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The AC Cobra Replica Site

People that have visited this page from 20-Dec.-03

Revised at 14 - June.-2007



Wiring looms are not in the sight so, some times we don’t put to much effort.

Let me explain a couple of things so that you can make your thoughts.

Some items in the wiring loom needs to have a correct wire size, if not you will get a performance drop in the involve item.


Lighting is one of those items where the wire resistance will reduce the capabilities of the lamps.

What Happens there.

The output is 100% by 13.2v when the voltage drops, due to wire resistance to 95% that is equal to 12.54v the headlamp will produce only 83% of the rated output.


If the voltage drops to 90% equal to 11.88v the headlamp will produce only 67% of the rated output.


This can happens very easy when your components are not sized correctly and some corrosion is at the connectors.

Even factory cars have this problems due to low sizing of wiring and cheap components.


Length of wiring introduce also more resistance.


Connectors. Those tend to accumulate some dirt and get corroded at the contacts.


I have seen burned connectors due to the amount of heat produce by the resistance.

Water entrance will be a disaster.


Relays. I advise to use for every power consuming item a relay.

This will take the power pick at the initial switch and will help us to have smaller wiring.












Never use wires for the headlamps that are smaller than 2.5 mm˛ the best would be 4 mm˛

Use weather sealed connectors, they are expensive but it will do the job correctly and for the amount of money required for a Cobra it will not empty the wallet.


If you can, protect your wiring loom at the weakest areas, with “Self Amalgating Tape” this kind of tape will shrink and seal the area and doesn’t have glue on it, after several minutes will form a sealed rubber shield.

Use good rated Relays (40 Amps) and we prefer to have the sealed ones. Panasonic make a very nice ones. (Some times they use other name)

Make your wiring routing as short as possible for the high consumers.

Switches, if they are exposed to the weather use the sealed type, we don’t want to have water at the contacts.

Modern switch's have the provision to put a rubber cover boot that makes water thigh.

Ground as much as you can, never use lower rated wire than the feed (+) wire.

Make combinations of earth is not appropriate for power users, so use separate earth for those.

The dash board users can have a combined earth.

Crimp and solder every connection and use shrink tube to seal and to provide some mechanical rigidity.


Headlights or Headlamps.

I have spooked with Daniel Stern and got some e-mail from him with some advice.

He is an Authority regarding the headlamps, wiring and electrical systems of the car.


I did ask for the best headlamps and he answer the next:



Here in Europe you can buy the Wipac Quaoptic and Hellas, do you think that the Cibies will be a better choice?




Take a look at


These are isocandela diagrams for four different 7" round H4 headlamp units.

If you're not familiar with isocandela diagrams, these will look like random squiggles and lines. Think of it as a topographic or "contour" map of the correctly-aimed beam pattern. Each differently-colored line represents the threshold of a particular intensity level, with the color legend located to the right of the isocandela diagram. The diagram is plotted on a chart calibrated in degrees. Straight ahead is represented by (0,0), that is, zero degrees up-down and zero degrees left-right.


To get a mental approximation of the units and amounts under discussion here:

Parking lamp: About 60 to 100 candela

Front turn signal: About 500 candela

Glaring high-beam daytime running lamps (e.g. Saturn): 8000 candela


The parameters to pay attention to are the luminous flux (total amount of light within the beam), the maximum intensity and its location within the beam relative to the axial point (H,V) -- the less downward/rightward offset, the longer the seeing distance -- stray light outside the beam pattern and effective beam width (contained within the dark-turquoise 500 candela contour)


The two lamps at the top of the page are no longer produced, which is sad

-- they're number one and number two in performance in this comparison. Focus on the bottom two diagrams, Cibie vs. Hella.


 Things to notice about these two diagrams:

(1) The Cibie produces a much wider beam pattern than the Hella. The 1000 candela line of the Cibie's beam pattern extends from 25 degrees Left to 25 degrees right, while the 1000 candela line of the Hella extends from 18 degrees Left to 20 degrees Right. At a distance of 50 feet from the car, this means the 1000 candela-and-brighter portion of the Hella's beam is 10.5 feet narrower than that of the Cibie. The 300 cd contour of the Cibie's pattern is *far* wider, extending from 43 degrees Left to 50 degrees Right, compared to 26 Left to 25 Right for the Hella. This means the overall useful width of the beam pattern at 25 feet from the car, as perceived by the driver, will be 40.7 feet for the Cibie and 22.3 feet for the Hella.


2) The total luminous flux (overall amount of light) within the beam pattern is 695 lumens for the Cibie, 463 lumens for the Hella - the Cibie is 50.1% more efficient. (the TLF data is listed as "Luminous Flux" in the readings up above the isocandela diagram)


The high beams for these two lamps (isocandela diagrams not yet scanned in) are very similar in overall performance and amount of light -- the critical difference is that the Cibie's high beam hot spot is located closer to (0,0) and closer to its low beam hot spot. The Hella's high beam and low beam hot spots are separated by a fairly large vertical amount, such that setting the lows where they belong results in most of the high beam light going up in the trees, but pulling the high beams down so they send light straight ahead puts the low beams 10 feet in front of the car.


The Quadoptics are worse than the Hellas.

> The cibies are very difficult to find in Europe, I have found only the

> driving and fog lamps.

Best regards,


Anyone who sells Cibie driving and fog lamps should be able to supply the

headlamps -- the ones you need are Valeo part number 082438