Mazda RX-7 User manual

MAZDARX-7
COM
PETITIONPREPARATION
ANDSERVICEMANUAL
@Copyright
1980byToyoKogyo
Co.,
Ltd.

CONTENTS
ENGINE
Basic
Specifications
l. Explanation
and
DescriPtion
of
Competition
Parts
ll. Additional
Required
Parts
lll. Machining
and
Fabrication
Operations
and
Procedures
lV. Checks
and
Measurements
V. Assembly
Operations
Vl. Checks
and
Adjustments
Vll. Operating
Procedures
cHASSTS
DRIVELINE
l. Explanation
and
DescriPtion
of
Competition
Parts
ll. Notes
on
Machining
and
Assembly
lll. Checks,
Adjustments
and
Practices
BRAKE
SYSTEM
Specifications
l. Explanation
and
DescriPtion
of
Competition
Parts
ll. MachiningOPerations
lll. Checks,
Adjustments
and
Maintenance
STEERING
AND
SUSPENSION
Specifications
l. Explanation
andDescriPtion
of
Competition
Parts
ll. Machining
and
Installation
Operations
' lll. Checks,
Adjustments
and
Maintenance
APPENDIX
Comparison
of
Specif
ications,
RX-7
and
5
B
8
13
21
21
24
RX-3 47
27
28
31
35
36
37
39
40
44

PREFACE
Toyo
Kogyo
Co.,Ltd.,
wishes
to extend appreciation
for
your
interestinandefforts
with
theMazda
RX.7
in automobile
competition.
ThisManual
reflectstheknowledge
gained
byMazda
competitors
and
Toyo
Kogyoengineers
through
much
research,devel-
opment
and
actual
competition,
and
is to be
considered
recommended
practice.
lt is
intended
foruse
onlyby
thoseseriously
engaged
intheconstruction
and
maintenance
ofthe
RX-7
in
competition;
the
parts,procedures
and
specifications
outlined
within
the
Manual
are
for
racing
and
competition
use
only,and
specif
ically
haveno
relationtoor
application
orother
purpose
for
street
and
highway-driven
automobiles.
lfthe
informa-
tion
contained
inthisManual
is
applied
toa street
orhighway-driven
RX'7,
the
results
may
include
voidedwarranties,
reduced
reliability,and
losses
in
performance,
economy
and
emissions,
all
orsome
of which
maybeillegal
in certainareas
and
which
are
def
initely
notapproved
by
ToyoKogyo
Co.,Ltd.
With
the parts,
procedures
and specif
ications
in the Manual
the competitor
.can
assemble
and
maintain
theengine,
drivetrain
and
chassis
components
and
the
various
appropriate
subsystems
involvedinacompetition
Mazda
RX-7.
The
individualcompetitor
should
beaware
that
many
ofthe
parts
and
procedures
outlined
in
this
Manual
may
not
beallowed
under
the
rulesand
regulations
ofcertain
competition
organizations,
and
itis
the
responsibility
of thecompetito(,
racer,
mechanic
orother
person
associated
with
racingaMazdato
have
a
fullunderstanding
ofthe
pertinent
rulesand
regulations
ofhis
comp-etition
governing
body.
For
instance,
the
readerwill
notice
there
isno
section
in
this
Manual
on
thedesign
and
construction
ofa
rollcagestructure,
as
thesedetails
and
requ
i
rements
varywithdif
ferentsanct
ioningorgan
izations.
In
competition
there
is
a
highdegree
ofexperimentation,
and
the
reader
is
assumed
to
understand
that
such
experimentation
isonan
individualbasis,
isnotcovered
bythis
Manual,
and
fromthe
position
ofToyo
Kogyo
Co.,
Ltd.,and
its
affiliates,
istherefore
categorized
as non-recommended
practice.
Toyo
Kogyo
Co.,Ltd.
is interested
in the
resufts
of any competition
experimentation
or experience,
but specifically
cannot
recommend
anew
procedure
until
ithas
undergone
athorough
analysis
byappropriate
company
engineering
staf
f.
In
any
formof automobile
competition
theindividual
is also
considered
to assume
responsibility
for
hisorher
actions,
and
to realize
andaccept
thatautomobile
compe'
tition
is,by
its
verynature,
ahazardous
activity
withahigh
degree
of
risk
of
damage
to
equipmen[
and/or
personal
injury.By
the
application
ofthis
Manual
it is
assumed
the
inbividual
willbe
operating
a competition
automobile
atorneartheouter
limitsof its
performance
envelope,
and
theclosertothose
limits
the
greater
the
risk.Neither
Toyo
Kogyo
Co.,
Ltd.,
nor
any
of
their
aff
iliates
oremployees
assume
any
responsibility
inany
manner
forany
losses,
eithrer
to equipment
orpersons,
resulting
from
the
use
of any
Mazda
automobiles
incompetition
ortheapplication
ofany
parts,
procedures
orspeci'
f
ications
outlined
inthis
Manual.
Finally,
automobile
competition
is
aconstantly
changing
area
ofendeavor,
subject
to
new
teihnology,
and
this Manual
is the current
best
recommended
practice
but is
subject
tochange,
without
nctice,atany
time.
Again,
thank
you
for
your
interestintheMazda
RX-7
inautomobile
competition,
and
we
extend
you
good
luckandbest
wishes
in
your
efforts.

Type 12ARotary
Displacement,
per
rotor 573cc
Displacement,total 1146cc
Compression
ratio 9.4:1
lntake
porting Peripheral
Exhaust
porting Peripheral
Carburetion Twinthroat,down
draft
Weber
Lubrication Wetsump
Cooling Liquid
lgnition Transistorized,
capacitivedischarge
(cDr)
Maximumallowable
enginespeed 9.000 RPM
ENGINE
BasicSpecifications
Explanation
and Description
of
CompetitionParts.
A. Housing
group.
1. Rotor
housing,
4352
10'100
It has
the following
differences
fromthe
stock
housing:
(1)
Theintake
porting
is
peripher-
al.
(2)
lt is
sandcast
fromlowervol-
ume
patterns.
(3)
Thecoolant
passages
aredif-
ferent.
(4)
Thetrochoid
surface
is
direct-
lychrome
plated
ontothe
cast-
inginstead
of beinga sheet
metal
insert.
The
intake
andexhaust
as
follows: timingis
2. Side
housings,
front:435210200
intermediate:
435210400
rear:4801
10300
ENGINE
They
differ
from
thestockhous-
ings
intheseways:
(1)
Theintake
ports
are
filledin
solid.
(2)
Theintermediate
housinghas
anoilseparatortank. :
(3)
The
passages
for
the
oil
pump
on
the
front
housing
arelarger
passages.
3. Tensionbolts,4352 10451A
These
arethe stockboltswith
rubberbondedto them which
dampensout
vibrations
atcertain
f
requencies
and prolongsbolt
life.
4. Stationary
gears,
front:4352
10500
rear:435210
550
Comparedto the stock gears,
thesehavethe following
differ-
ences:
(1)
For
strength,thematerial
and
heat
treatmentis
different.
(2)
Amachined
groove
aroundthe
bearing;thisfeatureenhances
bearinglife.
IntakeOpens86'
BTDU
Closes
75'ABDC
Stationary
Gear

ENGINE
Oil
pan,435210
700
This
isan
increased
caPacitY
Pan
to
maintain
pressure
under
racing
conditions,
particularly
while
cor-
nering.
Baffle
plate,
4352
10709
Thisbaffle
plate
will
maintain
an
adequate
oil
supPlY
around
theoil
pump
pickup
while
cornering
or
braking.
Botatlng
grouP.
1. Balancer
assemblY,435211
010
These
pieces
differ
f
rom
stock
bY
being
balanced
toa closer
toler-
ance.
2. Rotor,435211
100
The
competition
rotor
hasthe
fol'
lowing
features:
(1)
The combusion
chamber
is
the Medium DeeP Recess
(MDR)tyPe.
(2)
lt
hasasnap
ringtoretain
the
internal
gear
in
Place.
(3)
The
apex
seal
groove
ischrome
plated
to
reduce
wear.
standard:
10111'l
111
oversize:
1058
78
135
Theoversize
bearing
is available
to provide
thecorrect
oil clear'
ance,
and
is
larger
in
diameter
bY
30p
Apex
seal,4352
11301
Theapex
seal
is made
of carbon
and
is3.0
mmthick.
Apex
seal
spring,4352
11304
This
spring
is designed
sPecifi'
cally
for
the3.0
mmcarbonaPex
Side
seal,
4801
11
311
Compared
to
thestock
seal,
this
side
seal
ismolybdenum
treated
forincreased
wear
resistance.
Corner
seal,
1BB1
78146
The corner
seal has a sPraYed
molybdenum
coating
for
self
lub-
rication
properties.
Outer
oilsealsPring,
front:4352
11
353
rear:43521
1
363
The increased
pressure
of this
spring,
dif
ferent from original,
13kg/cm'as
compared
to
B
kg/cm'
forthe
slandard
oil sealspring,
prohibits
combusion
gasblowbY.
For
the
inneroil seal,
thestock
spri
ngissatisfactory.
Eccentric
shaft,4352
11400
The
material
and
conf
igurationof
this
shaft
are
identical
to stock,
but to reduce
the likelihood
of
bearing
seizure,
the rear
halfof
the
rear
main
journal
ismachined
20p.smaller
in
diameter,
as
shown
in
the
illustration.
(aD = A
- B)
7.
Rotorbearing,
aO
0

ENGINE
10.Drive
pulley,
435211
601
This
pulley
has
the
followingdif-
ferencesfromthestock
version:
(1)
The
materialis
aluminum
alloy
toreduce weightand
rotating
inertia.
(2)
Theoilseallip'scontactarea
has
been
treated
forwearre-
sistance.
(3)
Thediameter
is
90
mm.
11. Flywheel,4352 1
1755
Thisflywheelis fabricatedfrom
steelbut is significantlylighter
thanstock
to reducerotating
in-
ertia.
12. Needle
bearing,082278184
Theneedle
bearing
has
a higher
load
capacitytowithstand
severe
clutchengagements.
C. Intake andexhaust
group.
1. Intake
manifold,
435213100
This
manifoldhas
thefollowing
features:
(1)
ltiscastfromaluminum
alloy.
(2)
lthas
beendesignedtoaccept
and
workwiththeDDW48lDA
carburetor.
andto match
an
engine
installation
angleof
4"40'.
(3)
The
length
of theintake
pas-
sages
has beendetermined
foroptimumtuningandeffi-
ciencyat
the
designedengine
speeds.
2. Gaskets,
rotorhousing
to
intake
manifold:
086278205
intakemanifoldto
carburetor:
. 086278206
3. Carburetorsupport,0862
78240
This
support
reducesthetransfer
of
engine
vibrationstothe
carbur-
etor and thereby
prevents
fuel
surgingandbubbling.
4. Exhaust
header
and
pipe,
header:
435278250
pipe:4352
78260
Someofthe
mainfeaturesof
exhaustsystemare:
(1)
Boththeheaderand
pipe
are
fabricatedfromstainlesssteel.
(2)
Theheader
is
atubulardesign,
andthe
pipe
terminatesin a
megaphone.
(3)
The
header
and
pipe
are
join-
edbya sliding
connectionto
allow
forengine
vibration
and
movement.
5. Exhaust
system
support
brackets
See
page
10for
details.
D. Lubrication
group.
1. Oil
pump,
105878
220A
Theshaft
and
rotorsin thecom-
petition
oil
pump
aremoreresis-
tanttowearandseizing.
Oil
pressure
regulator
assembly,
435214
250
Thisregulator
will maintain oil
pressure
at
6.5
-r0.5
kg/cm'.
Engineoil
cooler,105878
180
This
larger-than-stock
coolerwill
increase
coolingcapacity
by 50
percent
over
stock.
E. Cooling
group.
1.Water
pump,4801
15
010
Thecompetitionwater
pump
is
aluminumalloy.
Water
pumppulley,4801
15151
To reduce weightthis pulley is
madefrom
aluminumalloy,and
itslarger-than-stock
130mmdia-
meter
will
enhanceV-belt
life
and
reduce
the speedof the water
pump.
Radiator,105878190
The
aluminumalloy
competition
radiator'slarger
corewill
increase
enginecoolingcapacity
by60
per-
cent
overstock.
V-belt,105878154
This
notchedV-beltismoreresis-
tantto
heat.
stretchand
vibration.
F. Electricalsystem.
1. lgnitioncoil,4801
1B100
This higheroutputcoil is exclu-
sively
designedfor use with the
Mazdacompetition
capacitivedis-
charge
ignition
(CDl).
2. Hightensionwires,
coil-to-distributor:43521B110
distributor-to-spark
pl
ugs:
48011B150
These
high
tensionwires
have
a
metalwire
coreto reducevoltage
drop.
3. Distributor,4B0l 1B200
Thesearethe mainfeaturesof the
distributor:
(1)
lt is breakerless,
havinga
magnetic
trigger.
(2)
Thereis no advance mechan-
ism.
2.
3.
2.
3.

ENGINE
4. lgnitor
and
lead
wiring,
ignitor:4801
18800
lead
wiring:4801
18870
This
fully
transistorized
ignition
will provide
a stable
secondary
voltage
at high
engine
speeds.
The
lead
wiring
harness
issPeci'
fically
intended
forthis
ignition.
Alternator
and
alternator
straP,
alternator:399718
300
strap:4801
18361
Alternator
pulley
part
number:
0833-78-1
53A
The
alternator
output
is
35
amPs,
and
its
pulley
diameter
is75
mm.
Starter
stay,4352
1B
401
spacer,
'1281
17
383
Thestarter
stay
reduces
vibration
and prevents
possible
breakage
ofthe
transmission
case.
Note:
When
installing
thestaY,
the
spacer
mustbe
inserted
between
thestay
and
thestarter
motor.
Spark
plug,
4352
18600
The
heat
range
of
this
Plug
is11.5,
which
iscolder
thanstock.
Fuel
pump,
4352
1B250
This
fuel
pumP
has
an
outPut
of
100
liters/hour.
Two
of them
are
needed
to satisfY
the
racing
en'
gine's
minimum
fuel
flow
require-
ment
of
180
liters/hour.
ll. Additional Required Parts.
TheseParts
must be acquired
from
outside
sources.
1. Carburetor.
This
engine
uses'a
Weber
48lDA
ofthe
following
sPecifications:
2. Tachometer.
We
recommend
using
a mechan-
icaltachometer.
Temperature
gauges.
Minimum
requirements
include
water
and
oil
temPerature
gauges.
Oil
pressure
gauge.
We recommend
a mechanical
gauge
of
the
Belden
tube
tYPe.
5.
6.
3.
4.
7.
8.
lll. Machining
and
Fabrication
Opera-
tionsand
Procedures
A. Fabricationof oil separatortank.
1. Use
the
stock
oil
filler
PiPe.
2. The
original
filler
pipe
is
toolong
and must havea 40 mm section
removed
from the middle.
Cut it,
reweld
and
drill
holes
asshown
in
the
illustration.
3. Fabricate
the
tank
as
shown,
and
weld
ittothe
filler
PiPe.
4. After
welding,
check
foranY
Pos'
sible
oil
leaks.
Eore
xVenturi
(mm) 48x43
Emulsion
tube F-8
Main
iet fi230
Main
air
corrector.iet #130
ldle
jet #80
ldleair
corrector
iel #120
Accef
erator
nozzle #50
Needle
&seat #300
Float
level 21-23
mm
from
the
upper
surface
ofthe
float
chamber.
ii ,,i
(F"y'
i''-.1
-_*,, n,
f( ))t
Y,'t

ENGINE
B. EGR
port
block-off
plate.
1. lfyour
intermediate
housing
has
anEGR
port,
it mustbe
blocked
off witha plate.
Werecommend
aluminum
approximately
3.0
mm
thick.
2. Wheninstalling
the block-off
plate,
usea gasket
orsome sili'
conesealant.
Metering
pump
holecover.
1. lf
themetering
PumP
shaft
isnot
usedas
a
mechanicaltachometer
drive,
the hole
mustbe covered
witha plate.
Make
the Plate
of
aluminum
approximatelY
3.0
mm
thick.
2. A gasket
mustbeused
withthe
hole
cover
plate.
D. Weber
carburetor
float bowlexten-
sion.
Forcourses
with
very
tight
orlong
corners,
this
floatbowlextension
will
help
prevent
fuel
starvation.
The
floatbowlextension
fabrica-
tion
procedure
is
as
follows:
Cut
anappropriate
holeonthe
sideofthef
loatchamber.
Fabricate
thebowlextension
fromsheetaluminum
as
shown
intheillustration.
Weldthe bowl
extension
to
the
floatchamberat
four
points
only;
if
you
weldallaround
the
carburetor
maydistort.
After
welding,sealthe bowl
extensionto the floatcham-
ber
withThreeLoy.
TheThree
Loymaybeheld
in
place
with
clayorsomething
similaruntil
ithardens.
(1)
(2)
(3)
(4)
f-{
ol
Tl
lct
YY
-l I
Y

ENGINE
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