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Super GT Japanese Grand Touring Series organized by JAF; inluding JGTC, and JTCC
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Old 01-22-2006, 04:56 PM   #1
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Question JGTC rules ??

recently I start watching the JGTC and I like it
but can anyone expline to me the JGTC rules .... all I know that they are not alowed to pass 500hp and 300hp. but is there any other rules !
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Old 01-28-2006, 09:13 PM   #2
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Re: JGTC rules ??

Crap there was a superstreet or some kind of magazine like that had the rules in it i'll look and see if i can find it later. I know the engine they use has to be based off a production engine an i think i read there was a limit to how wide and low the car can be. Also i know the penalize for forced induction i think by addin a restrictor to limit airflow.
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Old 03-06-2006, 07:04 PM   #3
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Re: JGTC rules ??

It was superstreet, they did a big spread on all the cars running in either the 04' or 05' seasons. I'll try to find it.
Black 1997 3000GT

Originally Posted by Igovert500
[01:05] Igovert500: scrwe his method
[01:05] Igovert500: too much crap
[01:06] Igovert500: i just jam a garden hose in there
[01:06] Igovert500: and put it on high flow
[01:06] Igovert500: go the opposite direction too
[01:06] Igovert500: so it clears out more shit
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Old 03-06-2006, 09:09 PM   #4
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Re: JGTC rules ??

you people depress me....oh well I will give in. here you go 2 posts of joy

Series Titles
SUPER GT consists of 2 categories of car: Category 1(GT500); and Category 2 (GT300). Each category comprising of two titles of Series: one for drivers (pair), one for teams.


Eligible cars
Cars running in the SUPER GT must conform to the following technical regulations of SUPER GT set by the GT-A.
1. JAF-GT Cars :

Cars conforming to the 2005 JAF National Technical Regulations for "Grand Touring Cars (JAF-GT)".

2. Cars approved exceptionally by the GT-A as follows:

(1) JAF-GT cars that participated in the 2004 JGTC,
(2) FIA GT homologated cars,
(3) Le Mans GT cars,
(4) SCCA GT cars,
(5) Grand-American GT cars,
(6) DTM 2000 cars,
(7) Other cars approved exceptionally by the GT-A


Cars participating in each category are as follows:
Category 1 (GT500): JAF-GT cars that comply with Class 1 in the JAF National Technical Regulations, and cars approved exceptionally by the GT-A.
Category 2 (GT300): JAF-GT cars that comply with Class 2 in the JAF National Technical Regulations, and cars approved exceptionally by the GT-A.

* Reserve cars are not permitted.


A vehicle must be driven by 2 drivers during the race. The total driving time per driver may not exceed 2 / 3 of any race distance. Throughout the Event, drivers are permitted to drive only one vehicle.
Licenses : All competing drivers must hold current and valid International licenses (minimum requirement: grade C license), as issued by their respective ASN(s).


A maximum of 3 sets of dry-weather tires per car may be used for all running from the beginning of the qualifying practice session to the start of the race for any given event. Of the 3 sets, one will be chosen by lottery, which will be conducted by the organizers of the event, as the set on which competitors must start the race on. To start the race on tires other than the set chosen by lottery is not permitted under any reason (except in circumstances such as the track being declared wet for the start of the event).
Practice session:

Excluding the set chosen by lottery, the rest of the sets of tires can be used freely. It is permitted to use the other 2 sets of tires in any combination regardless of the L/R marking For the qualifying and free practice sessions, the use of tires other than the sets mentioned above is prohibited under any circumstances (except in cases where the track has been declared wet by the Clerk of the Course).

Wet-weather tires:

Except for during the race, the use of wet-weather tires is permitted only when the Clerk of the Course declares wet conditions.
Tire manufacturers supplying wet-weather tires to competitors have to register the groove pattern to be used to the JAF at least one week prior to the very first Event which the wet -weather tires are used.

Use of any external device to heat or warm the tires during the Events is strictly forbidden.

*Under a Gentleman's agreement between the competing tire manufactures and the GT-A, number of tires which can be used during the 3 days of the race-weekend is limited up to 13 sets per car.


Fuel used for the Events must be marketed un-leaded gasoline with a maximum of 102RON.
Only the Organizer can designate the fuel to be used in championship events. Mixing of the designated fuel or including the introduction of any additives (gas, liquid, or solid) except for air, is prohibited.


Practice Sessions (Free Practice, Qualifying, Practice etc.,)
Practice sessions are composed of the qualifying practice sessions and the free practice session on race day.
2 qualifying sessions of 60 minutes each are set by the organizer. A minimum 3 hour interval is compulsory between each qualifying practice session. The qualifying sessions will be conducted according to the following procedure of either (1) or (2):
(1) The qualifying practice session of 60 minutes will be divided into three sections. The first session will start in order of GT500, GT300, and then both categories combined, the second session will start with both categories combined, GT300 and then GT500 for 20 minutes each section.
(2) The qualifying practice session of 60 minutes will be divided into three sections. The first session will start in order of both categories combined, GT500, GT300, and the second session of 60 minutes will be divided into two sections and each class is to use 30 minutes severally. The procedure shall be stated on a sporting regulation. As for Super lap qualifying session, refer to a separate section.
>> Super Lap qualifying session

*However, in the case of 'force meajeure', the discretion of the Stewards of the Meeting takes precedence.
*To qualify on the grid, drivers must achieve a lap time at least equal to 107% of the average time of the 3 best laps achieved by the top 3 cars in each class.
*Cars returning to the pit with the assistance of the marshals during the qualifying practice sessions or its interruption are not allowed to run for the remained of the session.
*The final lap time measured after the checkered flag or the run-on-the-track board is shown will be effective.
*If 2 or more cars achieve the same qualifying time their order will be determined by the order in which they achieved it.
*When the number of cars which achieved the Qualifying Time is less than that of cars permitted to start the race stated in the Supplementary Regulations, the entrant for the driver who could not achieve the Qualifying Time may submit a petition to the Stewards of the Meeting for starting the race. The car's position on the starting grid is to be at the very back of the category concerned.


Starting grid
The starting grid will be set in a 1 by 1 staggered formation, according to the best lap times attained by each car during the qualifying sessions. However, the GT500 category will always be placed in front of the GT300 category regardless of the time attained during these qualifying sessions. The 1 by 1 staggered formation is applicable only to the stationary position of the cars (ie: grid positions before the warm-up lap). A 2 by 2 formation is permitted for the rolling start of each event.
Pole position is given to the car which set the fastest lap time in the qualifying practice session, and the said driver cannot choose any other position.
Pole position and grid of the top GT300 car will always be on the inner side of the track towards the first corner.

*If one or more cars are withdrawn before the final starting grid is decided, the grid will be closed up accordingly.
*After the qualifying practice sessions, if the pole position car cannot start the race, that grid position grid will be left open.
*After the final starting grid is published, if any car cannot proceed to their grid position, that position will be left open and other cars will remain in their own grid positions.


Rolling Start:

The type of start adopted for each event will be a 'rolling' start.

Start from the pits:

The pit exit will close as the signal light turns red 37 min. before the start of the formation lap. Any car which is still in the pits after this time will be permitted to start from the pits. Those cars will join the race as the signal at the pit exit turns green after the whole field has passed the pit exit following the start of the race.

Work on cars on the grid:

Work on cars on the grid will be permitted until the "5 min. to start" signboard is shown. Refueling and replenishing of all kinds of oil is prohibited.

Starting procedure:

"5 min. to start" signboard: Countdown starts. Entry to the grid will be closed. All works on car on the grid will be prohibited. A car that cannot reach the grid by then must start from the rearmost grid of each category. However, when instructed by the marshals, they will return to the pits to start from there.
"3 min. to start" signboard: Everyone excluding the drivers and the marshals shall evacuate the track.
"1min. to start" signboard: An engine is started by the driver in the cars.
"30 second to start": After this sign, a green flag will be waved in front of the grid, at the same time all cars will start the orderly formation lap led by the organizer's official leading car. During the formation lap, it is strictly prohibited to practice start, to break the formation or to overtake, and the formation must be kept as tight as possible. Until instructed by the organizer a formation of single file is permitted, but after instruction, the formation is set to double file and the cars must not exceed the side line of the car in front. A penalty will be imposed for violation.

Cars unable to start the formation lap

If a car does not start at the formation lap, the driver is to open the window on the driver side, raise his hand, and signal to the marshal. The grid marshal will wave a yellow flag.
After all other cars leave the grid, the marshals only may push the car to start. This car may join the formation lap but may not overtake the other cars.
The cars which couldn't start the formation lap or keep the position of the grid order in the middle of the formation lap, may not overtake the other cars and must take the rearmost position.


The red light of the signal light on the start line is turned on at the moment the formation lap starts and yellow flags will be displayed at every post. The starting signal will be given by means of starting light (green light) activated under the control of the Clerk of the Course. The race will start as the red light on the start line turns to green, but the cars must not overtake each other until they cross the start line.

Speed of the official lead car

The speed of the official leading car leading the field is kept at approx. 80 km/h. The organizer's official leading car will pull off at the end of the formation lap. The cars will continue on their own with the pole position leading at a minimum speed limit of 70 km/h and a maximum of 90 km/h. The leading car of GT300 is not permitted to exceed 90km/h until it passes the start line.

Start Delayed

If a problem arises during the formation lap, the red light will stay on. Yellow flags will be displayed at all the observation posts. The cars, with the pole position leading, will complete a new formation lap (the speed of all the cars will be kept). They will be joined and led by the official leading car and will continue for another formation lap.
If the start of the race is imminent and, in the opinion of the Clerk of the Course, the volume of water on the track is such that it cannot be negotiated safely even on wet-weather tyres, may delay the start.

*Any breach of the starting procedure may result in exclusion of the car and driver concerned from the Event.


Safety Car
A car equipped with 3 yellow lights on the roof. According to the provisions set in the I.S.C. Appendix H, a safety car may be brought in to the track when necessary.
Details on applicable regulation will be provided in separate rules.


Finish and Race Stoppage

The end-of-race signal (checkered flag ) will be given as soon as the leading car has covered the full race distance.

Checkered flag mishap

Should for any reason, carelessness or others, the checkered flag be given before the leading car completes the scheduled number of laps, the race will be deemed to have finished when the leading car last crossed the line before the signal was given.
Should the checkered flag be delayed due to carelessness, the final classification will be determined according to the order of cars when the scheduled number of laps was completed.

Race Stoppage:

When usual safe condition is not kept, a race is stopped by red flag. When the signal is given to stop, all cars shall immediately stop competition and follow the instruction of the marshals under a speed slow enough to be able to stop at any time to proceed to the locations stated as follows:

Restarting a race

If a race is stopped, the Clerk of the Course can resume the race under discussion with the Stewards of the Meeting under following conditions.
The race leader completed less than two full laps: the original start shall be deemed null and void. The length of the restarted will be the full original race distance.
The race leader completed two or more full laps but less than 75% of the race distance: the race is considered to be divided into two parts, and classification will be done as to add the laps covered by each car at the 1st and 2nd parts. If cars are on the same number of laps, classification will be decided based on the race order at the second part.
The length of the second part will be three laps less than the original race distance less the number of classified laps completed by the leader before the signal to stop was given. The grid for the re-started race will be arranged in the race order at the end of the lap two laps prior to that during which the signal to stop was given. The race leader completed more than 75% of the race distance: the race will be deemed to have finished when the leading car crossed the line at the end of the lap two laps prior to that during which the signal to stop was given.


Pit Assistance

At least one refueling is compulsory during the race. Cooling of the fuel used or its supply device is prohibited in any method or device. The engine must be stopped during refueling. A driver can remain in his car during refueling. A competitor must ensure that one or more assistant with an extinguisher with the 5 kg or more contained ready to work is beside the car throughout all refueling operations. The refueling personnel and the assistant with an extinguisher must wear fireproof suits, gloves, full faced helmets and balaclavas. It is permitted to refuel after jacked up, but not to jack up during refueling.
All work is prohibited during refueling except the following: Changing of drivers, fastening of seat belts, setting timing transponder, making connections of radio for drivers, drink bottles, and driver cooling suits, and changing ice in the ice box.

Turning off the engine

During any stop in the pits, the engine must be turned off. For any tuning or regulating, the engine may be started with the help of an auxiliary source of energy. However, when the car goes to rejoin the race, the engine must be started by the driver from his seat, using only those means available on board with the four wheels touching on the ground.

Prohibition of reverse gear

The use of the reverse gear in the pits or the pit area is strictly prohibited.
If a car has passed its pit, the car can only be pushed back by its team personnel.


During the race, it is forbidden to change cylinder blocks (crankshaft case and cylinders) or chassis. Failure to comply will result in penalty of exclusion.

Number of mechanics

Excluding tire manufacturers' technicians and fire extinguisher-holding safety personnel, a maximum of 5 team mechanics per participating car may work on the car in a pit stop. These 5 mechanics must wear fireproof suits and fireproof gloves throughout the entire pit stop.
Apart from work concerning refueling, a maximum of 3 team mechanics per car can work on the car during refueling. The driver is not included in this number. Cleaning of the windscreen and changing of the ice in the icebox is considered to be work on the car.

Tire changing:

A maximum of 2 team mechanics per car can change the tires on a given car in the pit stop. Changing the member of the 5 mechanics while they are working on a car during a pit stop is not permitted. 2 mechanics who are in charge of changing tires must pick up each tire placed flat on the ground, and fit it to the car without receiving any assistance from others. After removal from the car, the 2 tire-changing mechanics must place the tires flat on the ground without any assistance. It is not permitted for these 2 tire-changing personnel to hand over or throw the tires to others.

*Changing tires during pit stops is not obligatory.


Handicap Weight System (Special Adjustment of Performance)
Demotion of Performance:

Qualifying and fastest laps in races: In each category, a handicap weight of 10kg will be compulsorily allocated at the subsequent race to cars qualifying in the top 3 places, and setting top 3 fastest laps, in a given race. This handicap weight shall be accumulated - without any upper limit throughout the duration of the season - and shall not be reduced except in cases falling into the "Promotion of Performance" clause as stated elsewhere in these regulations. Race: In each category, a handicap weight will be compulsorily allocated at the subsequent race to cars finishing in the top 3 places in the preceding race, according to the following scale:

Handicap Weight System
Race 1st 2nd 3rd 4th 5th 6th 7th or
GT500 +50kg +30kg +20kg +10kg - -10kg -20kg
GT300 +30kg +20kg +10kg +5kg - -5kg -15kg
Qualifying 1st 2nd 3rd

Each Category +10kg +10kg +10kg
Fastest lap in race 1st 2nd 3rd
Each Category +10kg +10kg +10kg
> Air restrictor and minimum weight

Maximum weight loaded:

According to the above handicap weight the maximum weight to be loaded on cars will be 120kg for GT500 and 100kg for GT300 cars. Any excessive handicap weight above this shall be exempt from loading, but shall be accumulated numerically, and reduction will not be applied to the actual weight on the car, but to this numerical accumulation. Handicap weights as mentioned above will not be accumulated if the model of the car is changed or if team and drivers are changed simultaneously.

Weight reduction amounts are as follows:

20kg for GT500 class machines, 15kg for GT300 class machines. Maximum load of weight on cars:

Position of handicap weight:

The weight of the installation device used to load the weight will be included within the total handicap weight. Handicap weights must be made from lead plates. Plates up to 50kg must be attached to the passenger's seat attachment. Weights over the 50kg level can be attached to any location within the car without restriction. All cars with weight handicaps imposed must attach weight handicap sign stickers where designated.

Promotion of Performance:

In accordance to the results of the preceding race, cars may broaden the diameter of their air restrictors when entering the succeeding event, restricted to the criteria mentioned below. This measure however, shall not be applied to "a car specially approved by the GT-A." Special adjustment of performance, equivalent to this measure, shall be applied instead. In addition, adjustment will not be made on cars which performance have been demoted by weight handicap during the Series.

A. Cars slower than the standard time determined by adding 1 second to the average best lap time of the top 6 cars of each category in the qualifying practice: 1 point.
B. Cars slower than the standard time determined by adding 0.5 seconds to the average of the top 6 best lap times of the race: 1 point.
C. Cars ranked in 7th position or below in the Championship standings in each category at the end of each race: 1 point.
According to criteria A to C above, any car whose accumulated points totals 3 may change their air restrictor diameter without having to change the minimum weight of the car. In the subsequent event, the car is permitted to run with the air restrictor diameter of a car with a 50kg weight handicap increase in the same engine division.
However, this measure shall be limited to use of the air restrictor diameter at a minimum weight increase of 100kg in the same engine division.
In the case where a car which has already applied the Promotion of Performance measure and meets 2 of the criteria, it is allowed to continue to apply until the car meets criteria A. In the case where the car has gained 2 levels of the Promotion of Performance measure, the car must revert back to the condition for cars with the 50kg increase.

*In the case where a car, which is applied a handicap weight becomes the object of the Promotion of Performance measure, the measure is not applied. However, the handicap weights will be reduced by 10kg from its cumulative total weights up to 2 of the criteria.
*If car model, engine model or engine displacement volume of a car to which the measures in these provisions have already been applied are changed, they will be cancelled.


Series Points
The points given to drivers and teams on each event sanctioned as the Series is as follows.
Series Points
Race 1st 2nd 3rd 4th 5th 6th 7th 8th 9th 10th
Points 20 15 12 8 6 5 4 3 2 1
Qualifying 1st 2nd 3rd
Fastest lap in race 1st 2nd 3rd
Points 2 1 1 Points 1 1 1

*The Series points will be given to any driver who shall drive only one car per event and complete at least 30 % (rounded down to the nearest whole number) of the laps covered by the car.
*If a driver participates in the Series with different cars, he is able to add up the points throughout the season on condition that those belong to the same category as his original.
*In each category, points will be awarded to teams according to the order of their cars in the qualifying practice sessions and the race, but should other cars of the same team finish the race in the positions to which the points will be awarded, only points for the highest-scoring cars will be taken into consideration.
*If a team participates in the Championship with different cars, said team is able to accumulate points throughout the season on condition that the competing cars belong to the same category as its original car.
*Points given to drivers and teams according to qualifying order and race lap time are not applicable to the last race of season.


Penalties are applied to any breach of the regulations or for disobedience to the instruction of officials. Penalties to breaches of the regulations during the race are as follows:
The stewards may impose any one of 2 time penalties during the race :
Drive-through penalty:

The driver must enter the pit lane and rejoin the race from the pit exit without stopping in the pits.

Penalty stop:

The driver must enter the pit lane, stop at the penalty stop area for the time penalized and then rejoin the race from the pit exit. He/she is not allowed to stop at his/her pit. It is not necessary to stop the engine in the penalty area.

Notification of penalties:

An announcement to the pit will be made as soon as the decision regarding the breach is confirmed, and a signboard showing the confirmed penalty, the black flag and a black board with the car number will be shown at the control line. If the announcement can not be made within the required time, additional time, equivalent to the penalty, shall be added to the elapsed time of the car concerned.


False start: Drive-through penalty
Disobeying yellow flag: Penalty stop 10 sec. or more
Any breach during pit assistance: Drive-through penalty
Speeding in the pit lane: Drive-through penalty
Any breach of driving conduct: Drive-through penalty or penalty stop 10 sec. or more.
Driving conduct more serious or unethical than above: penalty stop, 30 seconds.


Any cars /drivers who fail to heed notification of the above sporting violations within 3 laps of notification will be excluded from the race. If one of the drivers in a given car is excluded, the other driver of the same car will also be automatically excluded from the race concerned. The same refers to the car as well.
Stewards of the meetings may impose penalties such as penalty fine, point reduction, exclusion from the race in addition to time penalty.

Driving Moral hazard

Drivers must observe the Appendix L of the FIA International Sporting Code Chap. 4, "Code of Driving Conduct On Circuit". Any driver who is judged as he conducts a "dangerous driving" as a breach to the provisions will be strictly punished by the Stewards of the Meeting. In order to maintain a code of driving conduct, the GT-A shall lay down and apply the GT-A moral hazard system.

*Any protests and/or appeals against the above penalties will not be heard.


Race numbers for series champions
The team to which the reigning GT500 class champion belongs in the current season, may use race number "1". As for the GT300 class, the title-winning team's number shall be "0". If the concerned teams do not use these numbers, they shall be omitted.


Revision of Sporting Regulations
The GT-A may alter these Regulations at any time during the season.


Super Lap qualifying session
When the Super Lap (SL) qualifying session is adopted following Art.25(2) of the SUPER GT Sporting regulations, the organizer must determine the correct procedures in the supplemental regulations of the event. The reason is that the SL qualifying may be changed according to the circumstances and convenience of the host circuit. Following is a case of the SL qualifying which was adopted for Round 2 of the 2005 SUPER GT Series.

First Qualifying Session
- The qualifying practice session of 60 minutes will be divided into three sections of 20 minutes each. The order of the session is as follows: GT500, GT300, both classes combined .
- The top ten cars from each class will be able to take part in the SL, held in the second qualifying session.
- Cars in which one of the two drivers fails to achieve the minimum qualifying time will not be able to take part in the SL. Second Qualifying Session
- Prior to the SL session, a period of 15 minutes track time for both the GT500 and GT300 classes will be carried out.
- In these 15-minute sessions, the top two cars from each class will be able to take part in the SL. This in addition to the cars already selected for the SL. Refusing to run in the SL is subject to penalty.

- Cars not selected for the SL will be given grid positions from 13th place in class, in descending order according to times achieved in the first qualifying session.
- In the case where both drivers do not achieve the minimum qualifying time, the car will not be qualified.

Super Lap
- The SL will be contested by 12 cars from each class, with starting positions - from pole position to 12th place - determined by the fastest lap time achieved by each car.
- The SL session will start with the GT300 class, followed by GT500. Either of the two drivers in a competing car may attempt the SL.
- The SL session will be carried out with competitors running in pairs. The session starts with cars selected for the SL in the second qualifying session first; followed by cars selected in the first session. Cars run in ascending order, from slowest to fastest.
- The order of the two cars attempting the SL at the same time is; the faster car from qualifying goes out on track first.
- In the case where one of the two cars is unable to go out on track at the green light, this car will be allowed to go out on track after the other car has passed the main straight line. However, the following lap shall count as the timed lap for the car.
- The timed lap for the SL is only the third of the three laps run. The car must have its lights on during the timed lap.
- If a car cannot go out on track or stops on track due to a spin for example, timing will be stopped. The car's starting grid position will then be set after all other participating cars in SL have run, in accordance to their position from the first qualifying session.
- Cars that fall victim to Red or Yellow flags caused by other cars during the timed lap will be given another chance to attempt their timed lap.
240sx, soon to be S13.5, future mods are wheels and hopefully paint and the rest of my conversion.

(96 eclipse RS 5-speed, magnaflow exhaust,chrome headers,cold air intake,denso iridium sparkplugs,new kumho tires )******EDIT totalled car now*******
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Old 03-06-2006, 09:10 PM   #5
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Re: JGTC rules ??

and finally the cars.......

Original Vehicle
Definition Grand Touring Car:

Automobile having at least 2 seats and one door on each side respectively for getting in and out of the vehicle.

Vehicle type eligibility:

Cars must be homologated to FIA Group N, A, N-GT, GT2, JAF Production Touring Cars or Special Touring Cars, or otherwise be registered with JAF as registered vehicles.


Material restrictions
Composite materials (Including carbon and kevlar) are permitted in the relevant parts or areas if authorized in the regulations, or used as standard on the original car and original engine.
Titanium and ceramics:

Apart from connecting rods, intake and exhaust valves, valve retainers, heat shields, brake caliper pistons and superchargers, titanium and ceramic materials can be used on specific areas of the car, but only if these materials are used as standard on the original vehicle and engine.

Control function restrictions:

Any automatic or electronic chassis control system or function is forbidden, even if standard on the original vehicle. A simple open-loop electrical switch activated by the driver acting on a system is not considered to be an electronically controlled system.


Type and position of engine:

An engine which is produced by original manufacture and is legal for road use, and admitted by FIA and/or JAF can be mounted.
The mounting position, location and orientation of the engine are without restriction provided the engine is situated within the engine compartment of the original vehicle.

Engine modifications:

Modifications to cylinder capacity are permitted. Supercharging devices are also allowed. Reinforcement of cylinder head and cylinder block is permitted. Crankshaft and connecting rods modifications are unrestricted. Modifications to camshaft position/number and changes to the driving system are not permitted. Intercoolers for cooling the intake air including its mounting position and piping are unrestricted. The exhaust system is also without restriction. However, variable exhaust systems are not permitted.
Supercharging is not allowed for 20B (3-rotor) engines mounted onto GT300 vehicles.


Air restrictor and minimum weight
All cars must have either 1 or 2 air restrictor(s) made of metal with parallel hole(s) having circular section(s) maintained with a minimum distance of 3mm. All air feeding the engine must pass through the air restrictor(s). When all intake air is forced to stop upstream of the air restrictor(s), the engine must stall immediately.

Air restrictor exemptions:

On Class 2 (GT300) vehicles equipped with a naturally aspirated reciprocating engine up to 2000cc where all the intake air is delivered through a single aperture, no air restrictor installation is required.
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. However, GT300 vehicles equipped with rotary engines having 3 or more rotors require air restrictor installation.

Minimum vehicle weight and air restrictors:

The minimum weights shown in the table below are genuine minimum weights on the car in running order, which include all lubricating oil and cooling water filled and exclude the weight of fuel and the driver.
During the Event, the vehicle must maintain its minimum weight at all times.
Since the weight of handicap ballast and its installation device are calculated into the imposed weight, they cannot be used as elements to satisfy minimum weight requirements.

> Air restrictor and minimum weight



Except for modifications as permitted by the regulations, all bodywork dimensions and shape must remain original, and must be in accordance with the data shown on the homologation forms and documents of the registered vehicle. Ground clearance is measured from every direction of the complete vehicle perimeter and must be at least 50mm from the ground. Any and all suspended parts cannot be situated below this height. Front and rear overhang as well as wheelbase dimensions must be identical to those of the original vehicle. However, cars having an overhang of less than 900mm are allowed to extend the overhang by a maximum of 80mm, but never to exceed 900mm.

Windshield & Windows:

The front windshield must be in accordance with the rules under "Safety regulations for homologated cars and registered vehicles" in the JAF regulations. The front windshield glass may be replaced with polycarbonate of a thickness greater than 6mm and which permits the cockpit interior to be visible, provided the same installation position and shape as the original glass is maintained.

Changes in bodywork materials:

Composite materials and light metals may be substituted for front and rear bumper, fender, door, bonnet, rear hatch gate and boot-lid components provided that these substitutions maintain enough structural strength and do not result in configurative changes. Louvers, ribbing or lips etc. may be installed, if they do not significantly alter the external appearance of the vehicle (maximum protrusion allowed is 20mm).

Bodywork (monocoque structure) and bulkhead:

Bulkhead and cockpit areas must not differ from the original vehicle specifications (monocoque structure), and the bulkhead must not be modified except as permitted by the regulations. However, modifications to the bulkhead for reinforcement purposes are permitted.
Further, openings may be made for the purpose of connecting the tubular structure defined under the regulations below to the rollcage.
Bodywork structure fore of the front bulkhead and hind of the rear bulkhead:
Main structure (structural framework) situated fore of the front bulkhead and hind of the rear bulkhead may be cut and replaced by a tubular structure that is connected to the rollcage. In this case, it is obligatory to install a crushable structure defined under the regulations.


On each side of the car, fender dimensions may be extended (increased in width) up to 5cm over the width of the original vehicle, but the maximum width must not exceed 200cm.
The front part of the front fender and rear part of the rear fender must fit within the area defined under the regulations as viewed from above.

Hard tops for open-top cars:

Hard tops may be installed for open-top cars. But the hard top must maintain its configuration and be similar to the original. Use of material is unrestricted.


Aerodynamic device
Front aerodynamic device:

Front bumper may be integrated into front aerodynamic device in its construction. The demarcation between the integrated bumper and aerodynamic device is determined by the horizontal plane passing through the center of the wheel rotational axle of the car in running order(all the cars presented at the scrutineering ). The height of the extended plane is regarded as the lowermost limit of the bumper and the uppermost limit of the aerodynamic device.
Front aerodynamic device may be installed below the horizontal plane and forward of the vertical plane passing through the front wheel centerline of the car in running order. 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. There are no restrictions on Front aerodynamic materials devices.

Rear aerodynamic device:

It is permitted to fit either a rear air spoiler or a rear wing. The device on the original vehicle may be changed or removed. The wing must comprise no more than one aerofoil section and shall be framed in a rectangle, the dimensions of which are not to exceed: 40cm~15cm (including gurney-flaps, excluding supports and end plates). Its height must not exceed the highest point of the transparent part of the front windshield (including sun shield etc.,). Its width must not exceed the maximum width of the original vehicle (including supports and end plates). It must be placed within the perimeter of the car when viewed from above.

Diffuser (aerodynamic device mounted to the underside the rear floor):

It is permitted to add a completely flat inclined panel without openings. Inclined panel must be placed between the vertical planes, one passing through the rear edge of the flat bottom (a vertical plane passing through the rear wheel centerline) and one passing through the rearmost point of the bodywork. Maximum width of the panel is 1300mm and it shall be symmetrical in relation to the longitudinal axis of the car. No part of the panel may be situated more than 150mm above the flat bottom. If there is a gap between the inclined panel and the bodywork, it must be closed by a panel (shielding) vertical to the ground.

Flat bottom:

It is obligatory to install a flat bottom over the entire length of the car as viewed from underneath excluding wheel the housing and outer rear view mirrors. Between the front and rear wheel centerlines, the underbody of the car shall be securely fitted to a solid structure which is flat, impervious and rigid under all circumstances. The flat bottom shall not have an aerodynamic effect under any circumstance. No air stream may pass between the floor of the cockpit and the flat bottom. It is permitted to have a radius of maximum 25mm upwardly at the perimetric edge of the flat bottom.

Side skirts:

Side skirts are permitted below the horizontal plane passing through the centerline of the front and rear wheels of the car in running order, within the area (width) extended by the maximum vehicle width. The front/rear edge and the lateral edges must have a radius of more than 5mm. The outer surface of the side skirts may not enter the inside of the outer surface of the original vehicle. Furthermore, they must be connected to the flat bottom without any openings or gaps, and must also be connected to the front/rear fenders. There are no restrictions on side skirts materials.


Suspension type on the original vehicle may be freely modified and altered. However, if the suspension mounting points on the chassis/monocoque are modified, the suspension must still work normally when the engine has been dismounted. All suspension arms must be made of metallic materials. Spring and shock-absorber are free of restriction.
Adjustment of anti-rollbars can be made mechanically only by the driver, and only when the car is in motion. Anti-rollbar adjustment by any other means is not permitted when the car is in motion.


Steering systems (steering gearbox, link) and steering wheel must all be connected solely by mechanical means. Power steering is permitted only if it is a single system without a programmable control.


Drive train and transmission
Types of final drive:

Changes in types of final drive are permitted regardless of the system used in the original vehicle.

Gearbox, final drive system and differential:

The gearbox must comprise a maximum of six ratios and a reverse gear. Mounting position is unrestricted.
Gear shift lever and gearbox must be connected mechanically and no mechanical structure other than this can provide any shifting capability.
There are no restrictions on the shaft between the final drive system and the transmission, as well as on the drive shaft. Modifications to the transaxle which unifies the differential are also permitted. Viscous clutches are permitted provided that they are not controllable when the car is in motion. Mounting of oil radiator is unrestricted.


Brake systems
Brake calipers:

A single caliper is allowed for each wheel. Each caliper may have up to six pistons.The cross-section of each piston must be circular.

Brake disks:

Maximum of one brake disc made of ferrous material per wheel is authorized.

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 systems by liquid circulation is permitted.


Wheels and tires
Complete wheel maximum width

Class 1 (GT500): 14 inches / Class 2 (GT300): 12 inches

Complete wheel maximum diameter

28 inches (GT500 and GT300)

Wheel material:

Wheel material is unrestricted but wheels must be made from metallic materials.

Pneumatic jacks:

Pneumatic jack installation is permitted. However, the installation of compressed air bottles in the vehicle is prohibited.


Fuel tanks and Fuel supply system
Fuel tanks:

It is obligatory to install a safety fuel tank. All safety fuel tanks must be placed in the original location, in the luggage compartment, between the front and rear wheel center lines (inside the wheelbase) or extend between the luggage compartment and the wheelbase. It must be situated behind the rear edge of the front seat. The fuel tanks must be surrounded by an impact absorbing structure of at least 10mm thickness and insulated by a rigid and non-flammable bulkhead from the driver and the engine compartment.

Fuel capacity:

The maximum amount of fuel permitted on board is 100 liters


Electrical Equipment

Headlights must remain in their original position. Their configuration and function as on 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 lights' appearance and configuration can be recognized by drivers running in front of said vehicle, and by officials around the track. It is authorized to alter a light source for the purpose of increasing illumination (or luminous intensity). If the vehicle is originally equipped with retractable headlights, the retracting mechanism may be removed and modifications with colorless transparent materials may be carried out so as to lighten the front of the vehicle. Right and left lights must not be illuminated by turns. Headlights installed on GT500 cars must have white and GT300 cars must have yellow or amber colored covers.

Tail lamps, brake lamps and direction indicators etc.,:

Tail lamps and brake lamps 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. The diameter of the indicators' lens surface is required to be at least 3cm. Ducts can be connected to openings which are created by the removal of other original light assembly.


Prohibited systems etc
- Anti-lock braking systems (ABS)
- Traction control systems
- Semi-automatic or automatic gearboxes
- Power actuated clutches
- Electronically or automatically-adjusted final drive differential systems (ex.:differentials with air pressurizing or hydraulic slip controls, or with electronic controls and/or outer pumps)
- Electronically or automatically adjusted shock absorbers, suspension or ride height adjustment
- 4-wheel steering
- Moveable ballast
- Electronic control systems with closed-loop circuits other than engine
- Gear change assist systems (the systems which make gear changes easier through the use of a temporal control of propulsion systems when a driver changes gear); Devices that allow a driver to adjust shock absorbers and suspension springs from the driver's seat when the car is in motion
- Telemetry
- Throttle control systems of which the control method is not a direct mechanical linkage between the throttle pedal and engine are all prohibited.

*Usage of speed controller, in order to observe the speed limit in the pit-lane, is permitted.


Specific regulations for 4-door vehicles

Cars having 2 doors on each side for getting in and out of, where a 2-door model does not exist in the family (applied to Group A cars of Article 255 of Appendix J) of the model concerned and approved by the ASN (national body, recognized by the FIA. ie: JAF).

Rear doors:

Rear doors may be extended in their width. They may be identical to the extended outer surface of the rear fender. However, the configuration of the car when viewed from the side must be maintained, other than the part cut for the forming of wheel arches. The opening/closing function for rear doors is unrestricted.

Bodywork structure around rear doors:

It is permissible to process or modify the main bodywork (monocoque construction) such as an outer sill in order to accommodate rear complete wheels within the limitations and conditions in the regulations.

Rear window glass:

It is not permitted that the shape of the rear window glass be modified, but its operating function does not need to be maintained.
240sx, soon to be S13.5, future mods are wheels and hopefully paint and the rest of my conversion.

(96 eclipse RS 5-speed, magnaflow exhaust,chrome headers,cold air intake,denso iridium sparkplugs,new kumho tires )******EDIT totalled car now*******
EVOclipse is offline   Reply With Quote
Old 12-31-2007, 11:33 AM   #6
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Re: JGTC rules ??

check this site out, its their official site, the rules are some where there. Or they will post it later in the "news" section.
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