The year was 1991. Nissan had
released its 300ZX twin-turbo. Honda's NSX was one of the only cars in
decades to put fear into the primarily European competition. Mitsubishi's AWD
3000GT Twin Turbo had more technological wizardry than ever seen in almost
Mazda's flagship sports car,
the RX-7 had been around since 1978. A replacement was in the workings...
The story behind the third-generation Mazda RX-7 (FD3S), is one of dedication
and attention to detail. The project began in 1986 -- just after the release
of the second generation (FC3S) RX-7, and at a time when a Japanese sports
car revival was just over the horizon.
Takaharu Kobayakawa, the
program manager on the project, was determined that the changeover to the new
model was not a Zevolution.
It was a term he used to describe the competitor, Nissan's, Z-cars, which got
progressively larger and heavier with each generation. As its competitors
gained gadgets and driving aids, such as self-adjustable spoilers, rear-wheel
steering, traction control, and all-wheel drive, Kobayakawa felt they were
losing sight of the original vision. The RX-7 was decided to be a pure,
back-to-the-basics sports car. (Kevin McCauley)
The styling of the new car would
be an intensely personal and emotional decision for Mazda, as the car was to
symbolize Mazda and the rotary engine to the rest of the world. Four different
design studios around the world were consulted to come up with the design
proposals. In June, 1987, the two best sketches were chosen from each studio.
Full-size rendering and 1/5 scale models were created for each of the designs.
Two particular concepts won out in the evaluation meeting in September of that
year, one from Mazda in Irvine California (MRA) and the other from Mazda
Hiroshima (MC). The MRA model was a traditional long-hood / short-deck styled
concept that emphasized the engine placement and highlighted on the rotary's
past. The MC styled concept had a more futuristic short-hood, long tail theme,
and was found to be aerodynamically superior. Despite this, the MRA design was
picked, and together the two teams refined the model and implemented aerodynamic
elements from the MC design. The choice was made by Mazda only, without outside
assistance. Early in the development, stylists thought that to accurately
assess the visual impact of a sports car, it must be demonstrated while moving.
The car was fitted with a one-cylinder lawnmower engine in the trunk! About
halfway through the development in 1988, the Japanese government lifted a
small-car tax that previously applied to vehicles over 1.7-meters in width, and
with displacements over 2.0 liters. Designed to fit within that guideline, the
decision was made to widen the car. This allowed for wider, 225mm series tires
and 8" wide wheels, which improved the look of the car and the handling.
1) "Aero-Wave Roof" - a
double-bubble design that improves aerodynamics as well as looks.
2) Rotor shape in grill
3). Pop-up headlights - these
were an oversight- the car's low front bumper made the use of pop-up lights
Choosing the interior design
was easier- the MC's design won immediately over MRA's more wild, curvy
Handling was another crucial
issue in during the design of the 3rd-generation RX-7. In the basic design
of the layout, the designers followed these criteria:
1) All suspension
arms/links should be in line with the path of each input force or load,
2) A suspension functions
best when it is mounted on a secure base. The sturdy fabricated steel front
and rear sub frames are therefore rightly bolted to the body shell.
3) The body shell must
possess outstanding rigidity. It should also be light-weight, a key factor
in improving the car's power-to-weight-ration.
4) Unsprung weight must be
reduced as much as possible.
The suspension components, a
double-wishbone system, are all made out of a squeeze-cast aluminum alloy
and attached to the frame with the use of variable slide rubber bushings,
for a more precise road feel and sharper cornering. The engine is located
behind the front axle (front-mid-engined), giving it neutral steering and an
unprecedented 50/50 weight distribution. The
first used on the MX-5 Miata, is a cross-reinforced brace that connects the
engine and transmission with the Torson (torque-sensing) Limited-Slip
differential in the rear. It strengthens the frame and reduces flex, as
well as reinforcing the driveshaft to eliminate hop, snatch, and shudder
during acceleration. The brakes used are four wheel-ventilated lightweight
11.6" discs with four-piston calipers, assisted by standard ABS.
Lightweight 13.5 lb five spoke 16"-wheels aid brake cooling and reduce
No less hard work and effort
went into the new RX-7's engine. Koyakabawa and his design team were given
the option of using any engine that he felt best suited the car-- he chose
the rotary. The choice was made not only for its sentimental value, but it
also made sense in a purpose built- sports car. It was lighter in weight,
smaller in size, allowed to be positioned lower for a better center of
gravity and featured a better specific horsepower ratio than any
engine of the time. It was also chosen for its simplicity; a normal rotary
engine has just 3 moving parts: two rotors and an eccentric shaft. Many
people think the engine designed for this car was the first to utilize a
sequential twin-turbo system. The 13B-REW engine was actually the second
vehicle to utilize a sequential twin-turbo operation system-- it was first
developed for the Mazda Cosmo 3-Rotor Coupe. The system operates off one
turbo during lower RPM's (after 2,000 RPM) and the secondary turbo spools up
after the engine reaches the 5,000 RPM level. Mazda encountered many
problems along the development road with the sequential turbo operations,
and there were many doubts that a system used to increase efficiency on a
grand touring coupe would work on a pure sports car. If the secondary turbo
was not spinning at a high speed when it was brought in, the whole system
"staggers", temporarily failing to produce enough torque which is essential
for a smooth change over. Mazda's engineers attacked the problem, and
solved the problem by feeding exhaust gas from the first turbo to the
secondary turbocharger to get it spinning before the transition is made, in
"pre-operation" mode. The tiny 1.3 liter (two 654cc displacing rotors)
power plant put out an incredible 255-hp, and 217 lbs/ft of torque, with the
help of twin Hitachi HT12 turbos.
In 1993, the R1 was the
"purest of the pure". A limited-edition, racetrack oriented, car,. the R1
was only available in Vintage Red, Brilliant Black, and the rarest --
Competition Yellow Mica. Features exclusive to this model were dual oil
coolers, standard front and rear spoilers, functional brake cooling ducts,
stiffer shock absorbers, Pirelli Z-rated rubber and synthetic suede seating
that reduced driver movement during high-G turning or braking.
The R1 was short-lived,
replaced in 1994 by the R2. Only a few improvements were made, most
affected the cooling system and eliminated some problematic hoses that had
been the reason for several recalls. Silver Stone Metallic replaced
Competition Yellow Mica on the color list, although both had disappeared by
The Touring Edition / PEP
Offered in America from 1993
through 1995, the Touring (later named PEP for Popular Equipment Package)
was the less performance-oriented alternative to the R1/R2. With leather,
sunroof, Bose audio system, and available 4-speed automatic transmission,
among other things, it suffered a severe weight penalty. In Japan, this
model was called the Touring X, and offered exclusively with the automatic.
Launched as an early '93 model, the third-generation RX-7 adopted a back-to
basics approach that was reminiscent of the original 1978-85 model. The
convertible and the closed 2+2 coupe were gone, leaving a lighter, more potent
hatchback coupe with fresh styling. The rear-wheel-drive layout and 1.3-liter
rotary engine were retained from the second generation, but twin turbochargers
boosted horsepower to 255. Either a 5-speed manual or 4-speed automatic
transmission could be installed. The RX 7's wheelbase was little-changed, but
overall length shrunk by 1.4 inches. The car was 2.4 inches wider and 1.4 inches
lower than before. Base curb weight dropped by some 190 pounds, compared to the
old Turbo. A driver's airbag, all-disc antilock braking, and limited-slip
differential were standard. The performance-minded R-1 option added dual oil
coolers and body spoilers, but was not available with the luxury-oriented
Touring Package. That option group included leather seats, a power sunroof, Bose
speakers, and cruise controls in the steering-wheel hub. (Information straight from
1994:Improvements this year included a new
"one-touch" feature for the driver's window, plus map pockets. Dual airbags were
installed, and a softer suspension setting aimed to reduce ride harshness over
bumps--especially in the base and Touring editions. Dashboards were revised
slightly. A new option group put popular features into a single package. Three
major option groups were offered: Luxury-oriented Touring (now with a power
steel sunroof rather than glass); Performance (now called R-2); and Popular
Equipment (sunroof, leather, and a rear cargo cover).
1995:Not many changes were evident for 1995, as
the RX-7 began to fade out of Mazda's lineup, a victim of sluggish sales. The
car's standard air conditioning unit switches to CFC-free refrigerant. The
Touring Package was dropped, but leather seats, a cargo cover, and a power steel
sunroof remained available in the optional Popular Equipment Group. Red leather
upholstery no longer was offered. An R-2 performance package also remained
available, featuring a firmer suspension, dual oil coolers, rear spoiler, front
air dam, and Z-rated tires.
Mazda RX-7 2-door coupe
Overall Length, in.
Overall Width, in.
Overall Height, in.
Curb Weight, lbs.
Cargo Volume, cu. ft.
Standard Payload, lbs.
Fuel Capacity, gals.
Front Head Room, in.
Max. Front Leg Room, in.M
Rear Head Room, in.M
Min. Rear Leg Room, in.
Size liters/cu. in.
Turbocharged 2-rotor Wankel
1.3 / 81
5-speed manual: 4-speed automatic:
Information courtesy of
Mechanical Standard Features
- 2-rotor inline rotary engine with sequential twin
air-to-air intercooler, and electronic fuel
- Engine oil cooler
- 5-speed manual transmission with overdrive
- Power Plant Frame (PPF)
- Torsen torque-sensing limited-slip differential
- Fully independent double-wishbone suspension with rear
- Rack-and-pinion steering with engine-rpm-sensing variable
- Power-assisted 4-wheel ventilated disc brakes with aluminum
calipers and ducted backing plates
- Anti-lock Brake System (ABS)
Exterior Standard Features
- 16-inch aluminum alloy wheels
- Dual aerodynamic body-color power mirrors
- Tinted glass
- Retractable halogen headlights
- Lightweight aluminum hood
Interior Standard Features
- Highback bucket seats with seatback recliners
- Sport cloth upholstery
- Dual storage compartments behind seats
- Power windows and door locks
- Remote liftgate and fuel door releases
- 9000-rpm tachometer with 8000-rpm* redline
- 180-mph speedometer
- Gauges for oil pressure and engine coolant temperature
- Leather-wrapped steering wheel, handbrake grip, and
- Cruise-control with steering-wheel-mounted controls (n/a
- Driver's side air bag Supplemental Restraint System (SRS)
- Drilled aluminum clutch and brake pedals (manual trans.
- Anti-theft alarm system
- Heater/defroster with 4-speed blower and side-window
- Air Conditioning
- AM/FM/cassette stereo sound with five speakers and
automatic power antenna
* 7000 rpm redline with automatic transmission
I want to buy a 3rd Gen RX-7. What should I know?
There have been three recall notices put out on the 3rd
two pertaining to engine fires, and one concerning brake
You will want to make sure that the car in question has had
done. If they have not been performed, you will want to
take the car to a
Mazda dealership where they will be performed free of charge.
If you don't
know whether the recalls have been applied to a car, you can
call the Mazda
Customer Service line at (800) 222-5500 with the vehicle's
VIN, and they
can tell you.
The coolant recall involved the replacement of some cooling
with stronger/more heat resistant materials and lowering the
the cooling system from 1.3 bar to .9 bar. The parts
replaced were the
water pump seal, the water level sensor, the upper radiator
filler cap, the filler cap body, the thermostat gasket, the
leading to the throttle body, and the water hose leading to
Fuel line recall
The fuel line recall involved replacing the fuel lines under
manifold with lines made from a more heat resistant material,
a fan control unit that runs the cooling fans if the coolant
hot, even if the car is turned off.
The brake recall involves the replacement of a vacuum
check valve and
hose leading to the brake booster. The original
unit may stick when
oily and cold, preventing power assist under braking.
What is the "exhaust system overheat" light for?
The "exhaust system overheat" light is connected to a
inside the car, under the carpeting, by the passenger seat.
location of this sensor is just above the main catalytic
its purpose is to warn of excessive heat being generated by
When the temperature of the passenger floor reaches about 220
the ECU activates the relief air bypass and bleeds off air
otherwise go to the catalytic converter. This has the
effect of cooling
the catalytic converter.
When I start my car, the RPMs go to 3000. Why?
All 1993+ RX-7s have what is called an "Accelerated Warmup
revs the car up to ~3000 RPM when it is cold-started.
Its purpose is to
heat up the 02 sensor and first catalytic converter to
temperature as soon as possible. If you don't like the
thought of your
motor revving that high when cold, you can start the car in
(with the clutch in), and the AWS will only take the RPMs to
~1500 or so.
It is also possible to bypass the AWS solenoid (see the
of this FAQ).
What does the "mileage switch" do?
The "mileage switch" is in effect for the first 20k miles on
a new RX-7.
It has the same effect as the "power steering switch".
It adds some RPM
to the base idle to help keep the engine from dying.
What type of gas should I use?
The RX-7 requires "super" or "premium" unleaded gasoline.
gas with a 92 or higher octane rating. Using leaded gas
both your catalytic converters and your oxygen sensor,
What are some of the common problems with 3rd Gen RX-7s?
Common problems with easy fixes
Oil pressure gauge reads 0 psi
Sometimes the connection between the oil pressure sending
unit and the
wire to the oil pressure gauge gets loose or dirty. The
way to fix this
is to clean the metal tab on the sending unit with some 0000
and then re-install the gauge wire using some electrolytic
(like some sets of spark plug wires come with) to seal out
No boost above 4500 RPM
This is usually caused by a vacuum line coming off of
the "Charge Control
Solenoid". The lines sometimes pop off while
under boost. The solenoid
in question is located under the upper intake plenum.
Look in your
shop manual on page F-10, the solenoid is item F.
If a vacuum line has
come off here, trim off the end of the line where it
has become loose,
and re-attach it to the solenoid. It is helpful
to use wire-ties or
a dab of sealant to keep them from coming off again in
Motorcycle shops also sell small, wire clamps that work
Hood squeaks / rattles
Squeaks: Lightly lube up the tops of the rubber
hood stops and the latch.
Rattles: Tighten the latch mechanism so it holds
the hood to the rubber
stops with light pressure. Latch rattles can also
be temporarily fixed
by wrapping a small amount of tape around the latch
where it mates with
the striker plate.
Hand brake light comes on while driving
The switch that controls the parking brake indicator light is
under the leather brake handle boot. Sometimes during
hand brake lever moves enough to activate the light.
This problem can be
fixed by building up the area of the handbrake that contacts
with a product like JB Weld.
"Low Coolant" alarm goes off
The "Low Coolant" alarm goes off when the low coolant sensor
is not wet.
This sensor is located on the back side of the aluminum
housing. Simply top off your coolant level to quiet the
alarm (even though
it may already look full).
Radio flashing "Err" code
This means the factory radio's anti-theft feature has been
can be reset by entering an unlocking code. The
unlocking procedure is
at http://k-rad.com. Your dealership can also unlock
your radio, but
they will usually charge a fee.
Other common problems
Hesitation at 3000 RPM when cold
No known cure.
I think it is caused by the double throttle control.
Its purpose is to
prevent the engine from getting an overly lean fuel/air mix
first start to accelerate. Now the way this system
works is that when
the engine is cold, (coolant below 175 degrees or so) the ECU
double throttle control solenoid, which supplies vacuum to
throttle control actuator. This vacuum overcomes the
that normally holds the double throttle butterfly open, and
Now, think about what happens when you accelerate.... the
less vacuum, and starts to go towards positive manifold
pressure as you
build boost. With the vacuum going away, the plate
returns to its
open (normal when engine warm) position. This helps
explain why the car
doesn't hesitate when accelerating hard, and does when
The decision by the ECU to operate the double throttle
control system is
affected by coolant temperature, and the current "map" that
the ECU is
using. The Double Throttle control only happens during
engine warm-up, and COLD engine with LIGHT LOAD operation.
This map is
also affected by the 20k mile switch, which is why many
people say that
the car never hesitated at 3000 RPM when it was new.
The 20k mile switch
does the same thing that the EL switch does.... it adds base
RPM to the
motor... which affects the ECU's decision as to what "map" it
This is just my personal theory, and may be wrong.
Some RX-7 owners have experienced problems with accelerated
and fading. Mazda has set aside some money to deal with
this problem on
a case-by-case basis. If your car has this problem,
call the Mazda customer
service line (800 222-5500) and ask to schedule a meeting
with your local
District Service Manager to have your paint inspected.
Battery death & leakage
Many people on the RX-7 mailing list have had their batteries
prematurely. The main cause seems to be excessive heat.
don't do well with heat, and it gets quite hot under the hood
RX-7. Hot batteries also tend to leak acid. One
solution to this
problem is to buy a sealed battery. Sealed batteries
and cold much better than normal batteries, and they do not
Sealed batteries cost a little more than regular batteries,
but they also
last longer and come with better warranties.
Brake rotor warp age
Brake rotors warp from excessive heat. Routinely
braking hard from
high speed, can cause warpage. Rotors have been
replaced under the
new-car warranty. The extended warranties generally
don't cover rotors,
since they are expected to be consumed with use. Many
netters have had
their rotors replaced under warranty.
Cars produced prior to May 31, 1992 came from the factory
with noisy upper
a-arm bushings. Your dealership will replace the
bushings under warranty
with a modified part.
Cracking factory wheels
Some people on the net have noticed cracks where their spokes
join the rim.
There seem to have been two manufacturers of stock rims, one
type has a
curved area where the spoke joins the rim, and the other
joins at a 90
degree angle. All reported cases of cracking rims have
been on the 90
degree type rims.
Is my car normal?
Is my mileage unusually low?
The official EPA mileage ratings for the 3rd generation RX-7s
Manual transmission: 17 MPG City, 25 MPG
Automatic transmission: 18 MPG City, 24 MPG Highway
Real world experiences from the net vary from this. A
highly modified car
has gotten higher than EPA predicted mileage, but this is the
Most people on the net get lower mileage, with 12 MPG in
mixed city and
highway driving being a common number.
How much oil should my car consume?
The RX-7's engine consumes oil by design. It has oil
metering pumps that
actually inject oil into the combustion chambers to be burned
as you drive.
The amount you use will be determined by how aggressively you
Sometimes my car backfires, is this bad?
No. Backfiring is caused by unburned fuel being ignited
in your exhaust
system. Backfiring in itself, although annoying, is not
Excessive backfiring can be an indication of another problem.
What is typical 3rd Gen performance?
A typical, stock 3rd Gen should be able to turn about a 14.2
or better in
the quarter mile, and a low 5 second, or better, 0 to 60 time.
What are normal boost patterns?
According to the official Mazda test procedure, boost should
be as follows:
- Drive to third gear with normal acceleration
- Accelerate from 35 MPH at WOT until passing 4500 RPM
- A slight and smooth increase in power should be felt at
RPM. This will be about 65 MPH.
Boost should be above 10 PSI up to 4500 RPM. The boost
will drop to about
8 PSI just after 4500 RPM, and will begin rising towards
depending on the length of time the throttle is held wide
Performance / Competition
I want to race/modify my RX-7. How do I start?
Before racing or modifying your RX-7, you should start with a
car. Change your oil and filter, change your fuel
filter, bleed the
brakes, change your air filter, make sure your tires are in
and properly inflated. Use a little common sense and
make sure your
car is in good shape BEFORE you add the additional stress of
modification. This will also simplify any
troubleshooting you may have
to do, as it eliminates some variables. When modifying
your RX-7, change
one thing at a time if possible, this way you can more easily
part that is causing problems. As always, this is not
set in stone, for
example, you should not do anything that will dramatically
boost pressure without also adding fuel. Use common
This site is meant to give information related to the 1993
(o)Mazda RX-7 Twin Turbo. Anything from rotary engines to wiring diagrams and turbo upgrades to tuning info, this site has it all! efini 93 rx7 13b anfini Turbo RX-7 Turbo RX7 turbo rx7 rx7tt rx-7tt As well as the Rotary Engine Pickup Truck aka REPU repu