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2013 JAF Grand Touring Car 300(JAF-GT300) Technical
Regulations
Article 1: Vehicle 1.1) Definition
Grand Touring Car 300 Automobile having two seats at least and
one or more doors on each side respectively for getting on
and off. 1.2) Eligibility as an original vehicle
Cars produced by an automobile manufacturer, comply with legal
requirements for road use and satisfy either of the following
conditions:
(1) homologated in FIA Group N/A/GT3/GT2/GT1, JAF Production
Touring Cars or Special Touring Cars,
(2) registered with JAF as registered vehicles. 1.3) Original
engine
An engine which is produced by its original manufacturer and is
legal for road use, and admitted by FIA and/or JAF.
1.4) Optional parts
The use of the optional parts which are mentioned in the FIA
and/or JAF homologation form or the JAF-GT main specifications
register form of the cars registered with JAF is authorized.
Article 2: Regulations 2.1) Modifications
Any modifications which are not permitted in this Chapter are
prohibited. General prescriptions and Safety
Cars must comply with the following requirements of Appendix J.
Art.252 "General prescription" and Art.253 "Safety", which are not
already covered in these regulations.
- 252.1) General remarks except for Art.252.1.2
- 252.2) Dimension and Weight - 252.3) Engine - 252.4)
Transmission
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- 252.5) Suspension - 252.6) Wheels - 252.7) Bodywork / Chassis
/ Bodyshell Replace Art.252.7.3 "Cockpit" by the following
text.
Cockpit The cockpit is that volume of the vehicle separated from
the rest of the vehicle by fixed front and rear bulkheads. For
2-volume vehicles, the cockpit is that volume between the front
bulkhead and the bulkhead behind the rear edge of the rear-most
seat. Remaining inner space behind that is referred to as the
luggage compartment. The bulkheads must be constructed of highly
flameproof rigid materials. The cockpit must be completely
insulated by the bulkheads from the engine compartment, fuel tank,
oil tank, gearbox, propeller shaft, and all joints of piping and
tubing (connecting these areas). Any and all devices/substance that
is potentially dangerous to the vehicle driver must be installed
outside of the cockpit (on the other side of the bulkhead). Only
the following accessories may be installed in the cockpit.
* Spare wheels * Tools * Spare parts * Safety equipment *
Communication equipment * Ballast (if permitted) * Windscreen
washer water container * Equipment for cooling suit
On 2-volume vehicles, the oil tank may be installed to the
luggage compartment provided that bulkheads are used to protect
against oil leakage and sparking.
except for Art.252.7.7 - 252.8) Electrical system - 252. 9) Fuel
Combustive Refueling tank must comply with drawing 252-7 with fuel
hose of maximum 5m in length, but
flow restrictor is not mandatory. - 252.10) Brakes - 253.1)
Dangerous car - 253.2) Optional device - 253.3) Lines and Pumps -
253.4) Braking safety system - 253.5) Additional fasteners - 253.6)
Safety belts - 253.7) Extinguishers - Extinguishing systems -
253.8) Roll over structures - 253.9) Rear view
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- 253.10) Towing eye - 253.11) Windows / Nets Except for the
following text
"The windows must be certified for road use, their marking
standing as proof." Add the following text.
Anti-dazzling treatment may be applied as a strip along the
upper edge of the glazed surface. The width of the strip must not
exceed 100 mm.
- 253.12) Safety fixing device for Windscreen - 253.13) General
circuit breaker Replace text "As for the out side, the triggering
system of the circuit breaker will compulsorily
be situated at the lower part of the windscreen mounting of the
drivers side for closed cars" by "As for the out side, the
triggering system of the circuit breaker will compulsorily be
situated at the lower part of the windscreen mounting of the
opposite side of drivers side for closed cars"
Add the following text. In vehicles whose design makes it
impossible to install the circuit breaker close to the lower part
of front windscreen mounting bracket, the circuit breaker may be
installed outside either of the passenger side center pillar or the
quarter pillar, which permits operation from outside.
- 253.14) FIA approved safety fuel tanks - 253.15) Protection
against fire - 253.16) Seats, attachments and supports - 253.17)
Pressure control valves
However, if the prescriptions which have the same meaning as
those of the above Articles are
defined in this Chapter, prescriptions in this Chapter should be
obeyed. 2.1.1) Material restrictions 2.1.1.1) Composite material
(Including carbon and aramid fiber)
If only the use of the material is authorized in this Chapter or
the use of the material is standardized on the specific parts or
areas of the original vehicle and engine, these composite materials
can be used in the relevant parts or areas.
2.1.1.2) Titanium and ceramics
Regardless of the provisions of the present regulations, the
following must be respected. 1) If the use of these materials is
standardized on the specific parts or areas of the original vehicle
and
engine, these materials can be used only in the relevant parts
or areas. 2) The use of these materials is permitted for the
following parts:
(1) connecting rods (2) intake and exhaust valves (3) valve
retainers (4) heat shield (5) apex seals (rotary engine) (6) brake
caliper pistons (7) supercharger
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2.1.1.3) Aluminum alloy
Regardless of the provisions of the present regulations, the
following must be respected. The use of aluminum alloy which has a
modulus of elasticity greater than 80Gpa is forbidden
except for brake calipers. 2.1.1.4) The other materials
Regardless of the provisions of the present regulations, the
following must be respected. The use of a material with a specific
gravity greater than 12.0 is forbidden.
2.1.2) Control function restrictions
1) Any automatic or electronic chassis control system or
function, excluding traction control system, is forbidden, even if
the original vehicle has it. This includes the systems listed in
the Appendix 1 of this Chapter.
A simple open-loop electrical switch activated by the driver
acting on a system is not considered to be electronically
controlled.
2) It is permitted to use (add) a speed limiter in order to
comply with the speed limit in the pit lane.
2.2) Compliance with the rules and regulations It is the duty of
each competitor to give an explanation and accept any checks at the
request of the
scrutineers and the Steward of the Meeting of the event
concerned in order to satisfy them that his car complies with the
rules and regulations in their entirety at any time during an
event.
2.2.1) Measurements
During the event, all required measurements will be made at the
location specified by the chief scrutineer and with measuring
instrument and apparatus which will be provided by the event
organizer. No protest can be accepted against these measurement
site, measuring instruments and/or equipment, and measurement
methods.
Article 3: Bodywork and exterior dimensions Save the
modifications authorized in this Chapter, dimensional
specifications of the original vehicle
mentioned in the homologation form and documents in relation to
the registered cars and also their outer shapes without bolts for
fitting must be maintained. 3.1) Dimensions 3.1.1) Overall
length
The overall length of the car must not exceed the sum total of
the dimensions of the overhang and the wheel base permitted under
Art.3.1.4) below.
3.1.2) Maximum height
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The dimension from the bottom surface of the flat bottom to the
top of the roof (roof reference plane without local projecting
shape, roof rail and auxiliaries such as antenna) must not be less
than 1,100mm when measured perpendicular to the bottom surface of
the flat bottom. In order to comply with this rule, it is permitted
to remove the side sill and the floor, and downward raise of the
side sill and moving of the position of the floor are also
permitted.
3.1.3) Minimum ground clearance
Ground clearance is measured from every direction of the
complete vehicle perimeter with tires at the pressure of 160kPa.
Clearance must be at least 45mm. Any and all suspended parts can
not be situated below this height.
3.1.4) Overhang and wheel base 1) Front overhang
The overhang may be extended up to 950mm. However it must not be
extended more than 120mm from the frontal edge of the front bumper
of the original vehicle.
2) Wheelbase When the dimension of the wheelbase is less than
2600mm, it may be extended by 5%. When the
dimension of the wheelbase is 2601mm or more, it may be extended
by 1%. However its midpoint may be changed within the range of
+/-30mm longitudinally from the midpoint of the wheel base of the
original vehicle which is regarded as a base point (this must be
notified to JAF with dimensions from the position definable.)
3) Rear overhang When the dimension of the rear overhang of the
original vehicle is less than 950mm, it may be
extended up to 950mm.
3.2) Windows 3.2.1) Front window
The front windshield must be in accordance with the rules under
Article 9 of Chapter 4 Safety regulations for homologated cars and
registered vehicles. However it is permitted ; 1) that a colorless
transparent film is attached to the surface of the front windshield
in order to protect
it. 2) that the material of the front windshield is changed into
polycarbonate of which thickness is no less
than 6mm instead. 3.2.2) The other windows
1) The window glass may be replaced with some other transparent
material which must permit the cockpit interior to be visible,
provided the same installation position, thickness, and shape as
the original glass are maintained.
2) Operational method and regulating system of the door window
glass may be changed providing that the original function of the
door window glass is maintained. To the door of driver's side, door
window glass may not be fitted, however, it is obligatory to
install protective nets defined under
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Article 22 "Net" of the Chapter 4 Safety regulations for
homologated cars and registered vehicles. 3) The window glass may
have openings, however the total area of the openings must not
exceed 15%
of the area of the each window concerned. There is no
restriction on the shape of the ventilation openings.
4) Air scoops may be installed to the outside surface of any
window glass. Maximum protrusion of the air scoop shall be 50mm
measured perpendicularly from the outer window surface.
5) Following the removal of auxiliary accessories such as
weather stripping and molding, it is permissible to install the
window glass (except door window glass) directly to the vehicle
bodywork.
6) The surface of the windows that are installed at the rear of
the door windows on the lateral surface of the car may protrude to
the plane of extended surface of the door window glass.
7) A partition window may be replaced with a firewall. 8) When a
tinted glass or a window film is used for side or rear windows, a
driver inside the car must
be visible at a distance of 5 meters. 9) Windows situated to the
rear of the door (of the front door for 4-door vehicle) and to the
rear of the
rear bulkhead may be devitrified. If it is devitrified by
painting, it must be clearly distinguished by the contrastive color
with the livery.
3.3Bodywork 3.3.1) Changes in bodywork materials
Materials of front and rear bumper, fender, bonnet (including
engine-cover), rear hatch gate and boot-lid components may be
replaced by plastic materials or light metals provided that these
substitutions maintain enough structural strength and do not result
in configurative changes. However, if the bonnet (including
engine-cover) and the rear hatch gate include glass component and
the glass material is changed, former part of glass component must
be clearly distinguished by a parting line. If the part is painted,
it must be clearly distinguished by the contrastive color with the
livery.
Nevertheless configurative changes may be made only if the
prescriptions of this Chapter so defined. It is permitted to remove
the reinforcement members on the back of the structures of bonnet
(including engine-cover), rear hatch gate and boot-lid provided the
structural strength of these structures are maintained.
3.3.2) Door
1) For the door configuration, it is permitted that its area
between the bottom surface of the flat bottom and up to 120mm above
it is removed, but the shape of the other part must be original.
The back of the door configuration may be altered.
2) The materials of the door can be changed into plastic
materials or light metals provided that this maintains sufficient
strength of the structure.
3) Door hinge can be changed only for the purpose of giving the
driver a quick escape from the car during accident. If a door hinge
is included in the part removed under 1) above, the relevant door
hinge may be changed.
For 4-door vehicle, four or more fasteners comply with 3.4.4)
may be used instead of door hinges
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and door locks when the function of opening/closing for rear
doors is retained. 4) If the door mirrors are moved, original door
mirror bases can be changed into plastic materials or
light metals. 5) For 4-door vehicle, rear doors may be widened
in their width. The width shall be limited to the
extended outer surface of the rear fender. However the
configuration of the car when viewed from the side must be retained
other than the part which is cut for forming wheel arch. The
function of opening/closing for rear doors is free.
3.3.3) Openings made in the bodywork 3.3.3.1) Openings in the
bonnet (including engine-cover), rear hatch gate and boot-lid
1) They may be made to allow dissipation of heat and cooling
provided the configurations of these covers are not modified
substantially. The openings are also allowed to be closed providing
the closed areas keep the original shapes or form outer enveloping
surfaces.
However the opening of the bonnet (including engine-cover) must
fulfill the following conditions: (1) It is situated 100mm forward
of the rear edge of the bonnet (including engine-cover). (2) The
longitudinal length of the opening is 1,000mm maximum from the rear
edge of the bonnet
(including engine-cover). (3) The maximum width is up to 625mm
to the right ant left respectively from the longitudinal car
centerline.
Drawing 7-1
2) They may be made in the rear hatch gate and boot-lid to allow
dissipation of heat and cooling provided the configurations of
these are not modified substantially.
3) Opening accompanied by a change in hatch gate configuration
may be made. However if it is made within the extent of the
original window, the change is limited within 15% of the original
window surface of the rear hatch gate and the total width of the
opening is 400mm which must be symmetrical to the longitudinal
center line of the car.
4) Louvers, ribbing or lips etc. of which maximum protrusion up
to 20mm may be installed and ducts which are connected to the
openings may be added. However when viewed from above these
openings must not permit the inside structure to be visible other
than that of the duct connected to an opening concerned.
the rear edge of the bonnet
Parallel lines of the rear edge of the bonnet
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3.3.3.2) Opening on fender
Cut-out (exit hole) may be created on the fender situated rear
of the rearmost part of the complete wheel to permit the escape of
air used to cool the brakes. The inside must not be visible through
this exit hole when viewed from above and the side.
However, when an exit hole used to provide an exit for air
already used to cool the brakes is situated behind the rear wheels,
except the part below the horizontal plane passing through the
center of the rear complete wheel, it must be covered either with a
louver or with a very fine wire mesh in order to allow nothing to
exit other than air.
When opening is made on the fender for passing an exhaust pipe,
the opening may have a gap up to half of the diameter of the
exhaust pipe.
3.3.3.3) Opening on ceiling
One opening may be made on the ceiling providing the following
conditions are respected: 1) It must be positioned no less 100mm
behind of the rear edge of the front windshield. However if it
is made for introducing intake air to the rear engine, it must
be situated behind the rearmost edge of the rear bulkhead (air duct
can be connected to the opening made on the ceiling).
2) Longitudinal length of the opening must not exceed the half
of the ceiling's total length. 3) Its maximum width must be 400mm
and symmetrical to the longitudinal centerline of the car. 4) It
must not protrude from the surface of the car except air scoops
which may be installed to the
outside surface of the bodywork, of which maximum protrusion
shall be 40mm measured perpendicularly from the outer surface.
5) When viewed from above, it must not permit the interior to be
visible. 6) The structure inside the cockpit shall be no more than
150mm underneath the inside surface of the
ceiling and also be 100mm minimum above the driver's head.
3.3.3.4) Openings on the side of the bodywork when an engine is
moved to the rear
When an engine is moved to the rear, openings can be made for
the rear doors in case of 4-door vehicle, and on the body side
panel at the rear part of the door in case of 2-door vehicle, for
the purpose of for example leading air for cooling of heat
exchanger providing the following conditions are respected: 1) (1)
In case of 4-door:
It should be situated inside the peripheral parting line of the
rear door and under the parallel plane passing 770mm above the
bottom plane of the flat bottom (The shaded portion of the Drawing
7-2). (2) In case of 2-door: It should be situated under the
parallel plane passing 770mm above the bottom plane of the flat
bottom and in the area determined by the backward extended lines
from the rear edge of the door parting line and the lower parting
line of the door and a plane perpendicular to the bottom plane of
the flat bottom passing the center of the rear wheel axle (The
shaded portion of the Drawing 7-3).
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2) It must not allow the inner part to be seen from the side and
above. 3) Louver-shaped is prohibited and air scoop of maximum 50mm
protrusion may be installed for the
opening. However the maximum width of the competition vehicle
must not be exceeded as a result.
Drawing 7-2
Drawing 7-3
3.3.3.5) Openings for the rear part of the bodywork Openings
situated at the rear of the bodywork must be covered with a very
fine wire mesh or a
punching metal etc. . 3.3.4) Hinges of bonnet (including
engine-cover), rear hatch gate and boot-lid
Hinges may be removed provided that the fasteners do not allow
bonnet, rear hatch gate and boot-lid to open during the vehicle in
motion.
Where the engine or the fuel tanks are installed, these
fasteners must be able to remove without tools.
Flat bottom
Frontal edge of the rear door
Lower parting line of the rear door
Flat bottom The backward extended lines from the rear edge of
the lower parting lineof the door
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The fasteners must be clearly indicated by a red (or contrastive
color) arrow.
3.3.5) Bodywork (monocoque structure) and bulkhead The original
bodywork (monocoque structure) and bulkhead must be maintained for
the cockpit
area other than the modifications specifically allowed in this
chapter. The shape and material of "the back end panel" are free
provided the external appearance of the car
is not modified, however bodywork structure that is not covered
with fender, bumper and finisher must be remained.
Other than the front and rear bulkheads, openings situated
originally in the cockpit may be sealed.
3.3.5.1) Front bulkhead (including cowl top) 1) Original front
bulkhead may be removed for installation of a new bulkhead which
isolates the
cockpit entirely. However, if the cowl top is also removed the
supporting structure for the lower edge of the front
window must be newly constructed. The material and the shape of
the cowl top cover are free. But it must not protrude from the
perimeter of the rear edge of the bonnet when viewed from the
front. 2) Opening which is connected to the opening defined under
Art.3.3.3.1) is permitted for the purpose
of ventilation of the cockpit provided the isolation function is
maintained. If the vent of the cockpit is connected to the duct
installed at the back of the bonnet (including
engine-cover), the connected part must be of the structure which
can prevent fire from intruding into the cockpit when a fire in the
engine compartment.
3) The area to which the front bulkhead reference plane (plane
on the front side of the car) may be installed:
The longitudinal position of the new bulkhead should be +/-250mm
from the original position of the original vehicle.
4) The shape and material of the front bulkhead, structure of
connection of the openings defined under Art.3.3.3.1) or a part
which seals the openings existed originally: Shape: free Material:
identical to that of the monocoque of the original vehicle and has
equal or greater
thickness than that. 5) Openings may be made for the purpose of
modifications permitted under Art.3.3.8)" Tunnel
installation to the floor part", 3.3.12.1) and by this
provision, and for connecting the tubular structure defined under
Art.3.3.6) "Bodywork structure fore of the front bulkhead and hind
of the rear bulkhead "to the rollcage. However if it is necessary
to create an opening its size must be minimal for its purpose.
3.3.5.2) Rear bulkhead
1) New bulkhead may be installed after the rear bulkhead of the
original vehicle is removed. 2) It is obligatory to install rear
bulkhead which is positioned behind the drivers seat when
viewed
through from the side and can isolate the cockpit completely.
However, minimum opening
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connected to the opening according to 3.4.3.1)-2) for the
ventilation of the cockpit is permissible on condition that the
cockpits isolation function is duly maintained.
Drawing 7-4
3) The shape and material of the rear bulkhead, structure of the
connection of the openings according to 3.4.3.1-3) or a part which
seals opening existed originally. Shape: Free Material: The
bulkhead or the part must be made of a rigid and sufficiently
fireproofing
material. (1) Material which is identical to that of the
monocoque of the original vehicle and has equal or
greater thickness than that. (2) Carbon fiber material having
honeycomb construction no less than 10mm thickness. (3) Carbon
fiber composite having no less than 3.5mm thickness.
4) A structure can be built, for which a plane extended
horizontally from the main bottom plane of the floor can be
connected with a plane extended from the main plane of the rear
bulkhead.
3.3.5.3) Rear midship-engine vehicles
The followings are adopted for rear midship-engine vehicles in
addition to the above 3.4.5.1)"Front bulkhead" and 3.4.5.2)"Rear
bulkhead":
1) The bulkhead separating the engine compartment from the
luggage compartment and the floor part
of the engine compartment and the luggage compartment may be
removed, save the members which affect the bodywork such as
reinforcement members for the floor part of luggage
compartment.
2) If the fuel tank is installed to the luggage compartment of
rear midship-engine vehicles, there must be no cut-out in the said
bulkhead.
3) Structural members supporting the bulkheads which isolate the
engine compartment from the luggage compartment may be changed into
a detachable construction provided that this construction does not
affect the strength of the bodywork.
3.3.6) Bodywork structure fore of the front bulkhead and hind of
the rear bulkhead
Area permitted for bulkhead
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Main structure (structural framework) situated fore of the front
bulkhead and/or hind of the rear bulkhead may be cut and replaced
by the tubular structure which is connected with the rollcage.
The material of the outer plane behind the rear bulkhead which
serves also as a part of body structure (monocoque structure) may
be replaced by synthetic resin or light metals provided that
substantial strength and the shape, excluding permitted conditions
defined under 3.4.3.3) "opening on ceiling", are maintained . The
plane may be removable only when it can be separated from each
door, fender and boot-lid. However, no play or gap between the part
and the silhouette is permitted when seen from the front, the rear
and the side and it must be secured rigidly by hinges, a locking
mechanism or the four or more fasteners defined under Article
3.4.4).
When the main structure(structural framework) fore of the frond
bulkhead is replaced by the tubular structure connected with the
rollcage, it is obligatory to install a crushable structure defined
under Article 12.5) of the present regulations.
A tubular structure must conform to the following conditions: 1)
Material: steel 2) Yield strength: endurable with 5.5W
longitudinal, 1.5W lateral and 1.5W vertical loads
(W=1,500kg) (1) Parts to which the above loads are applied:
Front tubular structure: attachment points of the crushable
structure Rear tubular structure: the rear edge of the tubular
frame concerned
(2) Conditions when the above loads are applied: (1) The floor
part of cockpit is fixed (2) In running order (example; holes for
the fixation of the suspensions are not closed. If an
engine, a gear box or a flat bottom etc. has a function as a
stress member, it remains on that part.)
(3) The following verification of withstanding against the
obliged yield strength shall be submitted to JAF: (1) The result of
the static load test, of the strength calculation (calculation
report) or of the
analysis of the strength must be presented to JAF. (2) Drawing
of rollcage and tubular flame general construction and tube
material &
dimensions. It is not necessary to present the verification
every year unless the vehicle type and its
design remain the same. 3) Method of fixation to rollcage,
diameter and thickness of pipes
Free, including shape of the tubes. However any processing or
modification to the rollcage homologated by FIA or JAF
following
the fixation of a tubular structure is not permissible. 4) Even
if the engine is dismounted, the parts which suspend the bodywork
must work normally.
3.3.7) Flat bottom and floor
It is obligatory to install a flat bottom which complies with
the following conditions. The flat bottom must be installed across
the total width of the car seen from its underneath without tire
wheel
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housing and outer mirrors. 1) A solid body that is rigid, flat
and impervious plane under any circumstance, which covers the
lower surface of the car between the center line of the
rotational axle of the front wheel and the center line of the
rotational axle of the rear wheel must be secured.
Materials are free. Minimum width of the flat bottom is 950mm
and it shall be symmetrical about the longitudinal
center line of the car. This plane may be composed of several
pieces. However the gap of each piece between them
must be less than 1mm and the tolerance in vertical direction
across the whole plane area is 5mm maximum.
2) In any case, the flat bottom must not have an aerodynamic
effect. 3) No air stream may pass between the floor of cockpit and
the flat bottom except the parts fore of the
bulkhead, of passing the exhaust pipes(except side sill), center
tunnel and tunnel for rear engine vehicles.
Drawing 7-5
4) Any suspended part of the car, regardless of the provisions
under Art. 3.5.1) "Front aerodynamic device" of the present
regulations, must not situate below the plane formed by the flat
bottom.
5) It is permitted to have radius of maximum 25mm upwardly at
the periphery edge of the flat bottom. 6) Openings may be made into
the flat bottom for the following reasons.
(1) Pneumatic jack use (2) Extraction of heat from the exhaust
pipe ;
- The holes should be within the area corresponding to exhaust
pipe diameter. - The holes must follow the shape of exhaust pipe. -
Maximum diameter is 50mm
Bulkhead
Floor
Center line of the front wheel rotational axle Center line of
the rear wheel rotational axleFlat bottom
Front edge of floor
Front edge of flat bottom Rear edge of flat bottom
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- Number of the ventilation holes is free. (3) Sensor use
(Maximum diameter is 20mm)
However, for the purpose of passing the optical axis of the ride
height sensor, it is permitted to make maximum 4 holes (slits) of
the dimensions of 20mm x 50mm (maximum).
7) The flat bottom can be installed in such a way that the
straight part of lower surface of side sill except flange is the
top of it. However if the flat bottom interferes with the floor of
the original vehicle, the original floor may be modified or new
flat floor of the material prescribed in Article 3.3.9.1.-2) "Shape
and material" may be created.
8) In order to mount the flat bottom, part situated below the
straight line of the lower surface of the side sill may be bent or
cut.
Drawing 7-6
9) Provisions under Art. 3.4.12.1)- (3) "The shape of the tire
housing" shall be satisfied. 3.3.8Tunnel installation to the floor
part
1) Center tunnel A new tunnel may be created following removal
of the center tunnel of the original vehicle within the following
dimensions. Material: must be rigid and sufficiently fireproofing
material. (1) Material which is identical to that of the monocoque
of the original vehicle and has equal or
greater thickness than that.
Fender arch
Side sill
Flat bottom
Fender arch
Straight line of the lower surface of the side sill
Side skirt Side sill
Section
Flat bottomFloor
Bend or cut
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Drawing 7-7
2) Tunnel installation for exhaust pipes (1) One tunnel may be
installed of which width up to 210mm and height up to 210mm
provided it
does not affect the shape of the flat bottom toward the upper
direction of the floor. However if a car has an engine having
banking on its RH and LH at the front, it is permitted to install
one tunnel for the RH and LH respectively.
(2) The processing to the surface of the bulkhead should be
limited to a circumscribed square with a diameter up to 210mm.
3.3.9) Body side panel and side sill 3.3.9.1) Body side panel,
side sill and floor
1) Body side panel, side sill and floor situated below the
parting line at the lower part of the door window may be newly
installed after original body side panel, side sill and floor are
removed.
2) Shape and material: Shape: free However outer surfaces of the
body side panel and the side sill must be situated no more than
250mm above the bottom surface of the flat bottom and between
120mm transversely inward from the lower edges of the door outer
surfaces. But modifications permitted under Art.3.3.8)-2) "Tunnel
installation for exhaust pipes" is permissible.
Material: rigid and sufficiently fireproofing material composed
of the followings: (1) Material which is identical to that of the
monocoque of the original vehicle and has equal or
greater thickness than that. (2) Carbon fiber material having
honeycomb construction no less than 10mm thickness. (3) Carbon
fiber composite having no less than 3.5mm thickness.
3) The structure which allows air to pass inside the side sill
is prohibited. 4) To the lower part of the door between the front
fender and the rear fender, side sill cover may be
installed following widening of outer surface of the original
vehicle (door outer panel, outer surface of the side sill or outer
surface of side sill cover), however parts not widened must
maintain identical surface with the original vehicle.
The structure which allows air to pass between the outermost
surface of this part and side sill is
Rear Bulkhead
Front Bulkhead Lower surface of the flat bottom
Symmetrical to the center line of car
Permitted volume with dimensions for installation of center
tunnel
800mm
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prohibited. When an opening is made for the purpose of passing
exhaust pipe on the outmost surface, it should be limited to a
circumscribed square with a diameter up to 120mm when viewed from
the side.
5) If the side sill cover is installed, its material is
free.
Drawing 7-9
3.3.10) Bumpers 3.3.10.1.1) Front bumper
1) The shape of upper part which is divided by a horizontal
plane passing 300mm above the flat bottom base must be retained as
original between the base points P1 and P2 of the Drawing 7-10. P1
and P2 are the points where a straight line having 75% of the
maximum width of the original vehicle which intersect vertically
with the longitudinal centerline of the car and symmetrical to
it,
Door
Door
Flat bottom
Flat bottom
Side skirt
Side skirt
Exhaust pipe
Outer surface of body side panel & side sill
Body side panel & side sill
Body side panel & side sill
Side sill cover
Side sill cover
Lower edge of the door outer surface
Door lower edge
Exhaust pipe tunnel
Drawing 7-8
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contact with the perimeter of the front bumper when viewed from
above. 2) Between the base points P1 and P2 (Drawing7-10) defined
above 1), the bumper part situated more
than 40mm and 300mm or less above the bottom surface of the flat
bottom may be modified (including addition of opening) if the area
falls inside the contour of the original bumper.
3) There are no restrictions on reinforcement members for the
inside of the bumper. 3.3.10.1.2) Rear bumper
1) The shape of the upper part between the base points P3 and P4
on the Drawing 7-10 and aloft the horizontal plane passing 300mm
above the bottom surface of the flat bottom must be retained as
original. P3 and P4 are the points where a straight line having 80%
of the maximum width of the original vehicle which intersect
vertically with the longitudinal centerline of the car and
symmetrical to it, contact with the perimeter of the rear bumper
when viewed from above.
2) Modification(including cut) of bumper configuration situated
lower than 300mm from the bottom surface of the flat bottom may be
permitted within the area determined by the rear axle center line
and the line parallel to it at the rear edge of the bodywork and
the straight lines at an angle of 30in relation to the latter at
the points laying 665mm from the longitudinal centerline of the car
each side and the lines parallel to the longitudinal centerline
which contact with the outmost perimeter of the bodywork (refer to
Drawing 7-11). However horizontal surface must be maintained at the
bottom of the modified bumper within 650mm from the longitudinal
centerline of the car each side.
3) There are no restrictions on reinforcement members for the
inside of the bumper.
W1: 75% of the maximum width of the original vehicle W2: 80% of
the maximum width of the original vehicle
Drawing 7-10
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Drawing 7-11
3.3.10.2) Changes in bumper configuration accompanied by
widening of fender width
These changes in bumper configuration are permitted subject to
the following conditions only. In order to facilitate examination
of the configuration change, participants must carry a template
with them. 1) Permissible area for the changes of front bumper
configuration This must remain within the area determined by the
straight lines at an angle of 30 in relation to
the lines connecting base points P1 & P2 and the straight
lines parallel to the longitudinal centerline of the car which
contact with the outermost perimeter of the bodywork (refer to
Drawing 7-10). Furthermore, R in some degree must exist at each of
the intersection points when viewed from above.
However, the front bumper situated within the area defined under
the relevant regulations must not be in the shape of canard or
similar to it (ledge shape extended longitudinally).
2) Permissible area for the changes of rear bumper configuration
2)-1 Part above a parallel plane passing 300mm above the flat
bottom base. This must remain within the area determined by the
straight lines at an angle of 30 in relation to
the lines connecting base points P3 & P4 and the straight
lines parallel to the longitudinal centerline of the car which
contact with the outermost perimeter of the bodywork (refer to
Drawing 7-10). Furthermore, R in some degree must exist at each of
the intersection points when viewed from above.
2)-2 Part under a parallel plane passing 300mm above the flat
bottom base. When seen from above, modification of the rear bumper
in this area is permitted if it remains
within the area determined by the rear axle center line and the
line parallel to it at the rear edge of the bodywork and the
straight lines at an angle of 30in relation to the latter at the
points laying 665mm from the longitudinal centerline of the car
each side and the lines parallel to the longitudinal centerline
which contact with the outmost perimeter of the bodywork (refer to
Drawing 7-11). Furthermore, R in some degree must exist at each of
the intersection points when viewed from
Extended line from the base of the flat bottom
Longitudinal center line of
car
Center of rotationalaxle of rear wheel
Overall width of the car
Rear edge of the car
Rear edge of the car
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above. 3.3.11) Fenders
1) Fender may be widened up to 1,950mm within the overall width
of a car. The front part of the front fender and rear part of the
rear fender must be fit within the area defined under Article
3.3.10.2) "Changes in bumper configuration accompanied by widening
of fender width "when seen from above.
The rear edge of the front fenders must not extend over the
parting line at the front edge of the doors (the dimension of front
fender may not be increased in longitudinal direction).
Drawing 7-12
2) The design of the fender parts which are extended is free,
however opening made must respect the provisions of Art. 3.4.3.2)
"Opening on fender" of the present regulations and have radius of
5mm or more at projected parts having acute angles on the outer
surface of a car, the fender parts which are not extended must have
identical surface with the original vehicle.
3) When the fenders of the original vehicle have openings for
intake and cooling for the engine, it is permitted that the
dimensions of the openings are altered or the openings are closed
as a result of extension of the fenders. However it is obligatory
to respect the provisions of Art. 3.4.3.2) "Opening on fender" of
the present regulations even in the former case.
4) Bumper and fender construction where the bumper extends into
the inside of the fender are permitted only if this is the original
vehicle design.
5) Fender must not protrude beyond the perimeter of the upper
edge of the fender of the original vehicle viewed from the side.
However if the tire housing installed in accordance with the
prescriptions of 3.3.12)"Tire housing" interferes with the fender,
the curved part which contacts with the installed tire housing may
protrude from the perimeter of the upper edge of the fender and the
relevant projected part may be connected with its circumference
smoothly (by smooth radius).
Parting line at the front edge of the doors Fender cannot be
extended to the rear of the line
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Drawing 7-13
6) If the original rear fender and rear pillar are of integral
construction, the fender is considered to be below the horizontal
plane passing through the lower edge of the rear window.
3.3.12) Tire housing 3.3.12.1) In order to allow the tire
housing to accommodate the front/rear complete wheel, an
independent
tire housing which is formed by the planes inside of wheel arch
must exist regardless of the structure of the original vehicle.
There are no restrictions on tire housing materials. 1) Tire
housings must be installed within the area defined below, with the
complete wheels in the
straight ahead position and the car in running order. (1)
Parallel to the bottom surface of the flat bottom, and above the
plane passing through the
wheel center line: In the area within a radius of 410mm of the
wheel rotational axle. The transverse position (to the right and
left of the car) is free.
(2) Parallel to the bottom surface of the flat bottom, and below
the plane passing through the wheel center line: In the area
delimited by the planes passing the center of the rotational axle
of the right and left wheels and parallel to the plane
perpendicular to the bottom surface of the flat bottom, and within
410mm to the front and the rear respectively. The transverse
position (to the right and left of the car) is free.
(3) The shape of the tire housing (1) The shape of the tire
housing is free. (2) The tire housing and the bodywork structure
which are situated less than 50mm above the
bottom surface of the flat bottom in the area of the tire
housing situated behind the frontal edge of the flat bottom and in
front of the rear edge of the flat bottom must be covered by the
flat bottom when seen from its underneath.
Smooth radius
Parting line of the fender of the original vehicle
Smooth radius
Projecting part as a result of construction of the tire
housing
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Drawing 7-14
(4) Opening may be created on the aft part of the tire housing
which is connected to the
cut-out(exit hole) permitting the escape of air used to cool the
brakes created under Art.3.4.3.2) "Opening on fender".
(5) Creating opening is permitted for the purpose of passing
sprung parts, driving device and ducts for cooling the brakes and
of extracting heat from the exhaust pipe.
2) If the tire housing of the original vehicle was constructed
already beyond the size defined by 1) above, it must be within the
dimensions of the original vehicle.
3) However where the front edge or the rear edge of the tire
housing interfere with the bulkhead, modifications may be made
solely in the area within a radius of 460mm of the front wheel axle
rotational center with the wheels in the straight ahead position
for the front bulkhead, and in the area within a radius of 410mm of
the rear wheel axle rotational center for the rear bulkhead.
Flat bottom
Flat bottom Flat bottom
Radius 25mm
Rear tire housing
Rear tire housing Rear tire housing
Rear tire housing
Flat bottom
Flat bottom
Flat bottom
Flat bottom
Flat bottom Flat bottom
Examples of the front tire housing
Examples of the rear tire housing
The angle is free
Radius 25mm
The angleis free
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4) The side sill exists within the area defined by 3) above may
be removed.
3.3.12.2) In order to build tire housing, it is permissible to
remove original side rail-uppers and the framework around it on
condition that there is no decrease in the structural rigidity,
except when any upper attachment point of suspension struts is
installed to the parts concerned.
3.3.12.3) Where the drive-shafts interfere with the side
members, the parts concerned may be modified
within the smallest possible area. However in order to maintain
the structural rigidity which might be altered by the modification
carried out, the modified parts must be reinforced.
3.3.13) Side skirts
Side skirts are permitted on condition that, and there are no
restrictions on side skirts materials. 1) it is installed below the
horizontal plane passing through the center of the front and rear
wheel
rotational axles of the car in running order. 2) within the area
(width) extended by the maximum vehicle width. 3) The front/rear
edge and the lateral edges must have a radius of more than 5mm. 4)
The outer surface of the side skirts may not enter the inside of
the outer surface of the original
vehicle. 5) Furthermore it must be connected to the flat bottom
without any gap and also to the front/rear
fenders. 3.3.14) Engine compartment 3.3.14.1) Radiator support
and its supporting members may be removed. 3.3.14.2) Bonnet
(including engine-cover)
If the tire housing installed in accordance with the
prescriptions of 3.3.12)"Tire housing" interferes with the bonnet
(including engine-cover), rear hatch gate or boot-lid , the
relevant part which contacts with the installed tire housing may
protrude in a curved shape follows the upper edge of the tire
housing. The relevant projected part may be connected with its
circumference and the fender smoothly (by smooth radius).
3.3.15) Luggage compartment
The floor of the luggage compartment may be modified or removed
but the ground may not be seen. 1) If the floor of the luggage
compartment is modified;
1.1) When any rear aerodynamic part does not exit under the
floor: (1) The shape shown in the drawing 7-15A is prohibited. (2)
The floor surface must be flat and parallel to the flat bottom (see
drawing 7-15B). (3) When the floor surface is flat and parallel to
the flat bottom, it can be lowered by the level
of the flat bottom. 1.2) When rear aerodynamic part exists under
the floor :
(1) When rear aerodynamic part under the floor exists to the
rear edge of the car, the shape of
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the floor surface situated above it is free (see drawing 7-15C).
(2) When rear aerodynamic part under the floor does not exists
longitudinally to the rear
edge of the car, the shape of the floor surface behind its rear
edge must be flat and parallel to the flat bottom as well (see
drawing 7-15D).
(3) Air must not flow in longitudinal direction between the rear
aerodynamic part under the floor and floor surface.
Drawing 7-15
1.3) Regardless of existence of rear aerodynamic part under the
floor, only the air passed through radiator may flow in the space
situated above the floor surface of luggage compartment. If the air
flows (in the space) over the lowest surface of the bodywork (floor
surface of the luggage compartment) and the purpose of that opening
is the escape of air which passes through radiator installed inside
the luggage compartment etc., the cross section of the opening must
be less than the area of the radiator core.
2) When the floor of the luggage compartment is removed; (1) It
is permitted install a crushable structure in order that the
influence resulted from these
changes against impact must be minimal. (2) In order to provide
greater rigidity for the bodywork, cross-members can be freely
added.
3) If a safety fuel tank installed in the luggage compartment;
Appropriate steps may be taken to prevent the fuel tank from
falling. This includes the addition
of structure by reinforcement- members to secure its safety.
3.3.16) Hard top for open cars
Provided the following conditions are observed, hard top for
open car may be installed. 1) Configuration: If the original open
car has a soft top or a hard top as its optional parts, the hard
top
which may be installed must maintain its configuration similar
to the original. 2) Material: rigid and sufficiently fireproofing
material and must be either of the followings, except
the attachments (including flanges); (1) Material which is
identical to that of the monocoque of the original vehicle and has
equal or
greater thickness than that. (2) Carbon fiber material having
honeycomb construction no less than 10mm thickness
Flat bottom
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(3) Carbon fiber composite having no less than 3.5mm thickness.
3) The highest point: The highest point indicated in the 3-
view-drawing of the catalogue of the
vehicle concerned should be regarded as the highest point of the
car. 4) Fixation: There is no restriction on its fixation method.
However fixing to homologated rollcages
may be authorized only if there is no need to carry out any
modification to the rollcages.
3.3.17) Vehicle interior With the exception of the luggage
compartment, vehicle interiors must remain as they were in the
original vehicle (Any mechanical structural element must not
exist other than that is originally installed in the vehicle).
Modification and replacement of the dashboard (instrument panel)
are permitted. But complete removal of the dashboard (instrument
panel) is not permitted.
Flexible air ducts made of non flammable material may be
installed to the vehicle interior for the purpose of cooling the
driver and various auxiliary equipment(electrical equipment). It is
also authorized that the flexible ducts are connected with air
scoops specified in Article3.3.19) "Auxiliary accessories" of the
present regulations, however it must not obstruct driver's
visibility.
Oil tank installation to the vehicle interior (cockpit) is not
permitted.
3.3.18) Reinforcement Reinforcement of the bodywork (including
bulkhead) is free provided it does not encroach on the
spaces inclusive of driver's and passenger's compartments.
3.3.19) Auxiliary accessories Demisting devices and cockpit
ventilation systems are free provided that the original
ventilation
openings are remained and the outside shape is not significantly
changed (Maximum protrusion 20mm).
3.4) Aerodynamic device 3.4.1) Front aerodynamic device
(1) The device may be installed under the bodywork within the
area determined by the parallel line max. 950mm forward of the line
connecting the axle centers of right and left front wheel and the
straight lines at an angle of 30in relation to the fore-mentioned
parallel line at the points laying 460mm from the longitudinal
centerline of the car and the lines parallel to the longitudinal
centerline which contact with the outmost perimeter of the
bodywork. This area must also be 130mm or less above the base of
the flat bottom.
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Drawing 7-16
(2) Materials are free. (3) The frontal edge and the lateral
edges should have a radius of more than 5mm. (4) Lower structure of
the bodywork may be connected to the lower part of the fender which
is
situated forward of the vertical plane passing through the
foremost point of the front complete wheel.
(5) For the examination of (1), participants must carry a
template with them. (6) Flap (canard) may be installed in the area
(Drawing 7-17);
(i) below the horizontal plane passing 250mm above the bottom
surface of the flat bottom of the car;
(ii) forward of the front complete wheel and outside of the
points P1 and P2 ; (iii) inside the parallel line max. 950mm
forward of the line connecting the axle centers of
right and left front wheel and the straight lines at an angle of
30in relation to the fore-mentioned parallel line at the points
laying 460mm from the longitudinal centerline of the car and the
lines parallel to the longitudinal centerline which contact with
the outmost perimeter of the bodywork.
(iv) be 120mm or less from the perimeter of the bodywork.
Front edge ofthe flatbottom
Front axle center
Front wheel axle centerline
Flat bottom
Front aerodynamic device Height limitation at front and rear
edges
Front edge of the flat bottom
Overall width of the car
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Drawing 7-17
3.4.2) Rear aerodynamic device
As a rear aerodynamic device, either a rear air spoiler or a
rear wing may be installed provided the followings are observed: 1)
Number of the device should be one unit. 2) The wing should be one
and any part of the aerofoil section should be able to fit in a
400mm150mm rectangle (including gurney-flaps, excluding supports
and end plates). 3) Its height should be limited by the top of the
ceiling except optional parts(1,100mm above the
bottom surface of the flat bottom). 4) The maximum width is
1,900mm (including supports and end plates). The area determined by
the line parallel to the rear axle center line at the rear edge of
the
bodywork and the straight lines at an angle of 30in relation to
the line at the points laying 665mm from the longitudinal
centerline of the car each side and the lines parallel to the
longitudinal centerline which contact with the outmost perimeter of
the bodywork (refer to Drawing 7-18) is to be regarded as the
outermost edge of the perimeter of bodywork, and the above
mentioned rear device may be installed within this extent.
Front wheel axlecenterline
Overall width of the car
Flat bottom
Overall width
75% of theoriginal car
The longitudinal centerline of the car
Canard
point
Max.
Max.
Section
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Drawing 7-18
5) It should be placed above the perimeter of the bodywork and
the parting line of the rear fender when viewed from the side, or
on the surface of the boot-lid (engine-cover).
(It is not permitted to install any aerodynamic device onto the
rear fender.) 6) It should be situated behind a plane vertical to
the bottom surface of the flat bottom and passing
through the center of the rear wheel rotational axle. 7) The
frontal edge and the lateral edges including end plates should have
a radius of no less than
5mm. 8) The shape and materials are free. When installing the
device to the boot-lid, it is permissible to
install reinforcements to the inside of the boot-lid to provide
greater rigidity for the fixation of supports.
9) The boot-lid and rear hatch gate should be able to be opened
and closed without removing any structural part.
3.4.3) Aerodynamic devices beneath the rear floor
It is permitted to add a completely flat inclined panel without
openings under the following conditions.
Under the floor no less than 350mm behind the center of the rear
wheel rotational axle and 650mm from the longitudinal center line
of the car on each side, it is permitted to install only
aerodynamic parts mounted to the original vehicle or a completely
flat inclined panel without openings (inclined panel) under the
following conditions. Neither the said aerodynamic parts nor the
inclined panel may be installed, but they can not be installed
together.
However if any structural part of the car interferes with the
inclined panel when the frontal edge of the inclined paned is
moved, the part concerned may protrude in a shape of rectangular
parallelepiped which is parallel to the surface of the flat
bottom.
Rear wheel axlecenterline
Rear wing
Rear edge of the car
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Materials are free. Regardless of the existence of the inclined
panel, free for the area beyond 650mm from the
longitudinal center line of the car on each side and aft of the
plane vertical to the bottom surface of the flat bottom and passing
through the center of the rear wheel rotational axle, and also
under the parallel plane passing 300mm above the bottom surface of
the flat bottom. 1) Between the vertical planes, one passing
through the rear edge of the flat bottom (a vertical plane
passing through the center line of the rear wheel rotational
axle) and the other passing through the rearmost point of the
bodywork.
2) Maximum width of the panel is 1300mm and it shall be
symmetrical in relation to the longitudinal center line of the
car.
3) No part of the panel may be situated more than 150mm above
the flat bottom. 4) Exhaust pipe and air-cooled cooler radiator are
permitted to be installed.
Drawing 7-19
5.1) Shielding is optional and may be installed on the lateral
part of the inclined plate. Materials and the shape are free when
it is installed.
5.2) If there is any removable auxiliary part such as a grill at
the rear of the original vehicle, it may be removed providing the
following conditions are respected:
When a bodywork part exists under the auxiliary part and no gap
exists between it and the inclined panel, the space created after
the auxiliary part is removed should be covered according to the
Art. 3.3.3.5) "Openings for the rear part of the bodywork" of the
present regulations.
6) The junction between the rear edge of the flat bottom and the
foremost point of the inclined panel must be continual and may have
a radius of up to 25mm.
7) Vertical fins may be installed under the following
conditions, Materials are free: (1) They remain parallel to the
longitudinal center-line of the car. (2) They exert no aerodynamic
influence. (3) Maximum 4 fins (4) Vertical fins may be extended
from the rear edge of the panel to the rear, however the
highest
Flat bottom
Inclined panel
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edge within the width of 1,300mm must not be more than 150mm
from the flat bottom and the rear edge must be situated inside the
outline of the car. When the upper extended part is fixed to the
bodywork openings must be made according to the Drawing 7-20.
Drawing 7-20
8) Openings may be made into the inclined panel for the
following reasons:
Inclined panel
Inclined panel
Inclined panel
The lower surface of the bodywork structure
The lower surface of the bodywork structure
The lower surface of the bodywork structure
Space
Vertical fin
Vertical fin
Vertical fin
The ground must not be seen when aboot-lid(trunk) or a hatch
gate is opened
Vertical fin extended from the rear edge of the panel to the
rear
Vertical fin extended from the rear edge of the panel to the
rear
Vertical fin extended from the rear edge of the panel to the
rear
Bracket to install vertical fin extended from the inclined panel
to the rear Circle of the
diameter of 50mm
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(1) Pneumatic jack use (2) Extraction of heat from the exhaust
pipe.
- The holes should be within the area corresponding to exhaust
pipe diameter. - The holes must follow the shape of exhaust pipe -
Maximum diameter is 50mm. - Number of the ventilation holes is
free.
(3) Sensor use Up to 2 openings with the maximum dimension of
20mm x 50mm
9) If rear aerodynamic part is installed under the floor and its
dimension from the longitudinal center line of the car to the right
and left is less than 650mm respectively, it is not permitted to
install any structure except exhaust pipe and oil cooler (including
its lines) in the area defined by its edge and by the lines
situated 650mm from the longitudinal center line of the car.
Article 4: Weight 4.1) Minimum weight
Minimum weight must be respected as laid out in the Appendix 2
of this Chapter. The JAF may change the minimum weight requirements
with notice in advance at any time during the season in order to
provide equality of performance.
4.2) Ballast
It is permissible to install one or more ballast to fulfill the
requirement of the minimum weight. The position and the
installation method of the ballast are free, but both the ballast
and the bodywork part to which the ballast is fixed must have
sufficient strength.
Article 5: Engine 5.1) Type and position of engine
An engine from another model of car can be mounted if it derives
from the homologated or registered vehicle of the same
manufacturer.
The mounting position, location and orientation of the engine
are free provided the engine is situated fore of the front bulkhead
or aft of the rear bulkhead.
5.2) Engine modifications 5.2.1) Cylinder capacity
Modifications to cylinder capacity are permitted.
5.2.2) Supercharging device Free.
5.2.3) Cylinder head and cylinder block
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Reinforcement of the head and block is permitted.
5.2.4) Crankshaft and connecting rods Free.
5.2.5) Bearings
Free provided that the original type of the bearing (plane
bearing, roller bearing, etc.) is maintained.
5.2.6) Cylinder head gasket
Free.
5.2.7) Camshaft and valves (including valve springs)
Modifications to camshaft position / number and changes to the
driving system are not permitted
however, the other elements are free. Only when variable valve
timing is installed to the original engine and its mechanism
remains
identical to that original one, it is permitted to use it.
5.2.8) Pistons, piston pins, and piston rings Free.
5.2.9) Flywheel Free.
5.2.10) Ignition system Free.
5.2.11) Lubricating system Free other than the restrictions
defined below. When viewed from above, the oil cooler must not
protrude from the vehicle perimeter. If the oil
cooler is installed outside the vehicle, it must be positioned
below the horizontal plane passing through the wheel rotational
center of the vehicle in running order.
5.3) Air intake system
Free other than the restrictions defined below. The use of water
injection devices, variable valve timing, variable inlet ports, and
air intake
adjustment devices is allowed only if these devices were part of
the original vehicle or the original engine.
The use of a variable intake trumpet is not permitted.
5.3.1.1) Air restrictor
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All cars must have either 1 or 2 air restrictor(s) made of metal
with a tube(s) having circular section(s) maintained for a minimum
length of 3mm. All air admitted to the engine must pass through the
air restrictor(s). When all the intake air is forced to stop
upstream of the air restrictor(s), engine must be immediately
stopped.
5.3.1.2) Air restrictor diameter
Air restrictor diameter must be maintained as specified in the
Appendix 2 of this Chapter. Air restrictor diameter must comply
with the prescribed value at all time during an event.
The JAF may change the air restrictor diameter requirements with
notice in advance at any time during the season in order to provide
equality of performance.
5.3.1.3) Supercharged engine
The air restrictor must be situated at a maximum of 50mm
upstream of the vertical plane passing through the most upstream
extremities of the supercharger wheel blade, otherwise in the
middle of an airtight and one piece cone of 7 degrees minimum,
which is fitted directly to the inlet of the housing.
If an air restrictor and the cone are installed as an integrated
part, such part must be joined to the housing side of the
supercharger without any gap.
The JAF may impose restrictions on supercharging pressure with
notice in advance in order to provide equality of performance.
Drawing 7-21
5.3.1.4) Normally aspirated engine It is obligatory to equip an
air box and the air restrictor must be installed to an air inlet of
the box. The air box must satisfy the following conditions: 1) It
must not exceed 1,000mm x 500m m x 500mm 2) Intake ducts in front
of air box are free provided the external appearance of the car is
not
changed. The internal structure and also the material of the air
box are free. 3) When all the intake air is forced to stop while
the engine is running, the engine must stop and
the air box and those intake ducts in front of it must have
sufficient rigidity not to be damaged or failed.
5.3.2) Air restrictor exemptions
Air restrictor
The housing of the supercharger
Integrated part
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Vehicles equipped with a naturally aspirated reciprocating
engine having a cubic capacity of up to 2,000cc where all the
intake air is delivered through a single aperture, no air
restrictor installation is required.
5.3.3) Intake temperature 5.3.3.1) Intercooler
Intercoolers for cooling the intake air including its mounting
position and piping are free. But their only function must be to
channel air. Apart from intercoolers, any device, system,
procedure, construction or designs which have the
purpose and/or effect decreasing the temperature of air supplied
for the engine are forbidden. 5.4) Cooling
Water radiators are free, as long as its function is identical
to the one installed to the original vehicle.
Water pumps are free. For the purpose of cooling the water
radiator, oil cooler and each engine part, only air is
permitted
and other cooling method by injection or spraying of any
substance other than air into them is prohibited.
Heat exchanger can be used. Flexible air ducts may be installed
in the engine compartment to cool auxiliary equipment of the
engine.
5.5) Exhaust system The exhaust system is free. However,
1) at least one catalytic unit must be installed through which
all exhaust gases should pass. The unit must be approved by JAF and
the application must be submitted no later than 2 months before the
competition in which the unit is used for the first time;
2) variable exhaust systems are not permitted. Exit of the
exhaust should be as follows for the cars with a lateral exhaust
exit: 1) Minimum height: the lowest point of the exit must retain
the minimum ground clearance without
fail. 2) Maximum height: the highest point of the exit must not
exceed the parallel plane passing 300mm
above the bottom surface of the flat bottom. 5.6) Rotary engines
5.6.1) Supercharging is not allowed for 3-rotor engines. 5.6.2)
3-rotor engines must be equipped with air restrictors specified in
the Appendix 2 of this Chapter. 5.6.3) On vehicles equipped with a
naturally aspirated rotary engine where all the intake air is
delivered
through a single aperture, no air restrictor installation is
required. 5.6.4) Type of rotary engine port
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Free.
Article 6: Lines and pumps, and fuel tanks
Free as long as Articles 6.1), 6.2) and 6.3) are observed. 6.1)
Fuel tanks
It is obligatory to install a safety fuel tank. It is obligatory
that a flexible joint be used for the junction of the fuel tank and
fuel filler neck,
which can allow bodywork deformation in some degree and avoid
any leakage of fuel.
6.1.1) Location of Fuel Tanks All safety fuel tanks must be
situated in the original position or between the front and rear
wheel center
lines (inside the wheelbase). They must conform to the following
conditions. 1) It must be situated behind the rear edge of the
front seat except when it is installed fore of the front
bulkhead. 2) It must be surrounded by an impact absorbing
structure of at least 10mm thick. 3) It is permitted to cut the
cockpit floor in order to install a safety fuel tank. 4) It must be
insulated by a rigid and non-flammable fire wall from driver and
the engine
compartment, which is made of the material defined by 3.3.5.2)
"Rear bulkhead" 3). For this purpose, the bulkhead defined under
Article 3.3.5) "Bodywork (monocoque structure) and bulkhead" or a
floor without openings may be regarded as a fire wall. The
container for the safety fuel tank is not considered to be a fire
wall. If the bulkhead extends vertically from the floor of the
vehicle to the ceiling, a window of the smallest possible area may
be installed to the bulkhead to permit vision to the rear of the
vehicle. The window must be made of laminated glass.
5) Leakage of the fuel must not be accumulated and careful
attention should be paid for it so as not to go into the
cockpit.
6) It must be surrounded by a rigid construction so that it is
not damaged even by a lateral impact. 6.1.2) The use of self
sealing breakaway valve for all fuel lines between the fuel tank
and the engine is
considered desirable. This valve must operate at less than 50%
of the load required to break the fuel line fitting or to pull it
out of the fuel tank.
6.1.3) Fuel supply system
It must not be installed in the cockpit and outside of the
bodywork. Except for the fore-mentioned condition, the system is
free.
6.1.4) Unless the tank fillers are connected directly to the
tank, it is recommended that a valve supplied by the tank
manufacturer be installed at the top of the tank. The valve should
permit sealing the fuel tank in the event of the filler being
knocked off during an accident.
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6.1.5) Position of the filler
1) Minimum height: The center of the filler must not be lower
than the plane passing through 595mm above the bottom surface of
the flat bottom.
2) The distance between the center of the filler and the edge of
the exhaust exit must be 1000mm or more in plain view.
Drawing 7-22 6.2) Fuel capacity
The maximum amount of fuel which may be carried on board is 100
liters. The JAF may reduce the total fuel tank capacity with notice
in advance.
6.3) Number of fuel tanks
Multiple fuel tanks may be used as long as the maximum capacity
of the tanks does not exceed that specified in Art. 6.2) "Fuel
capacity" above. However, only 1 collector tank is permitted.
6.4) Cooling of fuel
It is permissible to install cooling device to the fuel supply
piping mounted on the vehicle for the purpose of decreasing the
temperature of fuel. The only method allowed for cooling fuel is
air-cooled method by natural air stream.
Flat bottom
the center of the filler
Filler
Exhaustexit
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Article 7: Electrical Equipment 7.1) Battery
Only sealed batteries are permitted. Insulation to prevent
shorting must be installed. The battery may be mounted anywhere
except in the area of the driver's seat. There are no restrictions
on battery make and capacity.
7.2) Lighting
Indicators, by which the driver may recognize whether the
headlight and/or the direction, must be fitted.
7.2.1) Headlights
1) Headlights must remain in their original position. Their
configuration and function of the original vehicle must be
maintained. The main optical axis must be to the front. Brightness
(light intensity) must be at least equal to that of the original
vehicle's headlights so that the lightening can be recognized by
the drivers of the cars running in font and the officials around
the track. Right and left lights must not be illuminated by
turns.
2) Headlights must have yellow or amber colored covers. 3) If it
is not possible to install the same lighting unit(except luminous
valve) as that was installed on
the original vehicle, the diameter of the surface of headlight
lens must be at least 10cm. 4) It is authorized to alter a light
source for the purpose of increasing illumination (or luminous
intensity). 5) If the vehicle is originally equipped with
retractable headlights, the retracting mechanism may be
removed and modifications with transparent materials may be
carried out so as to lighten the front of the vehicle.
7.2.2) Other lights 7.2.2.1) Tail light and brake light
Tail light and brake light must have the same configuration as
those of the original vehicle. Brightness (light intensity) of
these lights must be equal to or greater than that of the
original
lights.
7.2.2.2) Direction indicators The lightening of indicators must
be recognized by the drivers of the cars running in
front/behind
and the officials around the track. The diameter of the
indicators' lens surface is required to be at least 30mm.
There is no restriction on side markers including its
removal.
7.2.2.3) Other lights Ducts can be connected to openings which
are created by removal of the original lights.
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7.2.3) Wiper It is permissible to change the front window wiper
construction. However at least one wiper must
be equipped and it must be able to be operated by the driver
seated and activated effectively at any time during an event.
Article 8: Transmission 8.1) Drive system
Changes in drive system are permitted regardless of the system
used in the original vehicle. Kinetic Energy Recovery System may be
used providing the system is submitted to JAF and
approved according to the "Supplementary regulation for Kinetic
Energy Recovery System". 8.2) Clutch
Free provided the conditions set out in the Article 2.1.2)
"Control function restrictions" are respected.
8.3) Transmission and transmission control lever
The gearbox must comprise a maximum of 6 ratios and a reverse
gear. Mounting position is free. Use of a paddle sift system is
authorized.
8.4) Final drive system and differential
Free provided the conditions set out in the Article 2.1.2)
"Control function restrictions" are respected.
The viscous clutch is permitted provided that it is not
controllable when the car is in motion. 8.5) Propeller shaft and
drive shaft
Free.
8.6) Cooling Only air cooling of the transmission is permitted.
Injection or spraying of any substance other than
air to cool the brakes is prohibited. Mounting of oil cooler is
free.
Article 9: Suspension and steering 9.1) Suspension type and
installation
Suspension type on the original vehicle may be freely modified
and altered. However, even if the suspension fixation point on
bodywork side is changed, the suspension must
work normally when the engine is dismounted.
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9.2) Anti-rollbar
There are no restrictions on anti-rollbar including their
installation brackets. Adjustment of anti-rollbar can be made
mechanically only by driver when the car is in motion.
This must not be adjustable by any other means than the said
method. 9.3) Axles
There are no restrictions on axles including spindles. They may
be changed into Center locking type.
9.4) Springs
There are no restrictions on springs including the addition of
supplementary springs provided the conditions set out in the
Article 2.1.2) "Control function restrictions" are respected.
9.5) Shock absorbers
There are no restrictions on shock absorbers provided the
conditions set out in the Article 2.1.2) "Control function
restrictions" are respected.
9.6) Suspension arms
All suspension arms must be made of metal. 9.7) Chromium
plating
Chromium plating of steel suspension arms is not permitted. 9.8)
Steering
Steering wheel, steering system (steering gearbox, link) and
steering wheel must be connected solely by mechanical means.
Power steering is permitted to use only if it is a single system
without a programmable control. Open type steering wheel is
forbidden. A quick release system must be installed on the
steering
wheel and its method must be of the type pulling a concentric
flange situated on the steering column. It is recommended to
install a steering column with an impact absorbing device.
Article 10: Brakes 10.1) Brake system
The brake system is free, provided the conditions set out in the
Article 2.1.2) "Control function restrictions" are respected.
However, there must be no sensors or devises other than a fluid
pressure sensor, a brake light switch and a proportional brake
valve on the lines between master cylinder and caliper.
Parking brake installation is optional.
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10.2) Brake calipers
A single caliper is allowed for each wheel. Each caliper may
have up to 6 pistons. The cross-section of each piston must be
cylindrical.
10.3) Brake cooling
Only air cooling of the brakes is permitted. Injection or
spraying of any substance to cool the brakes is prohibited.
However, the use of brake caliper cooling system by a liquid
circulation is permitted.
Air ducts for cooling the brakes may be installed. However,
these ducts must not change the bodywork configuration above the
bumper and not permit the aerodynamic effect beneath the vehicle
between the front and rear wheel center lines (within the
wheelbase).
There is no restriction on the number and size of air ducts used
to cool each brake assembly. Air ducts made of titanium are not
permitted. Other than this, there is no restriction on air duct
material.
10.4) Brake discs Maximum one brake disc made of ferrous
material per wheel is permitted.
Article 11: Wheels and tires 11.1) Dimensions 11.1.1) Complete
wheel maximum diameter and maximum width
Maximum diameter: 28 inches Maximum width: 14 inches However the
maximum width of a complete wheel may be more than 12 inches under
the
following conditions; 1) The material is restricted to aluminum;
2) The minimum weight is 10kg/wheel excluding balance weight and
including air valve.
11.2) Wheel material
Wheel material is free but they must be made from metallic.
Accessories of wheels are permissible only if they do not exceed
the maximum width of the
complete wheel and are secured by bolts etc. 11.3) Wheel
attachment
Wheel attachment is free, if a single center nut, a red or
dayglo orange safety spring or a device/system performing the same
function as the said spring must be installed to each wheel when
the car is in motion. The safety spring or the similar device
mentioned above must be installed after each wheel change.
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11.4) Pneumatic jack
Pneumatic jack installation is permitted. However, the
installation of a compressed air bottles to the vehicle is
prohibited.
Article 12: Safety equipments and devices All the regulations
concerning safety are completed by adding the following to the
Chapter 4 "Safety
regulations for homologated cars and registered vehicles" and
applied. 12.1) Safety belts
The wearing of two shoulder straps, one abdominal strap and two
straps between the legs is compulsory.
Safety belts must comply with FIA standards 8853/98. Each strap
of the safety belt must have its own fixation point on the
bodywork. Two abdominal
straps for right and left respectively can be prepared as long
as they have the same homologation numbers and the two abdominal
straps on one side may be attached together by one attachment point
on the body.
12.2) Rear view mirrors
It is permitted to remove an inside mirror or replace it with
any other system of equivalent efficiency, when the bulkhead
extends from the floor to the ceiling under the prescriptions
mentioned in 6.1.1), or when a partition window serves as a
bulkhead as defined under the Art.17 "Protection against fire" of
the Chapter 4 "Safety regulations for homologated cars and
registered vehicles", regardless of the provisions under Art.7
"Rear view" of the Chapter 4 "Safety regulations for homologated
cars and registered vehicles". However, in this case, the rear view
must be secured, and outside mirrors which have at least the same
size as those of the original vehicle must be mounted on the both
side of the outer surface of the bodywork.
12.3) Seats and Headrest
It is obligatory that FIA homologated competition seats
(Standards 8855-1999 or 8862-2009) which have a reinforcement part
around the drivers head padded with energy absorbing and non
flammable material be used.
The driver's seat can be moved towards the center of the car
unless it does not go beyond the longitudinal center line of the
car.
Headrest must be able to retain the driver's head wearing a
helmet and must not have it move rearward during acceleration. The
drivers head must not be caught between the headrest and rollover
bars. It is recommended that the distance between the sides of the
headrest should not exceed 400mm and that energy absorbing material
of minimum 20mm is fixed to the both sides.
12.4) Relation between seats, rollcage and lateral protection
structure
The following dimensions should be respected within the plane
perpendicular to the centerline of a
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car and to the surface of the flat bottom including the lowest
point of the seat at the center of it.(Drawing 7-23) However when
the seat has a sliding system, the position of slide can be
optional. 1) The distance between the center of the seat and
lateral roll bar should be 950mm or more. 2) Between the center of
seat and the lateral protection structure, horizontal distance
should not be
less than 250mm and the difference of their vertical height
should not be greater than 430mm.
Drawing 7-23
12.5) Relation between drivers helmet and roll cage
When a driver is seated in his normal driving position and looks
straight ahead, roll cage must not be existed within the range
shown in the Drawing 7-24 when seen from the side.
Drawing 7-24 12.6) Elements between the door and the driver's
seat
Between the door and the driver's seat, no mechanical components
may be installed other than side bars of the rollcage.
However, the impact absorbing structure, the knee pad and the
water-supply bottles are not considered as mechanical
components.
Flat bottom
The lowest point of the seat at the seats center
Side view of a car
The lowest point of the seat at the seats center
Cross section of lateral roll bar
Aria for lateral protection structure
Side view of a car
Line contacts with the highest point the drivers helmet when he
is seated in his normal driving position and looks straight ahead
and parallel to the flat bottom
Rollcage can not be exited within the meshedpart
Line contacts with the rearmost point the drivers helmet when he
is seated in his normal driving position and looks straight ahead
and perpendicular to the flat bottom
Flat bottom
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12.7) Frontal (back) protection structure
For the purpose of installing a crushable structure in the front
of car, modifications are permitted. But these changes must be
limited to the smallest possible area on the side rails situated
fore of the frontal edge of the front complete wheels.
When a tubular structure defined under the Article
3.3.6)"Bodywork structure fore of the front bulkhead and hind of
the rear bulkhead" is installed, a crushable structure which
satisfies the following requirements must be installed: 1) The
structure mounting position
Forward of the frontal tubular frame. Mounting the structure to
the rear part of the frame is not obligatory (optional).
2) Impact resistance The average deceleration of the car must be
less than 25G and must not exceed the maximum deceleration 60G for
more than 3ms when a frontal impact test is carried out. For this
test the car's weight must be 1,500kg. The car shall collide
head-on (full overlap) by at a velocity of 12metre/sec.
3) Dynamic crash test A unit of crushable structure on a trolley
is subjected to a dynamic crash test. A certification with a
signature of the person in charge of the testing laboratory must be
issued and its copy must be submitted to JAF. It is not necessary
to present a copy of the verification every year unless the vehicle
type and its
design remain the same. 12.8) Lateral protection structure
1) In order to absorb impact, inside the door of driver's side
should be either filled with non-flammable shock absorbing material
and/or made up of crushable structure except when a rollcage
structure admitted by Art.258.15.15.1 of the Appendix J(Drawing
258-4) is constructed. In that exceptional case it is recommended
to perform certain measures such as increasing the thickness of the
door outer panel.
2) If the door of the driver's side remains the same as that of
the original vehicle, original energy absorbing structure located
inside of the door may not be removed and the additional bar of
which material and dimensions are the same as those of the rollbar
specified by the prescriptions of Art.253.8.2.2.5.2 of the Appendix
J must be mounted.
3) Furthermore, if the material of the door was changed, the
door bar specified in Art.253.8.2.2.5.2 of the Appendix J must be
added. However, if the door bar is not comprised of JAF/FIA
rollcage, it is not obligatory to comply with above 2) and the
relevant prescriptions.
4) It is permitted to install an impact absorbing device between
the door of driver's side and the rollcage.
12.9) Cockpit exit time
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When the driver escapes from the cockpit in an emergency from
his normal driving posit