Corvette C3 Headlight Facts

Driving a fast car at night can be exhilarating, but also risky. It is so easy to “out drive” your old sealed beam OEM headlights. Even newer halogen replacement headlights limit the distance that you can illuminate the road ahead. In this article we are going to examine the different options and discuss what alternatives make sense and why they are better.

The C3 Corvette came with four sealed beam, tungsten filament incandescent headlamps in what is known as a “quad” arrangement. This concept was introduced in 1958. Two lamps dedicated to the low beam setting, with two for high beam where all four are illuminated on high beam setting only. At the time they were introduced this was a marked improvement over the older 1940’s vintage two head light arrangement with each lamp containing two filaments, one for low beam one for high beam. They are called “sealed beam” because the lamp and lens are all one piece. From a spectral viewpoint the light they cast is yellowish because of the temperature of the filament when energized.

The next brake through was the introduction of tungsten halogen lamps in 1983. The light they cast is yellow-white. The use of inert gas like iodine or bromine inside the lamp instead of just a vacuum helped in three important ways:

* Eliminates darkening due to the tungsten in the filament plating the inside of the bulb.
* Increases light output because the filament operates at a higher temperature but the same current as a non-halogen bulb.
* The filament is regenerated during the halogen cycle which allows the tungsten to plate back on to the filament.

Another version of halogen lamps is Xenon halogen headlights. These are filled with Xenon gas and produce a distinctive blue hue when illuminated. They typically last longer, and have higher light output at a given current. These should not be confused with Xenon HID lamps which run on AC current and require special electronics including a ballast to function.
An important factor in making any lamp brighter is current. Because of the limitation of the standard wiring on the C3, just changing bulbs will not affect brightness – and your ability to see at night – as much as you would hope. That is because the wire gauge used in the stock harness is sized for the old standard tungsten filaments and therefore limits the current because of the voltage drop which can be sourced to the headlamps. A drop of as little as1.3 volts can reduce headlight output by 30%! In addition all of this current is routed through the headlight switch on the dash instead of a heavy duty relay which most modern lighting systems employ.

Putting it All Together

So if you are like a lot of performance drivers you really want to see a long distance on those dark roadways while moving along at a good pace.  Something needs to be done to improve the view beyond just switching to halogen bulbs. Fortunately SpeedDirect has developed NeverNight TM lighting system for C3 Corvettes. This system provides a heavy 12 gauge harness and relay system with a huge 8 gauge wire from the alternator. This accomplishes several things:

Much more current to the headlamps than is possible with a stock harness. (You can actually melt the wires and harness connectors if you just stick really bright bulbs in a stock harness.)
Drastically reduces the current through the dash mounted headlight switch. (The gets pretty toasty with brighter bulbs.)
If this weren’t enough we speced super bright Xenon lamps to give the most light available in a C3 and still fit in the pop up covers! You wont believe what these blue white search lights will do on a dark road. For safety and high performance, switching to the NeverNight harness and Xenon lamps will greatly enhance your ability to see where you are driving especially on a dark, moonless night. Installation is simple and can be accomplished in an hour or so with ordinary hand tools, and no hacking or splicing your stock wiring. It can all be returned to stock if you choose to do so – but why? Once you have driven a NeverNight TM system you will never go back to the yellow “candles in the wind” of the original headlights.