Impreza Spec C
http://www.evo.co.uk/carreviews/evocarreviews/241432/subaru_impreza_wrx_sti_spec_c.html
JDM Market only. uses the 2.0L engine (VS the 2.5L engine in UK cars) with the Twinscroll turbo as found in the JDM STI. approx 30kg of weight saving due to no rear boot carpet, light weight windows, light weight alloy panels etc.. It has a massive water tank for the I/C spray in the boot, bespoke spring and damper setup, among a load of other stuff. See the article above.
Think of it as like a 911 GT3, lightenned, with extra power over the regular STI
Spec C Type RA
Based on the Spec C, but more geared up for use in rallying. Very Very Rare with only 350 ever made.
http://www.gtr.co.uk/forum/110458-two-impreza-spec-c-type-ra-just-arrived-japan.html
Notice the map holder in the passenger side. Over the Regular Spec C it has sti rear rose jointed trailing arms, 19mm arb and 4 position rebound and compression adjustable dampers, and different wheels (light weight Enkei items as used by the Litchfield Type 25 Hawkeye) Also has a larger intake manifold
One for sale
Here
That one has 400bhp + which is dead easy (see
Power Station)
No more power than the Spec C i dont think so more like a Clubsport Spec 911 GT3.
Impreza S204
http://www.insideline.com/subaru/impreza/driving-the-ultra-sti-subarus-impreza-s204.html
Very rare with only 600 built.
Has more power than the Spec C due to the modified turbo, remapped ECU, larger compressor wheel in the turbo, revised intake etc.. Uses BBS alloys with Pirelli P Zero Corsa tyres. Carbon fibre backed bucket seats, rear spoiler specific to the S204. Carbon fibre front splitter.
Its predecessors are the S202 and S203.
Created by STI aimed at being the "Ultimate Impreza"
Impreza Spec C RA-R
http://www.evo.co.uk/carreviews/evocarreviews/206850/subaru_impreza.html
Uses the same 316bhp higher power engine of the S204 ,6 pot brembo brakes, modified inverted struts, ‘lowdown’ springs, ‘pillow ball’ bushes and thicker anti-roll bars. Think of it as like a 911 GT3 RS.
Very, Very rare with only 300 being built. Only officially sold in Japan.