My car is a Subaru Impreza WRX Type RA. Some say the "RA" stands for "Race Altered" some "Rally Altered" some "Record Attempt" and some "Rally (Group)"A". I am not sure which if any apply. One thing is for sure, Subaru were required to produce at least 2500 WRX production road cars to enable them to homologate the impreza WRX for Group 'N' WRC (World Rally Cross). So they cleverly produced 2500 + highly modified road production cars so as they could legally enter a very hot car in Group 'N' and clean up! These cars were lightened (1170 Kg) using thinner panels, aluminiumm bonnet,thinner glass, no electric windows, no central locking, no sound insulation. The engines were closed deck design though this is not really required at moderate tuning levels, ( STI's had forged pistons too), bigger TD05 turbo, low ratio close ratio gearbox which gave acceleration of 0-60 in around 4.5 Seconds. The car will actually rev out in 5th gear at around 125 Mph. Acceleration is swift in all gears on boost and seems to benefit from short shifting between 5500 - 6500 RPM though my stock map will rev to 7750 RPM before limiting ! Interestingly my WRX was originally fitted with an STI engine striaight from the factory but the forged pistons were omitted.
The WRX has fixed 4 wheel drive through viscous LSD rear, and centre diffs, the front diff is open. The STI uses a DCCD to allow the driver to vary torque bias between front and rear wheels from the cockpit. The WRX Makes around 260 BHP stock and the STI 280BHP. The V2 engine was fitted with a 5th injector though this was never used. There are many basic tuning mods which will easily take the power to around 300-340 BHP. For additional power forged internals are recommended. The handling is very convincing though benefits from the many after market upgrades available. I have to be careful to keep mine fairly stock for the RGP class. I feel that the stock chassis is not that stiff (They would have been seam welded for group N) and that in itself is good enough reason to fit a roll cage, other aftermarket stiffeners and strut braces. Overall you get a pretty good basic motorsport car straight out of the Suburu factory for very little money. Any further mods are a bonus.