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2007 Subaru Impreza - X Is For Excellent

Rally To The Cause

Text By Colin Ryan, Photography by Steve Demmitt
2007 Subaru Impreza Spare Tire

He and his co-driver-the brave mensch, who reads out the course notes, telling him whether a left- or right-hander is coming up and how tight it is-usually Chrissie Beavis, sit in Recaro Pro Racer seats, fitted with HANS head and neck restraint systems-strapped in by Sparco harnesses and surrounded by not much other than some stock gauges. Because this is a race car, all extraneous weight has been jettisoned, but there is an 18-point rollcage, of course, custom-built by Syms. And rally cars have been known to roll. Quite often, a bunch of spectators will help get a car right side up again, so it can complete the stage.

TEIN Group N coilovers (genuine three-way damping force adjustable) make up the suspension, along with stock STI antiroll bars. The Group N name refers to the FIA class of rally car, where participating machines have to be similar to the street models on which they're based.

2007 Subaru Impreza Tein Group N Coilovers

But, one of the changes allowed pertains to gearbox internals. A, more or less, free hand is given, provided the homologated ratios and gearbox pattern are respected. So teams can use dog engagement gearboxes that allow for quicker shifts.

The dog box here (operated by a factory STI shift lever) is a Syms custom special, holding five ratios. It couples up to stock STI axles and a limited-slip differential via a Syms/Ogura Racing twin-plate carbon clutch and an Ogura Racing flywheel. Syms has played with the electronic locking center differential to squeeze out all the advantage it has to offer, but the exact details have to remain within the realm of speculation.

2007 Subaru Impreza Evo Corse Wheel

That bit earlier about how to make a winner? There's a piece of the jigsaw missing. Papworth is tight-lipped about some of the work done, especially where the engine is concerned. Understandably so: There's no point spilling the beans to the other teams. All he's prepared to divulge is that the well-known and well-loved 2.0L EJ flat four has been bored out to 2.2 liters. The custom engine parts made by Syms are as follows: camshafts, connecting rods, pistons (aluminum), piston rings, crankshaft, valves, valve springs, retainers, cam gears, exhaust, and headers.

Syms took the throttle body, intake manifold and oil pan, and performed modifications on them. The head has also been ported and flowed by Papworth's team of engineers. A custom-made turbocharger, blow-off valve, and wastegate form the forced induction system, kept in check by an FIA-regulation 34mm restrictor, and cleaned with a K&N 57i air filter. The intercooler and pipes are a mix of Syms and Crawford, while the boost controller is made by Motec with some secret tweaking by Papworth and posse. Out went the stock radiator and oil cooler, replaced by Syms specials. It's a similar story with some of the hoses, and an HJS catalytic converter replaces the factory unit.

  • 2007 Subaru Impreza Cockpit
  • 2007 Subaru Impreza Coralba Giant Rally Computer
  • 2007 Subaru Impreza Engine Bay

Papworth claims 315 hp at 4,000 rpm and a heaving 510 lb-ft of torque at just 3,500 rpm, great for pulling the car out of muddy bends. Along with colleague Masahiro Kobayashi, he tuned the Syms/Motec ECU. This brain coordinates Syms Race spark plugs and 650cc/min fuel injectors, plus a Bosch 305lph fuel pump. The ignition, plug wires, fuel regulator and fuel rail remain stock.

Rallying hands out plenty of punishment to drivers, co-drivers, and cars alike. That's why some of the mods aren't necessarily for greater speed so much as longevity. The body has received attention in the form of extra welding and strengthening. For the final flourish, it was painted in a base black with decals-of Rockstar energy drinks, the main sponsor-supplied and fitted by UC Graphics of Quail Valley, Calif. Papworth now puts the car's value at $185,000.

By Colin Ryan
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