[this article appeared in Auto Engineer magazine]Drifting is an “extreme” motor sport when it comes to the punishment dealt out to the vehicle however to the uninitiated it can appear to be simply legal tyre burnouts. The sport has spread very quickly around the world and with that growth has come the science of building the perfect drift car.
Garage7, located in the Adelaide Hills, is a leading performance workshop specialising in the development and modification of Japanese imports for drifting and other types of motor sport. Co-owner Declan Walsh, who started the business in 2008 with partner Luciano Notari, explains that drifting is very unique and has its own complexities,
“The drivers perform qualifying runs where they are judged on speed, angle, line and style. The judges have strict criteria about line and clipping points at the start of the event. The required line is not always the racing line and often drivers will be asked to put the car on an awkward line or get as close to a concrete wall as possible. They are given a score and placed into one on one battles. Each pair of cars has two runs in which the drivers take turns leading and chasing. It is the chase car’s job to emulate and improve on what the driver in front is doing. It’s all about a driver’s ability to adapt in a split second to the car in front while both cars are in a complete state of oversteer.”
Drift Australia competitions start with a round of 32 entrants which is cut to 16, then reduced after each face-off from eight to four to two cars to determine the ultimate winner.
Declan says this environment is incredibly harsh on the whole car,
“Engines run at very high temperatures because they are held at peak rev’s and with the car being driven sideways there isn’t good air flow through the radiator. The drive train is constantly changing. Every time the handbrake is used everything from the clutch back to the differential comes to a complete stop then it is put under maximum load when the brake is released, and that is happening numerous times each lap. The non-stop changes of direction create unusual suspension loading. Factory Ackerman angles work against the car during drift and cause the trailing wheel to be in a state of complete scrub out – not following the road. The violent direction changes place a lot of stress on the power steering components which is why power steering fluid coolers are common on drift cars. Add to this the fact that every now and then the car is colliding with the wall or the other car.”
The cars of choice have been high powered Japanese front engined sports cars with rear wheel drive: the Toyota AE86, Nissan Silvia S13 and S14 models, Nissan Skyline R31-34 (non all wheel drive models). More recently the Nissan 350Z and 370Z have appeared on Australia’s circuits with a “Z” winning the 2012 Australian Drift Grand Prix, and a few Toyota FT86’s have started turning up at events. Declan says turbo charging is common in the sport but what is more important than horsepower is reliability and that is where the attention to detail in the build program is so important.
When a donor car arrives at the Garage7 workshop is is stripped of all unnecessary weight. The shell is then seam welded. This is very necessary as it will undergo severe twisting every time the car changes direction on the track. Some owners opt for tubular front and/or rear ends for more tyre clearance, ease of maintenance and overall strength. In goes the CAMS-approved roll cage which is usually made from the lightest of the hi-strength steels such as chrome moly. The next stage is the suspension,
“One of the things many people assume about drift cars is that they are set up to slide easily. That is, slippery tyres with high tyre pressures, overly stiff suspension and snappy wheel alignment. In reality it is the exact opposite. The cars are set up to maximise mechanical grip. Dampers are tuned to ensure the tyres make contact with the track at all times. Adjustable suspension arms and linkages are used to dial in wheel alignments that maximise traction and drive, even under full slip. The car should be balanced and predictable. The driver needs to be able to put the car where he wants it, accelerate up on an opponent’s door and then slow down mid-slide or change direction at a moments notice. Many drift competitions are enforcing tyre regulations to level the playing field because the drivers would prefer to run on very soft compound semi-slick race tyres if they were allowed”, adds Declan.
The next part of the car requiring dramatic change is the steering geometry. In order to have the car perfectly balanced and receiving maximum grip the steering angles and Ackerman angles are completely reworked. Then attention is turned to the engine. One of Garage7’s star customers is multiple drift champion Simon Michelmore who has been standing on podiums and collecting silverware since 2004. His Nissan Silva S14 has a RB26/30DET powerplant – an RB26 twin cam head bolted to an RB30 3.0L bottom end with a single Garrett GT3582R turbo. It produces 397 kilowatts at the rear wheels at 22psi boost. The bottom end – the block, crank, rods and pistons – are all second hand factory Nissan parts and, incredibly, despite years of extreme racing it has never been rebuilt.
Drift car engines run on ethanol fuel (E85) with an octane rating of up to 108 RON and Declan says this allows them to push the engines harder,
“We are able to produce much more power and torque with a far greater safety margin than on standard petrol. As well as this, it’s a very clean burning fuel. High performance and green.”
The level of detail at Garage7 goes right down to what lubricants they use in the engines and Evan Daws, who is responsible for sourcing performance parts, says they only use Anglomoil,
“We were originally introduced to Anglomoil by Simon who had been using it for a while and was very impressed with the results. Anglomoil make very high quality oils which are ideal for high performance engines. We use Anglomoil Roadmaster 500 API SN 10W/40 fully synthetic for the drift cars as well as our non-motor sport customers. Unlike other oil products that end up with water build-up and sludging in the engine due to the E85, the Anglomoil product is able to handle the demands of this racing fuel. With Simon’s turbo charged motor we build the engine and look after the engine management and we dyno tune it as well. It runs faultlessly and there is no scoring in it. You can tell the difference in the Anglomoil product from others because when we drain it from the engine it comes out cleaner than any other performance oil we have used. Other oils are often prone to burning over time or wear and tear. Here is a local Australian company making a better product than the big multinational oil companies.”
The final ‘build’ stages include rewiring the electrics in a minimalist fashion to save precious kilograms from the overall weight of the car, the engine management system and dyno tuning.
“A good ECU is invaluable as it gives us the ability to data log during an event and make instant changes to improve performance. Our ECU of choice is a Link G4, or Vipec, as they allow us the ability to create customised controls and maps for just about anything you can think of. Then it’s on to the dyno so that we can tune the engine. Reliability and consistency is the goal. Most competitive drifters are happy with anything over 300 kilowatts at the rear wheels. Interestingly, you can still make a car drift successfully with as little as 80 RKWK.”
The testing session continues at the race track where wheel alignments and damper settings are fine tuned to suit the circuit conditions. Garage7’s latest project is an all-new car for champion Simon Michelmore,
“We have started work on a new Nissan S14 Silvia which will run the RB26/30DET engine with a few upgrades. It will have a tube frame front and rear end and heavily modified steering. We have plans of doing some special things such as boot mounted radiator with side ducts.”