Rex with Flex
So nice was Ross, in fact, that despite what seemed to be a fairly painful stomach ailment he still came to meet us at his Hamilton Wholesale Cars Direct yard, having come straight from the doctor.
Incidentally, there are three more of these yards throughout New Zealand, and their prices are none too shabby! We wanted to know more about his giant-killing WRX race car, so he gave us the lowdown. Prepare to find out what it really takes to build a competitive car.
The numbers game
Four hundred and seventy-six dyno-proven kilowatts (638hp) from a 2.2 litre block does not come easily or, as Ross would find out along the way, without some expense. As with anything in life, improving upon an original design becomes an exponential exercise in both time and cost. For example, building a 298kW (400hp) engine will not simply cost twice what a 149kW engine would to build.
Try somewhere in the vicinity of triple the dollars, and so it goes. This 1997 WRX was never meant to become what it is today. TraNZam racing was where Ross’s original interest lay, but having missed out on the purchase of the late Ashley Stitchbury’s race car, Ross made the decision to buy the Subaru in 1999.
Due to business commitments and a lack of spare time, the Impreza WRX was only supposed to be a small project car built to compete in the super GT class series. But one race changed it all. Ross placed third on the grid in their first outing, which got the mental cogs turning, and one thing led to another.
At that time the modified engine was making around 313kW (420hp), which is no small figure in anyone’s terms, but to compete with the likes of Porsche Turbos and TVR Tuscans more power was required to remain competitive. This is where the fun really began.
The name game
While it’s state of tune back then was impressive enough, today the WRX runs a modified 2.2 litre block graced with a set of JE Racing Pistons for an 8.5:1 compression ratio. Carilio Con rods are reputedly the best of the best, so there was a set fitted to the bank of JEs, and:at the other end to the steel crankshaft.
The modified heads came courtesy of Udy Automotive, and spinning their lobes inside were a pair of reground camshafts. As it was, it was all fairly serious gear. Even the fuel delivery system had been sorted from the start. A puncture-proof bladder held the reservoir of 110-plus octane aircraft grade fuel.
Once out of the bladder, it stays in the custom surge tank until it is sent to the engine by two SX high performance fuel pumps, through the braided lines to the custom fuel rail. Here it is blasted into the combustion chamber by four Blitz 800cc/minute injectors.
Stopping is taken care of by AP Racing four-piston callipers and 330mm internally vented rotors. Gripping stuff. Suspension-wise things were pretty sorted. Kamtech had fabricated.anti-roil bars for both the front and reatfflhe car, both adjustable in eight different positions. Koni shocks that were ride height and rebound adjustable were looking after the damping duties.
Fat stripper
The firsi major revamp began with a fat reduction programme, Signart Design came to the party – and custom-built the full aerodynamic undercarriage, along with the carbon fibre and fibreglass replacement panels and fully adjustable rear wing The result was a 200 kilogram reduction in weight, and a massive improvement in stability and downforce.
Without the driver, the car now tips the scales at 920kg. Work the power-to-weight ratio and you should come up with a figure of around 1,94 kg/kW! Modified air intakes were designed for better flow capability, while a new bonnet scoop was utilised to extract as much hot air as possible. A new set of off-the-shelf extractors were employed to get the gasses flowing, and to handle the gain in power an AP Racing triple plate clutch was thrown in to cop the abuse from the enlarged EJ20.
Naked ignition
At this time the-WRX was. driving all four paws through an Album five-speed dogbox with straight-cut gears. This was, however, starting to show signs of wear so plans were in the pipeline to change to a more robust unit. Other modifications included a chromoly ditf brace for added structural rigidity, an onboard air jacking system courtesy of Kamtech Engineering – which also designed and manufactured the stainless exhaust – and a unique rear diffuser fabricated by Signart Design to reduce underbody drag and help with downforce duties.
By this stage the engine was making somewhere to the tune of 410kW (550hp). As per usual, power is something you are satisfied with for a while, but the urge to make more gets you in the end. So the next step was to prove a milestone.
Power Pack
By this stage everything was fairly well sorted, but with the power bug biting away the search for more urge had begun. Kamtech was given the go-ahead to fabricate a custom set of extractors to match its stainless exhaust already on the car. To keep up with the rest of the engine a new Garrett GT35 ball-bearing Turbo was installed, which currently runs at 21 pounds of boost.
The brains of the car were fitted at this point, with the addition of a MoTeC M48 with full data, logging capabilities, as well as a MoTeC advanced dash logger running, multi zones with track mapping, suspension diagnostics, shift light, warning light, G-force sensor and pressure sensors. The old Alburn dogbox was given the heave-ho, and was replaced with a five-speed. Hollinger with straight-out gears.
That’s still fitted today, having lived up to its expectations. To date Dunlop has proved to be reliable as far as racing goes, especially with the limited rim size. If wider rims could be sourced, then Obviously more opportunities for tyre; improvements could be realised, but that isn’t a major issue at the moment.
Expose yourself
Having to cop constant abuse under both racing and test conditions, the rods were proving to be not quite so reliable. On a fairly recent dyno run the boost was lifted to a stonking 30 psi.
The Carrillo’s obviously weren’t intended to cope with that sort of power, and subsequently some of them bent. Not good. Some people hold the opinion that on average you can add around seven kilowatts for every extra pound of boost you. run.
This means that at the time of bending the rods, Ross’s WRX could have been making around 544kW (730hp) at the flywheel! Due to the bending spree, a new set of rods – at around twice the price of the already ultra-expensive Carrillos – are being) custom designed to cope with the power levels generated. You might hear people comment that they’ve heard of standard engine internals handling massive power increases.
That may be so, but were you to place those standard internals under race conditions over and over, the story would have a different ending altogether. Plans are in the pipeline to generate a reliable 522kW x 700hp), and to do this new RSK B4 heads will be used due to their better flow capabilities.
A set of higher flowing 1000cc/minute injectors will also replace the current items, and a new suspension set-up consisting of four-way adjustable Ohlins will take care of handling duties to replace the tiring Konis. Other future plans will see a new transporter being constructed with full signwriting, for greater exposure while touring around the NZ racing circuit.
Record – breaker
The future’s brighter than ever for Ross, with one of his main goals to be consistently quicker around Pukekohe than the likes of Lighting Direct and Ray Williams in their Stuttgart specials. Ross and his team have spent the equivalent of a full off-season at the track just testing componentry and different set-ups for the WRX. Most of last season was actually run on what Ross calls the ’small’ engine, which, means 410kW (550hp) to us.
Ironically enough, it was with this so-called small engine that RosTmanaged to win an entire three-race meeting outright, as well as winning the modified class to boot. Impressive stuff-considering what he was up against. Fancy that then, a 2.2-litre turbo trouncing a 3.6-litre monster with twin huffers! Had the other 475kW (637hp) motor been installed at the time, the results would undoubtedly have been even more impressive.
But that no longer matters, as the focus lies solely on the future and the development of the aforementioned 522kW mill. Ross also happens to be motivated by the negative comments that so often circulate the race tacks at the Super GT meets, where no one takes a small capacity car seriously.
Lessons will undoubtedly be taught if Ross has his way, and he is also quick to point out that on a number of occasions he has already beaten plenty of Porsches? Other future plans for Ross include the building of a 22B-powered two-door-Subaru coupe-with a tubbed rear end for drag racing, and a drift car to have some fun in.
Quite possibly the most challenging goal Ross has is to make the aforementioned coupe the fastest Subaru in the world. It’s entirely possible, especially if he shows the same amount of determination as he has with this WRX race car.
1997 Subaru Impreza
Owner/Driver: Ross Rutherford
Engine: Subaru EJ20 with modified 2.2 litre block, forged steel crankshaft, Carrillo forged steel conrods, JE racing forged pistons, reground camshafts, modified and flowed cylinder heads, 8.5:1 compression ratio, Garrett GT35 ball-bearing turbo (21psi), TIAL 42mm external wastegate, MoTeC M48 engine management with mum zone capability, custom surge tank, 2 SX high performance fuel pumps, 800cc/minute Blitz injectors, custom fuel rails, full braided lines, puncture-proof fuel cell (110+ octane aircraft grade fuel only), Kamtech engineering custom stainless steel extractors and exhaust
Driveline: Hollinger five-speed manual dogbox with straight-cut gears, Subaru permanent 4WD, AP Racing triple plate clutch
Steering/Suspension: Subaru power steering, Kamtech Engineering front and rear eight-way adjustable roll bars, Koni dampers with ride height and rebound adjustment
Brakes: AP Racing four-piston callipers with 330mm internally vented rotors
Wheels/Tyres: Rays Engineering Volk Racing TE37 17×8-inch lightweight magnesium alloys with Dunlop 240×625x17-inch racing slicks
Interior/Exterior: Kamtech Engineering full chromoly tubular roll cage, MoTeC advanced dash logger running multi-zone capability, on-board air-jack switch, race seat, harnesses, electronic three-point fire extinguishe? and external powder extinguisher, Kamtech Engineering custom four-point air jacking system, Signart Design aerodynamic undercarriage with carbon fibre and fibreglass body panels, adjustable rear wing
ICE: N/A
Performance: 475kW (637hp) @ 6700rpm (Turbo Vehicles dyno), 656Nm (484lb/ft) @ 6000rpm; Best lap time at Pukekohe to date of 58.2 seconds.
Thanks: Waikato Times Motortimes, Vodka Cruiser, Wholesale Cars Direct, Kamtech Engineering. Signart, Mad Soundz, Firestone Direct, Turbo Vehicles Ltd, Udy Automotive, Avanti Racing Wheels, Fortress Fasteners, Toyo Tyres, Elf Lubricants, Spies Hecker, Generation 2000 Paint Finishers
Source: Performance Car