecessary to reduce weight; a full carbon fibre roof was installed and the glass windows were replaced with polycarbonate equivalents. The interior is spartan but functional, and the car’s weight was reduced to just 1270kg (2800lb) including the new cage.

It was important to Daniel that the car resemble its original look, and an APR wide-body kit struck a happy medium between going super-wide while still retaining the original lines. The kit was further modified by the team to add an extra 15mm of width to each corner of the car.

With the APR body kit fitted, the WRX had some deeper fenders to fill. To that end, a set of RAYS Volk Racing TE37SLs in 18×10.5-inch sizing do the job nicely.

Not only did the TE37SLs meet all of the performance requirements, they are, in Daniel’s opinion, the ideal way to finish off the clean but tough JDM-inspired look the team was chasing.

A set of Cosworth 6-pot calipers and 365mm slotted rotors keep Nev braking as late as possible, while Circo Racing pads, supplied by Motorsport Brakes, are the final piece of the braking puzzle.

In the suspension department, the WRX runs TSS Fab front and rear subframes, and an array of its adjustable links and arms. Cusco Zero 3X competition coilovers control the cars ride and have proven to suit the setup well. With the WRX up on a hoist, or your nose on the ground, you can see the entire Whiteline suspension Subaru catalogue replacing all bushes, sway bars, links and mounts on the underside of the car.

The car’s aero looks quite tame compared to some of the more radical time attack builds currently being seen in Australia and elsewhere around the world, but it all works remarkably well.

That said, a revised package is currently under development and will take full advantage of the leaps and bounds made in time attack aero over the last few years. I for one will be very interested to see how far the team are willing to go, and how they plan on retaining the clean look that’s defined the CMA car thus far.

So how did CMA’s Subaru win top honors? On paper, the WRX certainly wasn’t the most powerful car of the weekend, nor the lightest, nor the car with the most advanced aero.

In my mind, it was the entire team’s experience that gave them the edge needed to come out on top. When coupled with the WRX’s rock-solid reliability, the competition were never going to have an easy day at SubiNats 2017.

What have I learned from taking a closer look at the CMA team? In racing, nothing beats experience. Except of course luck.

Matthew Everingham
Instagram: matthew_everingham
matt@mattheweveringham.com