There’s rare, and then there’s ultra-rare. The Subaru Impreza WRX STI Spec C is rare. But the WRX STI Spec C Type RA-R is a car you might not ever see in real life, because so few of them were made. For years, Subaru didn’t own one of these cars – an omission recently corrected by the company, adding one of only a few hundred ever built to its collection. 

Racing rules are the only reason the 2006 Subaru Impreza WRX STI Spec C exists. It’s what’s known as a homologation special, a road-legal car produced in limited series to meet a race-sanctioning body requirement. And the Type RA-R is a Japan-only version of the Spec C. Where the Spec C is loud, brash and rough, the Type RA-R is a little more civilized.

The rules for Group N rally cars dictated that Subaru needed to offer the buying public a production version of the rally-racing WRX STI. That’s what the Spec C became – lighter, faster and more raw than other WRX models, it was a motorsports starter kit. A buyer just had to add safety gear to hit the track. The upgraded engine and suspension, more robust structural bracing and weight reduction were all in place.

2006 Impreza WRX STI Spec C Type RA-R
The ultra-rare 2006 Impreza WRX STI Spec C Type RA-R at Colorado’s largest annual enthusiast event, the Rocky Mountain Subaru Festival.

A Strong Foundation

While the changes made the Spec C outstanding for drivers, Subaru knew some buyers would appreciate all the normal WRX features paired with the increased performance. The Type RA-R kept the thinner-gauge roof stamping, the aluminum trunk lid and lightweight glass. The tubular cross-car beams and reinforced strut-tower braces all remained, too. Exclusive to the RA-R were enormous 6-piston Brembo®¹ front brake calipers, 18-inch wheels and revised anti-roll bars. Peeking underneath, one can spot the exclusive suspension parts by their pink color scheme. Also, the height of the RA-R dropped by 15 millimeters compared to other high-performance Impreza models, lending sharp response to driver input.

The classic turbocharged SUBARU BOXER® 4 was breathed upon by the performance gods, too. The Spec C powertrain was made from top materials. The standard turbocharger was replaced with a low-friction ball-bearing unit with a larger diameter for more airflow, and the tubular structural crossbar braces increased rigidity over the standard solid outfitting. An optional carbon-fiber rear wing was also offered, but the styling and exterior remained relatively subdued for a car packing such high capabilities. 

Color choices were limited to white, blue or yellow, and just 50 yellow RA-R models were produced. If you’re looking for a quick way to identify an RA-R, try to spot the center section of the front grille. A thin red stripe in the inner grille surround marked these special cars from the factory.

Power Up

The unique Spec C engine control unit and camshafts gave the 2-liter EJ a strong, flexible 320 horsepower and 318 lb-ft of torque. A high-performance exhaust, meanwhile, was part of the Type RA-R outfitting, lending a throaty voice to the muscular performance.

One of the most intriguing performance features is the unique intercooler water spray. A water tank and spray nozzles are onboard, so the engine management keeps intake manifold temperatures in the proper range for reliable power. Crank up the boost and a mist of water is sprayed on the fins of the intercooler, using the cooling effects of evaporation to further reduce the temperature of the air flowing from the turbo to the engine. The results of the tuning give the Spec C a wider powerband and willing personality. In fact, drivers lucky enough to test out the RA-R when it was new often commented on the abundant torque – from 2,500 rpm all the way up to the 8,000 rpm redline.

Take a closer look behind the 2006 Impreza WRX STI Spec C Type Ra-R

Options Abound

Even with its special outfitting, buyers could choose additional options to make the Type RA-R their very own. Standard sport seats were bolstered aggressively to keep occupants in place, but optional Recaro®² buckets were also available for the hardcore set. The standard 18-inch wheels were lifted directly from rally duty and finished in white. And, finally, optional BBS-style wheels were available, carrying a subtler silver finish.  

The 2006 Impreza WRX STI Spec C Type RA-R is a car anyone may walk right by. Subaru chose to let its performance do the talking, so it’s not as visually brash as you might expect. But looks can be deceiving: On every level, this is truly a distinctive vehicle.

2006 Impreza WRX STI Spec C Type RA-R
The 2006 Impreza WRX STI Spec C Type RA-R can be identified by a thin red stripe outlining the inner grille.


¹ Brembo® is a registered trademark of Freni Brembo, S.p.A. ² Recaro® is a registered trademark of RECARO Holding GmbH LLC.