Cams Group 2a Regs

[260DET]

Rather than start a new CAMS 2A Sports Car thread................ Trying to work out what electrical devices are required for 2A, it's all very vague. From what I understand after reading all the stuff dipping headlights are required, tail and brake lights, wiper, that seems to about it but 'warning devices' are mentioned. A horn? 

[Duncan]

Well, I've never really run 2a much, and I don't know if you're looking at racing or only speed events....but from the regs....

Schedule A/B – no electrical requirements

Schedule C (racing only)

(h) On each automobile, other than those of the 5th Category, fitted with an electric fuel pump, the pump power supply must cut off in a maximum of six seconds after the engine stops;

Can be a bit tricky depending on what else is in the car. Either the ECU must control the pump based on RPM or similar, or you can use something like an oil pressure switch to earth the fuel pump relay (with an momentary override switch to start the car)

 

(i) Each automobile of the 2nd and 3rd Category shall be equipped with a battery isolation (master) switch which isolates the battery and stops the engine, and:

(i) it shall be capable of being operated by the driver in his normal seated position;

(ii) there shall be a second switch, or a remote means of operating the main switch, from the vicinity of the base of the A pillar on the driver’s side or, for an automobile with no A pillar, in a comparable position; and

(iii) each external device shall be clearly marked by a symbol showing a red spark in a white-edged blue triangle of minimum edge length 150mm;

 

This seems straightforward but I see heaps of cars that do not comply with “stops the engine”. Basic switches just isolate the battery but if you have an alternator the car will keep running. The switch needs some sort of additional circuit that stops the engine eg disconnect the ECU relay, fuel pump relay etc

2A open and closed sports car regs:

2. ELECTRICAL EQUIPMENT

2.1 The component parts of a complete electric system, including generator, accumulator, warning apparatus and lamps, are compulsory. None may be of a temporary kind or addition. The entire electrical system, including lighting and warning apparatus, must be in working order at the start of the competition. The Supplementary Regulations may specify that these devices shall be in order during the whole of the event or allow for penalties in cases where the systems are not working at any time during the event.

 Nothing to worry about here. You just can't have things like external starters that some formula libre cars use in hillclimbs.

 

2.2 A self-starter in proper working order fitted to the vehicle is obligatory, and none of its parts may be removed during the event. Upon failure of the engine to start on the starting motor at the start of a competition, such car may, after the departure of other vehicles from the grid, be push started and in such cases a time penalty of one minute shall be applied to the car concerned, such penalty to be promptly advised to the car’s pit crew; but failure so to notify the pit crew shall nevertheless not expunge the penalty. Supplementary Regulations may require that other means of starting during the event be forbidden and provide for a penalty in case of the non-functioning of the self-starter during the event. Any check of the function of the starter motor will be made at scrutiny and/or in the pre-event marshalling area.

 So this means you need a s

tarter motor

 and a battery at a minimum. Alternator is optional if you don't need to run longer than a battery charge and you are OK to recharge between runs if necessary. Otherwise you need the alternator and associated wiring like battery pos link, battery voltage cable, exciter/charging light in the dash, regulator (normally in the alternator)

2.3 The complete lighting system must consist of at least two dipping headlamps each of at least 125mm diameter or 160cm2 area, each of 35 Watts minimum power; and two tail lamps each of three Watts minimum power (both the above sets of lamps must be not less than 600mm apart) and at least one stop lamp of 20 Watts minimum power. If only one such stop lamp is fitted, it shall be in the central vertical plane of the vehicle. At the start of the competition, headlamps must be in effective working order and correctly aligned; the lens must be protected by a translucent shield.

 Pretty minor really, just need h

eadlights with Hi and Lo beam, tail lights, 1 brake light.

So the minimum setup is pretty simple really.

[Duncan]

I did a bit of work on the wiring in Neil's radical as an example, the only circuits are:

ECU and loom requirements including an ignition and start switch, fuel pump relay and wiring, ECU relay.

Kill switch between alternator/battery and ECU loom (alternator connects to battery side of the switch so single switch kills all power to the ECU)

Radiator thermo fan switch (water temp) and wiring

Oil pressure, oil temp and water temp senders and wiring to the dash

RPM, speed, power to the dash

Brake light switch on the pedal and headlight/taillight switch

There may be a couple of other things but that's about all, it doesn't have to be complex.

[260DET]

Thanks for the assistance Duncan, I thought that there was some reference somewhere to 'warning devices' but could not find it. Have ordered a 8 circuit DIY loom which should get things started, intend to have a aftermarket dash like the MicroTech one http://microtechefi.com/product/ltc-display-dash/ but am not sure if it is plug 'n play with the Haltech Elite.