A week or two ago on the forum I asked the difference between Phases... I take no credit for what I am about to Paste as it came from a source on a different group and he had nabbed it from a forum. Anyway here ya go.
Dimensions, Weight & Performance
Length/Width/Height - 3975/1690/1410 mm
Wheelbase - 2430 mm
Tread front/rear - 1440/1415 mm
Kerb weight - 1220kg for GTI-RA (Road Edition), 1190kg for GTI-RB (rally Edition)
Seating capacity - 5 (really 4)
Minimum turning radius - 5.2 m
Maximum speed - 223 kph+
Acceleration - 0-100 kph - 5.4 sec
Acceleration - 0-400 meters - 13.9 sec
Coefficent of drag - 0.39
Ground Clearance - 150 mm
Engine model - SR20DET
Engine type - Turbocharged, in line 4 DOHC, 16 valves with intercooler
Displacement - 1998 cc
Max power output - 227/6400 ps/rpm
Max torque - 27.2/4800 kgm/rpm
Bore & stroke - 86 x 86 mm
Compression ratio - 8.3:1
Turbo - Garret TB2804 (T3/T25 combination -> Compressor = 60mm, 60 trim in .60A/R -> Turbine = 53mm, 79 trim in .86A/R)
Control system - Electronic port injection
Transmission - type 5-speed manual
1st - 3.285
2nd - 1.850
3rd - 1.272
4th - 0.954
5th - 0.740
Rev - 3.266
Final Gear Ratio - 4.125
Steering - Rack & Pinion, power assist with tilt
Suspension system - 4-wheel independent with front McPherson struts. Rear parallel links with struts
4-Wheel drive system - With viscous coupling, centre differential and viscous LSD
Brakes - Heavy-duty front ventilated disc brakes and rear disc brakes
ABS - A 4-sensor, 2-channel electronic anti-lock braking system is available
Tires - 195/55R14 82V radials
Wheels - 14-inch aluminium 14 x 6JJ
Total Number of GTiR's Produced
The total number of GTI-R units produced was under 15,000
(exact number is unconfirmed, but either ~11,500 or ~13,800)
Production was done in Japan and ran from August 1990 until November 1994.
The commonly quoted figure of 5000 (4500 RA + 500 RB)
applies to the first year of production only (90-91)
which Nissan had to fullfill under FIA regulations in order to enter as a manufacturer in the World Rally Championship.
There were 5 seperate periods of production:
000102 (08/90) - 005769 (04/91) 
020004 (06/91) - 021480 (09/91) 
051003 (10/91) - 053490 (07/92) 
100003 (08/92) - 102340 (07/93) 
150002 (08/93) - 151846 (11/94) 
(these figures have been extracted using the chassis-lookup feature of the Nissan FAST parts system)
The Japanese Club quotes slightly different numbers - but an explanation has not been able to be communicated:
000101 (02/90) - 005485 (04/91) 
020001 (05/91) - 020969 (09/91) 
051001 (10/91) - 053368 (07/92) 
100001 (08/92) - 102215 (07/93) 
150001 (08/93) - 150522 (08/94) 
THE DIFFERENT MODELS
There were only 2 versions of the GTI-R sold to the general public:
GTI-RA - (Alpha) aka RA / Road / Luxury = MODEL NUMBER: EBYNRVFN14xxxx
GTI-RB - (Beta) aka RB / Rally / Homologation = MODEL NUMBER: EBYNRRFN14xxxx
[model # is found on the VIN plate]
NISMO - there were several (total unknown - but at least 5) RB versions sold with special Nismo ID plates.
They sported many of the Nismo rally options (suspension, diffs, seats, roll cage, foot rests, etc),
and were probably built as promo cars, and then eventually sold to private buyers in the mid-late 90s.
GROUP A - The Group-A Rally Car was not sold in showrooms (used for the WRC by NME as their Works car).
SUNNY - This was the badge used for the European-delivered models. They have different model numbers.
Exact amounts are unknown, but several hundred RHD versions were sold in the UK,
and under 1000 LHD units were sold in Germany, Italy and France (other countries unconfirmed).
"DAKAR" - the name Dakar is sometimes used (mainly in UK) in reference to the RB,
but that name DOES NOT appear in any official texts or anywhere on the cars,
and the car was never entered in the famous rally by that name.
IF ANYONE CAN PROVIDE ANY INFO/EVIDENCE TO PROVE OTHERWISE PLEASE LET US KNOW.
"HKS" - Contrary to some links on the 'net - there was never an HKS version (or HKS promo car).
THE DIFFERENCES IN THE "RA"
Basically, there were 2 main series/versions/phases of RA (road) cars,
they can be identified by their chassis numbers:
BELOW RNN14-100000 (Early / Phase1)
ABOVE RNN14-100000 (Late / Phase2)
There are actually 4 variations (at each 50000 chassis interval),
but the exact details of the changes are unclear and they seem to be cross-over periods with bits from both:
These are the changes made to the Late models:
- body colour super white  replaced the early ivory/marble white [KJ7]
- body colour only available in black [KH3] or the above super white (no more grey [TJ1] or red [AJ4])
- umbrella holder removed (blank panel, rather than vent from the RB model)
- headrests changed to solid (from hollow/donut-style)
- interior fabric trim changed to the same as the SSS model (no longer specific for GTI-R)
- badge on front grill changed to "Nissan" (from the Prince "P")
- steering wheel changed to generic black Nissan logo debossed (instead of red GTI-R logo button)
- windscreen changed to monotone (no more upper blue section)
- roof lining changed to vinyl from twill (except for those that chose the sunroof option)
- main instrument cluster modification (logos changed to hidden unless lit, and ANTI-LOCK logo changed to ABS)
- the water pump model was changed
- a couple of supports were added (clutch pedal bracket and side door beams)
There were NO changes to the engine or exterior.|
There WAS a limited run of Turquoise Metallic [DL2] coloured examples - the unconfirmed rumour is that it was for a commemorative event in Japan (Emperor's Day?) - also unconfirmed is the number, some say 20, some 30, some 50, etc - there has never been any proof - but it is clear that they are by far the rarest of the colours...
THE DIFFERENCES IN THE "RB"
The homologation (RB) model was specifically built to be used for Group N rallying, and had all the luxury trimmings removed as standard.
Originally thought to be the difinitive spec - it is now clear that some of the luxury items were available as an option
(but mainly found in the later years):
- no colour-coded side mirrors (grey plastic - standard)
- no umbrella holder (a vent is there instead - standard)
- close ratio gearbox (standard)
- front lsd (standard, but other front diffs optional)
- steel wheels (standard)
- no rear wiper (optional)
- no air con (optional)
- no electric windows or mirrors (optional)
- interior from base-model pulsar (vinyl trim, basic seats, rubber gearstick boot - standard)
- exterior paint marble/ivory white (optional - but it seems most of the early ones are this colour)
There were also many Nismo Rally Options (as seen in the Best Motoring Special #13 video)
(see list below)
Nismo had a promo RB sporting all the Nismo options (see Gallery).
Autech sold some of the RB versions (Autech is a tuning company that sell complete upgraded cars).
There were factory options available throughout production:
- climate control (common)
- wind deflectors (common)
- plastic protectors (doors, handles, bumpers)
- heated seats (very rare)
- heated mirrors (rare)
- illuminated ignition ring
- rear parcel shelf speaker upgrade
There were also motorsport options:
- rear roll bar
- driving lights
- knee rests
- bumper protector
- foot rests (different from Nismo ones)
- strut braces (different from Nismo ones)
- rear diff cover (different from Nismo one)
There were also many Nismo options:
- strut braces
- steering wheel
- seats & belts
- underbody guards
NOTE ON NORMAL FACTORY OPTIONS:
It seems that many late models have more of these options than early models, which logic suggests is most likely due to the general rule that towards the end of production showrooms would do good deals on them.
FACTORY COLOUR CODES:
KH3 = Super Black (entire production)
AJ4 = Red (early models only)
TJ1 = Blue-Grey Graphite Pearl (early models only)
KJ7 = Ivory/Marble White (early models only)
531 = Super White (late models only)
DL2 = Turqoise Metallic (special commemorative only) [previously thought to be FM0]