The information provided in this thread may not be accurate or complete, thread is under construction, please reply or send pm if you have anything to add.

Mazda RX-7 FC3S

Dates of production:
Series 4: 1986-1988
Series 5:1989-1992

Production figures:
Series-4 = 86-88
86 = 72,760
87 = 52,204
88 = 34,592

Series-5 = 89-91
89 = 37,642
90 = 29,411
91 = 16,623
92 = 00,500 (commemorative convertibles)

Total = 243,732

Summary




The second generation RX-7 still known as the "Savanna RX-7" in Japan, featured a complete restyling reminiscent of the Porsche 928. Mazda's stylists, lead by Chief Project Engineer Akio Uchiyama, actually focused more on the Porsche 944 for their inspiration in designing the FC because the new car was being styled primarily for the American market, where the majority of first generation RX-7's had been sold. This strategy was chosen after Uchiyama and others on the design team spent time in the United States studying owners of earlier RX-7's and other sports cars popular in the American market. The Porsche 944 was selling particularly well at the time and provided clues as to what sports-car enthusiasts might find compelling in future RX-7 styling and equipment. Handling was much improved, with less of the oversteer tendencies of the FB. Steering was more precise, with rack and pinion steering replacing the old recirculating ball steering of the SA. Mazda also introduced Dynamic Tracking Suspension System (DTSS)in the 2nd generation RX-7. The revised independent rear suspension incorporated special toe control hubs which were capable of introducing a limited degree of passive rear steering under cornering loads. Mazda also introduced Auto Adjusting Suspension (AAS) in the 2nd generation RX-7. The system changed damping characteristics according to the road and driving conditions. The system compensated for camber changes and provided anti-dive and anti-squat effects.

Factory Specifications
Engine
Type: 2-rotor inline rotary with 6 port induction, intercooled turbo
Displacement: 1308cc
Compression ratio: 9.7:1, Turbo 90:1
Power: 160hp @ 7000rpm, Turbo 200hp @ 6500rpm
Torque: 140 lb-ft @ 4000rpm, Turbo 196 lb-ft @ 3500rpm
Fuel system: Multi-port electronic injection
Fuel capacity: 70L

Transmisson
Ratios:
5-speed 5-speed Turbo Automatic (coupe) Automatic (convertible)
1st: 3.475 3.483 2.841 2.841
2nd: 2.002 2.015 1.541 1.541
3rd: 1.366 1.391 1.000 1.000
4th: 1.000 1.000 0.720 0.720
5th: 0.697 0.719 ----- -----
Reverse: 3.493 3.288 2.400 2.400
Final: 4.100 4.100 3.909 4.100
Clutch: Single dry plate
Torque converter: Lockup type

Electric system
Battery : 12volt
Maintenance free 55amp/hour (cold areas: 65amp/hour)
Alternator: 80amp
Ignition system: Electronic, with four-electrode spark plugs and electronic spark advance

Chassis
Frame: Semi-monocoque
Front suspension: Independent, strut-type with coil springs and stabilizer bar
Rear suspension: Independent, semi-trailing type with coil springs and stabilizer bar; Dynamic Tracking System with Triaxial Floating Hubs
Adjustable Suspension: Automatic Adjusting Suspension (AAS): GXL
Steering: Power assited rack and pinion type
Engine-rpm sensing varible assist: GTU
Vechile-speed sensing varible assit: GXL, TURBO, CONVERTABLE
Steering wheel turns, lock to lock: 2.7
Turning circle diameter ( curb to curb) 9.81m
Brakes: Power assisted, with dual hydraulic circuits
2490mm ventillated front discs, 2620mm solid rear discs: GTU
2770mm ventillated front discs with four piston alloy calipers,
2720mm ventillated rear discs: GXL, Convertible, TURBO

Curb weight: 1358Kgs (Turbo)

Dimensions
Wheelbase: 2477mm
Lenght: 4315mm
Width: 1689mm
Height: 1265mm
Track front/rear: 1450mm/1440mm
Headroom: 945mm
Headroom w/sunroof: 935mm
Legroom: 1110mm
Shoulder room: 1341mm

Factory Colours and codes
Colour/ Code
Series 4:
Photography by Allen Gibbs

Satin Gold Metallic Clearcoat 1A
Royal Marron Metallic Clearcoat 3A
Sapphire Blue Metallic Clearcoat 5A
Tornado Silver Metallic Clearcoat K8
Custom Silver Metallic Clearcoat V9
Sunbeam Silver Metallic Clearcoat K3
Dover White WU
Sunrise Red RH
Nobel White WY
Crystal white UC

Series 5:

Satin gold metallic clearcoat 1A
Claret mica metallic clearcoat 2H
Sapphire Blue Metallic Clearcoat 5A
Arctic Silver Metallic Clearcoat J5
Tornado Silver Metallic Clearcoat K8
Winning silver metallic clearcoat 1F
Harbor blue metallic clearcoat 5D
Brilliant black clearcoat PZ
Shade green GU
Blaze red SQ
Noble white WY
Crystal white UC



Factory Produced Models


Japanese Market
G is the base pack with wind up windows and manual steering rack and no air con. But you do get am/fm radio they come with steel rims and no rubber strips down the side of the doors.

GL and GX is like GT-R with the basics like air con and power windows.

GXL is a mix of options between GT-X and GT-limited (various combos of options)

GXS is an optioned sports model and heaps of them about, they came with the infini rear bucket tubs.

GT-R has no A/C or electric windows and power steer and manual damp adgust coilovers KYB I believe, but No electric mirrors sunroof, leather, climate control or LSD

GT-X semi up market model, has electric damp adjust sport/normal mode coilovers, LSD and optional sunroof, electric mirrors and all the other luxuries.

GT-limited has all the same extras and options as GT-X but also has optional leather interior and climate control.

Convertible- Mazda introduced a convertible version of the RX7 in 1988 with normally aspirated and turbocharged engines.

The convertible featured a removable rigid section over the passengers and a folding textile rear section with heatable rear glass window. Power operated, lowering the top required unlatching two header catches, power lower the top halfway, exiting the car, folding down the rigid section manually, and then further power-lowering the top. Mazda introduced with the convertible the first integral windblocker, a rigid panel that folded up from behind the passenger seats to block unwanted drafts from reaching the passengers — thereby extending the driving season for the car in open mode. The convertible also featured optional headrest mounted audio speakers and a folding vinyl snap-fastened tonneau cover. The convertible assembly was precisely engineered and manufactured, and dropped into the ready body assembly as a complete unit — a first in convertible production.

In the spring of 1992, the coupe RX-7 replacement, the third generation RX-7 (FD3S) was released, however Mazda continued production of the FC3C Convertible until 12/92 as a 92 model year. The 92 Convertible was identical to the 91 versions except that a tan interior seating and door surface color option was added to the line up.



Infini-



3 model were produced being INFINI II, III, IV. IV being the rarest of them all.
(pronounced on'-fin-ee).

Although Mazda had produced earlier versions of the Infini, the IV was the first to bump up power and the suspension.

Stripped of all Savanna and RX-7 identification, this was the last limited edition ultra high performance version of the 2nd-generation RX-7. A factory hot rod, the Infini IV was lightened (to 2770 lb.), by stripping out the extras such as a sun roof, and using lighter parts including lightweight alloy bonnet and front fenders, perforated suede like material racing style seats, a smaller brake master cylinder, reducing the noise dampening material and using the 1986-1987 Sport/GS model's light weight carpet. And a red strut tower brace and a Momo 3 spoke steering wheel and Infini logo horn button.

With a revised suspension (shocks 25% stiffer, springs 10% stiffer and lowered 1") Special Pirelli designed P-Zero tires, ultra lightweight 16 inch BBS wheels and a bright red front strut brace, the handling improved to a skidpad of .91 Gs. The Infini IV (as with most 91 models) also came with the tighter steering rack from the 89-90 North American GTUs model and its engine speed sensing power steering. Molded knee Pads at the driver's door side and center console were added to help brace the driver's legs while cornering, while a "dead pedal" bar ran the length of the passengers floor.

Similar again to the US spec 1989 and 1990 GTUs the Infini IV came with the 4.3 rear end final gear (but also used a new Torsen Limited Slip Differential), and the options kept minimal with air conditioning, Infini embroidered floor mats, and a AM/FM radio the few options available (however it did come standard with a rear window wiper and power windows). Power was bumped to 215 HP (JIS), largely by changing the exhaust to a free flowing design. The Infini IV, also came with the Bronze tinted glass found in the US spec 10th Anniversary edition, and was available in one of two custom black/green metallic paint colors. Of the 600 made, the first 300 cars built on limited production runs between June - Dec 1990 were painted Mazda paint code GU (Shade Green) while the last 300 cars built starting Jan 1991 through February 1991 were paint code VQ. Of these last 300, 20 of them where sent to MazdaSpeed for the MazdaSpeed Package which only did minor cosmetic changes like MazdaSpeed embroidered seats, MazdaSpeed steering wheel and shift knob.


0-60 performance was reported at 6.5 seconds and the quarter mile time dropped to 14.9 seconds, with Infini specific brake pads helping make an impressively matching braking force of 60-0 in 141 ft (8 feet less than the standard RX-7 Turbo) despite the ABS being deleted off of the car at time of production.

View the brochures-

1986
http://www.mazdamark.com/86Bro23.jpg
1987
http://www.aaroncake.net/RX-7/brochure/29.jpg
1987.5
http://www.mazdamark.com/FC87_5_Brochure.jpg
1988
http://www.mazdamark.com/88bro28a.jpg
http://www.mazdamark.com/88bro29a.jpg
1989
http://www.mazdamark.com/89bro26.jpg
the GTUs
http://www.mazdamark.com/GTUs.jpg
1990
http://www.mazdamark.com/90bro21.jpg
http://www.mazdamark.com/90RX7brob.jpg
1991
http://www.mazdamark.com/FC91Brochure.jpg
http://www.mazdamark.com/91bro24.jpg


Austrailian Market:
Turbo II- ABS, sunroof and cruise control standard, headlight washer jets(option), LSD (option).
Sports- NON-TURBO.Australian Motors Mazda released a limited run of 250 'Sports' model Series 4 RX-7's; each with no power steering, power windows or rear wiper as an attempt to reduce the weight of the car.


Series 4 and Series 5 Difference's




Interior:



The Dash - There is a very slight difference between S4 and S5 dashes in the way they fit to the existing fittings, these can be adjusted to fit however for fairly cheaply.
Series 5 Rx7's have the full circle water temp, boost, oil and fuel gauges; s4's have the half moon style.

Dash Gauge Cluster - If you want to upgrade say for example from a S4 cluster to a S5 cluster it is possible but you will need to change the loom or adjust the wiring in order to get all gauges to work correctly. (May Not be required for some aftermarket ECU's)

Idiot Cluster - The idiot cluster if it needs to be updated will not fit correctly and is quite expensive to fit.

Front Seats - are different shape but rails are the same.
- Cruise control including control unit and switch (not sure if interchangeable)
- All the switches and knobs on the cluster surround are slightly different as well as the cluster surround itself.(interchangeable)
-The radio heater surround and gear stick surround different.(interchangeable)
- Door trims and window switches (interchangeable) - Inner door skins (trim) are different on s5, as speakers are mounted.
- Logicon units have different symbols
- Idiot light lens is at a different angle on OZ spec s4s to all other models (except some us models)
- Bezel for idiot lens changes to suit above
- Shift knob redesign along with steering and facias
- Stereo design advances in s5-some have digital display for equaliser
- Interior materials differ between series and model
- Rear speaker covers differ between series/model

Exterior:

- Different and colour coded strips that run around the car, trims around the car Mouldings (interchangeable)
- High brake light at the rear
- Tail lights, of course (interchangeable with slight mods)
- Front and rear bar - s4-5 front bar indicators are different sizes
- Factory bodykit differences (Series 5 have side skirts, etc)
- Rear wings are different
- On an FC Rx7 from an s4 non-turbo to an s5 turbo the front bar supports (front and rear reos/reinforcements) are identical. If your after market body kit doesn’t fit it could be the kit it self, previous damage to the car or just the person trying to fit it.
- Front reinforcement bar for s5 has provisions for mounting fog lamp assemblies
- s5 Aus delivery has different side indicators imports don’t (interchangeable with slight mods)
- s5 guards have bigger lip to bolt on side skirts (interchangeable)
- s5 have a rear hatch cover and light mounted in the boot (interchangeable with slight mods)
- Central high mount stop light is optional on both s4 and s5
- same as above for 'no rear wiper' model
- s4 bonnets are mild steel, some s5 bonnets are aluminium and some mild steel
- rims differ between series/model
- 88 model Aus spec s4 has this middle brake light as well (the one near the key hole for the boot)

Mechanical:

Series 4 NA: 146 HP @ 6500 RPM w/ 138 Ft/lb @ 3500 RPM
Series 4 Turbo: 182 HP @ 6500 RPM w/ 183 Ft/lb @ 3500 RPM

Series 5 NA: 160 HP @ 7000 RPM w/ 140 Ft/lb @ 4000 RPM
Series 5 Turbo: 201 HP @ 6500 RPM w/ 196 Ft/lb @ 3500 RPM

Engine:

Turbo waste gate/manifold differ between series, series 5 turbine housing is larger and has two waste gate holes instead of 1 on the s4
s4 has mechanical oil metering pump and s5 has electric pump with stepper motor
Intercooler apparently s5 has a couple of extra rows of cores? (interchangeable)
Radiator and water pump are different (interchangeable with slight mods)

Driveline:

Diff:

Although they may seem similar, there are some slight differences between the factory Differentials. Both are LSD with the same spines.

Series 4: clutch-type LSD's
Series 5: viscous-type LSD's

Ratios:

S4 Manual: 4.1
S4 Auto: 3.909


S5 Manual: 4.1
S5 NA Manual: 4.1 (4.3 LSD)


JAPSPEC SER 5 turbo FC3C 90 build--convertible-- has an open diff as standard not an LSD.
Gear box different ratios between the two (interchangeable)

Suspension/Brakes:

- ABS standard on Aus delivery s5 but not on all imports.
- Apparently sway bar ends are different?(interchangeable)
- The brake and clutch master cylinder between S4 and S5 are the same, however the non-abs model are different to the abs equipped model and are NOT INTERCHANGIBLE unless you have both matching booster and master cyclinder along with matching lines (or modify existing brake lines)
- steering rack ratios differ
- manual steering rack + windows and mirrors only released on early base model s4s

Electrics:

- Alternators are different betwwen s4 and s5
- ECU and wiring loom not interchangeable including air flow meter, injectors and various other sensors.(NOT interchangeable)

Other:

- VIN Differences

It's possible to find out more information about the FC series you have or are looking to buy by cross-referencing the VIN number with the Make and Model plate to make sure it's correct.
Take a look at the 10th digit in the VIN and reference the info below.

1986: G
1987: H
1988: J
1989: K
1990: L
1991: M

The 8th digit of the VIN is for engine type

1: N/A Model
2: Turbo Model

You can tell the difference between an Aus delivered and a Jap import by looking at the chassis code.

Aus Deliver: FC10
Jap Import: FC3S

Join the FC3S VIN register here- viewtopic.php?f=21&t=154965

Links
Factory service manuals- http://www.cochran-racing.com/FSM/s5/index.html
2nd gen FC RX-7 FAQ's- http://www.mazdaforum.com/m_13028/tm.htm
FC3S owners- viewtopic.php?f=21&t=15851
FC3S Video thread- viewtopic.php?f=31&t=186383
FC3S Picture Thread- viewtopic.php?f=31&t=149462

the obvious engine clues to what FC short block is what
( own pics )
-------------------
the block housings --

externally, all FC type 6 port housings will have a " multi chamber port insert " baffle in the exhaust port
( sorry no pics )

as a comparison 82- 85 RESI motor six ports have different water seal location
( in housing, not plate, AKA rx4 )
smaller, conventional exhausts
different font, and the nsu patent scribe stuff
and oil injector locations very close to the inlet manifold
( s4 on is further towards top )



s4 has just the spark plug holes with collars , nothing more
( these are all s4 housings in pic )
turbo ones, have a conventional exhaust baffle , conventional spark location , and are cast with "n318" onto the top
the 2nd housing in from left is an NA one
note the housing leg differences
and that the leading spark hole is actually different to others, and is in same location as factory PP housing
( this NA housing also has a full sized font boss and doesn't have "N318" cast onto the top )

however i have yet to see an N318 with the full sized boss casting



s5 turbo and not have a threaded hole above the trailing plugs for revised knock sensor location
- and same spark plug locations , these are N370, s5 turbo
- and more usually, full sized font casting, evident in pics ( there is exceptions )




most visible on the red s4 housing, and not on those s5 ones next to it is the differences in casting on top of the housing
- here the s4 turbo housings have " N318 " bossed onto them








NEARLY all s4 motor housing will have the mazda logo casting large enough for the 13b and mazda fonts only


look closely on back of the ute,,, first at left is an odd s5 housing with small font !!!
i believe this is a housing originally intended for an 87 HC luce/ cosmo single turbo
- these seem to have been " crossover " motors with run out selections of s4 manifolds and turbos and some plates with s5 rotors and housings




here is another HC Luce/ cosmo , as mentioned above
this one built with s4 rear and s5 front plates, and odd legged housings , s5 weights and rotors
and the short block on knockdown appears completely factory assembly
( though the whole motor in that pic has early 12a timing cover, modded sump and a carb adapter as it was retrofitted in to an early rx7 )

the motor plates -




close up of the 87/88 luce/ cosmo motor above, s4 rear plate, s5 front plate , s5 knock holes, the housings have odd legs, s5 rotors
( these housings have the large font, but these engines show not a lot of consistency )
the picture is indicating lack of diagonal wedge support around rear oil dowel , an s4 plate indication
s5 would have a visible extra wedge of casting across the oil dowel



up top, with water grooves, NA s4 plates, note ACV blank plates on top !
the left is stock, right, somebodies ( not mine ) attempt at mild !
the others are earlier plates from a RESI and a 12at



why would you bother building up the 6 port primary plate when the turbo plates start as good as the other will get ?
( the secondary plate behind is mild extend ported )




if you see that nylon support for the oil passage O ring, its an s5 front plate



6 port end plate ( the runner here is modified and merged )
s4 and s5 are the same porting, again with running improvement to the s5 rear dowel casting, and front oil O ring support boss



standard port s5 turbo plates, s4 is same ports
note the wedge under the oil filter pedestal across the dowel casting

--------------

the rotors-



s4 NA= 9.4: 1
s4 turbo= 8.5:1
s5 NA= 9.7: 1
s5 turbo= 9.0: 1

all FC rotors where built with 2 mm 3 piece apex seals , and 0.7 mm side seals with key hole corner seals
turbo and non turbo rotors of the same generation use same counter weights
( s4 is s4 , and s5 is s5 )







s4 turbo rotors usually have a small "mark" dent pressed into the bath recess
the casting work in the bath recess signifies s4 and earlier rotors


s5 rotors feature the finishing machine work, apex tip to apex tip
- machined right through the rotor bath, s4 not






EDIT
thank image crap for the pictures that do work yet sometimes won't load
all pictures loaded and tested OK on original submit

the water pumps
knowing how popular a retrofit this engine is
i will include comparison to the earlier 12a / 13b NA water pumps and also that timing cover
where applicable for water pumps

generally speaking -
things had running changes, mid production, and also NA and auto models differed a little in configs
FC pumps types are usually easiest identified by the housing to thermostat neck bolt count
earlier 2 bolt type pump with housing are generally called s4 type
though, in fact, the three bolt type featured in later s4 cars, just before advent to s5
( with the injectors and loom )
the late 87 and early 88 FC water pumps could bring some odd mix matches of radiators and overflow bottles !

the s4 and s5 non turbo water pumps do not have an added entry for turbo water return at the water pump inlet ( )
turbo and non turbo all have ( like some early 80's 12a and 13b ) an outlet ( inlet ! ) facing rearward from the housing
- this routes via a few devices and originates in the motor block, top of rear plate

auto versions often have added thermo switches in the rear of the pump housing alongside with the EFI water temp sender
early s4 NA water pumps have a sort for bigger pulley !
FC water pumps have different ID diameters on the pulley boss to 12a also

all FC water pumps have a long bolt for the ALT bracket, that taps into front plates
- this can sometimes catch out unwary people mixing and matching 12a and FC pumps

EG
if i was chucking any FC pump onto a 12a front engine plate
some re-tapping of the pump and its housing ( not the plate ! )
is required for a short wide bolt to hold the alt bracket, and block the hole also

in vichy france, that would mean a 12a pump and housing onto FC front plate
in that situ, a good blob of silicon will block the offending stud hole

------


early FC , 1986 and 1987 uses a two bolt thermostat cover and conventional 12a type thermostat ( re rated )
most have a filler point there, and a remote fitting with true overflow cap that heads to the bottle
some have a solid neck, and a cap on top of radiator instead ( 87, 88 )
all those with 2 bolt thermo covers ( 86, 87 , early 88 ) use a different water pump to those with a 3 bolt cover ( 88- 92 )

the three bolt cover is usually plastic, and doesn't have a filler point there, instead that car has a different radiator with a filler pipe added to the rad

the 3 bolt cover, later FC pump will not fit onto the early water pump housing and vichy versa
you must always move the water pump housings with it to suit
unfortunately, almost universally, its this pump that will be parts listed as suitable for s4, and isnt !
check , double check, assume the listing at the shop is wrong !!!!!!
the 3 bolt cover unit also needs a different thermostat
( and here trident and co's list the s4 unit as a s5 one !!!!! )
the s5 ( late s4 ) 3 hole thermostat cover thermostat needs a rubber edge ring to suit it properly
s5 pumps use a different pulley ID to s4 !

s4 and s5 pump swap arounds ( and the 12a pump and its housing ) quite often clash with the incorrect timing cover
early s4 and 12a prove instantly friendly
and s5 to anything a bitch



thats a silver 12a one ( with a hard to find s4 two bolt non filler neck pipe fitted )
and a red s4 NA water pump unit




a different red s5 pump onto a 12a timing cover ( pictured )
( or an s4 timing cover )
requires the bottom bolt and the casting on the s5 housing and pump to be shaped on the belt sander


( also sometimes there is a casting nub on some timing covers that needs a chisel/ grind )
where there is will , there is a way, and all will fit about with massages


that is s5 pump on 12a timing cover



FC units on the right
( 3 bolt holes for coolant housing to front plate )
FC units are distinguished by being alum, and that extra bolt hole in the coolant housing into front plate
s4T with the extra turbo return nipple on the pump inlet
note some have thermo switch, some have thermo sensor, some have both
some have coolant return pipe

FC units, GSL-SE ( RESI 6 port ) , and 12aT coolant housing units will feature an EFI coolant sensor
some 12a/13b coolant housings will have a water return from sundry devices at the rear like FC does
some housings of all types will have a thermo switch also
( and on off device )
typically aircon and auto cars, and s3 rx7



NA s4 ( top)
turbo s4 ( bottom )

the injectors
-------------


- all NA models are 4 x 460 cc
- all FC turbo models are 4 x 550 cc

always check the plug shape and notch location suit your loom , and verify the PART number
when these are old, red, purple and tan as the original colour can become indistinguishable
- nearly all fade to brown/tan !!!


early ( zenki ) FC- NA and turbo, usually 86 and till late 87 have peak hold injectors
- and a ballast resister block incorporated in the loom to limit ECU heat
these injectors are referred to as low ohm injectors

86-87 13B NT 195500-1350 low ohms square plug center notch 460cc red
86-87 13B T 195500-1370 low ohms square plug center notch 550cc tan


come just before the s5 , this was revised to be saturated type injectors
( cheaper to make, but slower to react, and slower to shut accurately )
the loom resister is deleted OEM at this point !
BEWARE that when mixing and matching the injectors with a stock ECU
VERY IMPORTANT

88 13B NT 195500-1350 high ohms square plug offset notch 460cc purple
88 13B T 195500-1370 high ohms square plug offset notch 550cc purple


come the full ( kouki ) s5 model the injectors are still saturated, high resistance style
- but now come with an oval plug

89-91 13B NT 195500-2010 high ohms oval plug center notch 460cc red
89-91 13B T 195500-2020 high ohms oval plug center notch 550cc purple




s4 turbo ones, obviously ( tan that now looks purple !!! )
some supra guys chase for these as they are rail fit and suit their ECU



notice the oval ones
these are the two variations of the high ohm turbo ones
late s4 ( square ) and s5 ( oval ) , both red !



bloody NA ones trying to sneak in with the turbo party
without checking the notch or part number, most are caught thinking they are late s4T 550cc high ohms
( they are in fact 460 cc lows !!! )
- see how badly everything fades -
one mans over phone description of the colour wont help you! get the PART number !



s4 fuels rails, easy to pick, and desirable
the NA secondary rail is at the top
- s4 rails are alum, and used threaded fittings, easily changed, easily machined bigger
s5 units are steel, and the regulator integral

the fuel flow is counter current on some s4 turbo cars, co-current on others
(s4 NA and s5T all are co-current )
the s4T reg and the dampener are interchangeable , as demonstrated

Another colour option to add that was available in Europe and Japan:

Series 5-
Shadow silver metallic clearcoat 3G

the turbos--


where do i start? i am completely unfamiliar to the FC turbo !
LOL

all are Hitachi HT-18-2S, but often referred to as HT-18S
s4 types -

early s4 86/87 HT18S-2SC N31813700C ( small banjos, deep recess cartridge lip and volute )
later s4 87/88 and vert HT18S-2SE N34413700
Luce HT18S-2SD N33713700A

s5 types -

s5 HT18S-2SF N37013700
later s5 and vert HT18S-2SG N37813700

to be honest, you cant pick them from another by eye, just s4 early/ late and s5

- i have only ever seen one change in rear wheel/ shaft and compressor profile turbo to turbo
( i suspect it was a jap rework as the nut was reverse thread !! = signature from 1 jap turbo manufacturer )

these HT-18s-2s have a water cooled core
which is mazda division 5/ hitachi patent evolution developed from the non water cooled Garrett T03/ T04B parts bin
( journal size/ parts , thrust bearing, backing plate, spider washer and carbon seal )
the compressor and exhaust wheels and volute profiles are Hitachi unique, specially for Mazda
hence, people find that Garrett T3/T4 series parts and kits interchange to some extent

s5 and s4 differ in rear volute only, s5 being split pulse entry from the OEM manifold , with twin waste-gate flap the result
s4 feature the scroll can and flap
speaking directly on the s4 twin scroll theory -


which down low closes one half of the asymmetric entry paired openings
generally, the s4 and s5 rear turbine volutes and waste-gate can can interchange
though very early s4 have small water banjo fittings, and a deeper cartridge step for the turbine volute
this can be engineered around !



s4 block has a "twin scroll" pneumatic gate as well as the similar looking waste-gate actuator
( and a birds nest to suit )
that's the ugly big can attached to the s4 turbo manifold on the bench


the s5 turbo ( left ) is a conventional enough square base on the turbine volute
s5 block has a boost control solenoid on the filler pipe ( of all places ! )
the s4 turbo foot ( right ) is asymmetric in pattern



the s5 has an obviously larger rear plate than the s4 units on the right



and that's why, twin waste-gate flap in the s5
i have overlaid the s4 turbo over the top of the s5 volute

infini IV's never came with aluminium guards, and a/c was standard on them

Got anything to support that? In one of my RX-7 books it states that air con was an option.

the book you have will no doubt be an american print, i have seen this incorrect info plastered all over the web, i have owned 4 of them and every one has steel guards part numbers for infini chassis are the same as series 5 chassis, japanese brochures i have state factory a/c and everyone ive owned or ever seen have had a/c. there are a few other differances that you havnt mentioned but nothing really substantial, and i believe all IV's had infini logo mats but cant confirm for sure

i have an Australian delivered series 5 june 89, can anyone tell me if there are any external defferences to look for between a factory lsd and open wheel diff. not sure if it's an lsd or not?

i forgot to add it's a turbo II

hey guys
how much do the s4 rx7 non turbo weigh?
from jordan

Weight (Approx.) Series 4: 1224 kg (13B EFI), 1270 kg (13B Turbo)

Weight (Approx.) Series 5: 1247 kg (13B EFI), 1315 kg (13B Turbo)

INFO from http://www.mazdarotary.net/fc_rx7.htm

hi guys, just a few questions, is a s4 n/a tailshaft the same as s4 turbo tailshaft?

also i have bought a s4 turbo rolling sell with engine bay stripped and loom cut of at firewall, is it easy enough to put s5 turbo engine and gearbox in it, or stick with s4 turbo engine? i read on here computer etc not interchangeable, however i am not wanting a aftermarket computer

NA tailshaft different input spline,, and different PCD to diff flange

thank you for the informatin bumpstart

hey guys trying to work out if my shell is na or turbo on the import plate it has 7a8c1030794117309 is that the right vin?
any help would be apreciated

serial number doesnt like right read it directly off the firewall or vin plate, dont go by the import plate.

should start with JDMFC3S........
or JDM1.....
or JDMZ......

The 8th digit of the VIN is for engine type

1: N/A Model
2: Turbo Model

i didnt think that was right but wasnt sure will have a look tomorow thanx

Massive nitpick here:

You write infini had 10% stiffer springs and lowered one inch - i have a set of infini coilovers and the springs are exactly the same (measured) and no lower - however they could be replacement springs? Not sure.