Anyone who’s driven a C4 on a back road at night knows its headlights are substandard for a high-performance sports car. Shortly after I bought my ’95, I learned that one moonless night in Colorado. On a trip from Michigan to California, I exited I-76 in Sterling and was rolling west on two-lane State Route 14 headed for Ft. Collins, about 110 miles away. As the the street lights of Sterling receded behind me, I accelerated through 60-mph and then 80-mph, and ﬂicked on high beams. “Wow.” I thought as I slowed to about 70, “I’ve got to do something about this lousy lighting.”
My solution? I swapped the stock sealed-beams for aftermarket headlight assemblies, first, a set of German Hellas. Then, a couple of years later, a pair of French, Cibies fitted with 130/100-watt “H4 Rallye”, quartz-halogen bulbs. Back in those days, Cibies with high-power bulbs, while quite illegal, was the best lighting you could get for a C4, short of adding auxiliary driving lights.
Maybe ten years ago, high-intensity discharge (HID) headlight conversions became available for C4s. I considered going that route in search of even better lighting for high-speed driving at night–but only until I learned more. What I found either: 1) were HID bulbs in reflectors originally intended for incandescent bulbs–a product which was low cost, didn’t improve lighting much and existed mainly to give the appearance of bluish HIDs to other drivers, 2) required modifications and/or fabrication work to install or 3) was an improvement in lighting, but was, also, quite expensive. One conversion I found like that cost over $1000.00 just for the parts. I decided to stick with my aftermarket quartz lights but keep searching for something better and, also, more affordable.
In the last few years, with the increasing use of light-emitting diode (LED) lighting products by original equipment manufacturers, HIDs may become obsolete because of their cost, complexity and weight. “GE Lighting,” General Electric’s consumer “light bulb” division, brought LED headlights to the aftermarket when, in late-2012, it introduced the “Nighthawk LED” brand. At this writing, in late Fall 2014, there are two Nighthawk LED products which fit vehicles with either 7-inch round headlights (12-volt ’55 Corvettes and all ’56es and ’57s) or 5x7-inch rectangular headlights (all ’84-’96 Corvettes).
Initially, GE’s target market for Nighthawk LED headlights was the heavy-duty, long-haul trucking industry. Soon, GE Lighting noted a fair amount of the sales were not going to truckers. The product was also being purchased by automotive enthusiasts interested in personalizing their vehicles and/or improving headlight performance.
This review of GE Nighthawk LED headlights covers the 5x7-in size used on a C4. We tested the “Second Generation Nighthawk LED” released in the Fall of 2014, just before we began our test. The installation was straight forward requiring no modifications or fabrication work to headlight mountings or underhood wiring.The Nighthawk LEDs go right into the stock C4 headlight “buckets” using the stock hardware. Each has a pigtail wiring harness which connects to the stock headlight plugs, however, we had some difficulty when attaching the C4 headlight connectors to the Nighthawks. General Electric opted to use male spade connectors about .015-in. wider than original equipment. They go into the stock female connectors with only .004-in clearance–a very tight ﬁt. More strength may be required to push the connectors together than most people will anticipate. We suggest letting the headlight hang free while you use ﬁngers from both hands to squeeze the two connectors together. Once we got past that part, all we had to do was reinstall the headlight retaining rings and the headlight bezels.
The second part of the Nighthawk LED installation on a C4 is a modification to the fog light wiring behind the right-hand side of the dashboard. C4 fog lights are grounded through the high-beam headlamp filaments. When the fog light switch is on and the low-beams are selected, current flows through the fog lamp relay coil then, through the high-beam circuit to ground. That energizes the relay and the fog lights come on. When the high-beams are selected, voltage on both sides of the relay control circuit is equal, and current won’t flow. The relay is de-energized so, no current flows to the fog lamps, even if their switch is on. This system will not work when Nighthawk LEDs replace stock headlamps because the LED’s have no filaments.
The modification to the fog lamp wiring requires the light green wire coming out of the fog lamp relay be grounded directly to the chassis rather than through the high-beam headlamps. The relay is located behind the trim at the bottom right side of the dashboard in the relay retainer. You will need to remove the lower right-hand trim panel and the knee bolster which is behind it to gain access to the relay wiring. There are four, or, if it’s a ZR-1, five relays there and the fog lamp relay is front row, far right. Four wires will connect to it: yellow, light green, purple and brown. Find the light green wire and cut it and splice in a new section which grounds to the chassis. This will restore fog lamp function when the headlight are on low-beam and allow the fog lamps to be on when the high-beams are on as well as when the low-beams are on.
Because light-emitting diodes require so little current to provide lots of lighting, a pair of Nighthawk LEDs in a C4 draw a little over 2-amps on low beam and about 6-amps on high beam. For comparison, factory sealed-beam lights or standard aftermarket H4, quartz-halogen bulbs pull about 10-amps and 130/100-watt H4 bulbs draw about 16-amps on low beam and 20 on high-beam. Nighthawk LED color temperature is 5600K whereas most quartz-halogens are down, around 3200. As a result, objects lit with Nighthawks will appear more like they look under daylight. LEDs are solid-state devices so they don’t have filaments which break and they don’t give off heat. Because the Nighthawk LED headlight was originally designed for long-haul trucking, it has a large margin of durability in passenger car use due to a diecast aluminum housing, metallic reflectors and encapsulated electronics which are resistant to moisture intrusion and corrosion. The lens is a polycarbonate material which is hard-coated to meet the abrasion requirement of Federal Motor Vehicle Safety Standard (FVMSS) 108. If polycarbonate headlights lenses are not made from proper materials, over a period of time, they turn a sort of frosted yellow. The polycarbonate lens of a Nighthawk LED headlight resists that frosty yellowing problem two ways. First, the formulation of polycarbonate used by GE resists “ultra-violate damage”–what causes the frosty yellow look and, secondly, the abrasion-resistant, hard coating further increases UV protection.
Our initial experience with Nighthawk LEDs installed in my ’95 was a short drive around the neighborhood on which we quickly determined we needed to re-aim the lights to get best results. A short session with the new lights shining on my garage door did the trick. Then, one moonless night, we headed to our “headlight testing area” a long stretch of four-lane highway in some nearby foothills and with no street lighting. We were amazed at the improvement from the Nighthawk LEDs and–that’s comparing them to aftermarket lights with 130/100-watt bulbs, a set-up which, in itself, was an improvement over the stock sealed-beams the car once had.
The GE folks has sent us some illumination pattern information (reproduced elsewhere in this review) and darn if the way the road was lit with the Nighthawk LEDs compared to how it was with the quartz-halogen lighting was very much like what the two light pattern charts predicted the difference would be.
We tested NightHawk LEDs at 80-100-mph and our subjective evaluation is that the lighting on high-beam is much better. The range was a little greater than the quartz-halogens we removed, but where there was significant improvement was between 300 and 650-feet ahead of the car. Illumination from Nighthawk LEDs was about twice as wide at those distances. The increase in the margin of safety you get from that is huge. At 80-mph, you’re covering about 120-ft a second. Having that extra lighting off to the sides that far out in front could mean the difference between seeing a critter getting ready to dart across the road far enough ahead for you to either evade the hazard or stop before it and not seeing it until just before you hit it.
We also tested low-beam operation along a stretch of freeway where there were no street lights. This can be a difficult challenge for night drivers. Since there are no street lights, you need good headlights to travel safely at 65-70-mph, but you have to keep them on low-beam so as not to “blind” oncoming traffic on the other side of the freeway. Typically, low-beam lights have an asymmetrical illumination pattern which is short-ranged on the left side to limit glare to oncoming drivers but longer-ranged on the right side to provide you with good lighting on your side of the road along with illuminating the right shoulder where it’s suggested drivers look when oncoming headlights “blinds” them. Under these conditions, we found the Nighthawk LED headlights to be exceptionally good performers because their low-beam reflectors are shaped to provide a hot spot of light ahead of the car and at right.
Once reason Nighthawk LEDs perform well is because, unlike stock sealed beams or even aftermarket “E-Code” quartz-halogen headlights, they don’t use the same reflector for both high- and low-beam lighting and, thus, don’t have any of the performance compromises that come with high- and low-beams sharing a reflector. A Nighthawk LED headlight has separate light sources and reflectors for high- and low-beam so they can be designed for better performance of each.
If there is a downside to the Nighthawk LEDs for C4s, some may think it’s their price. We’ve seen them for about about $290.00-each on Amazon. Considering, right now, you can buy Hella E-Code 5x7s for 50 bucks apiece, Nighthawk LEDs might seem too costly, but consider this: 1) life expectancy of a standard quartz-halogen H4 bulb is about 320 hours. Life-expectancy of high-wattage versions is even less. Service life for a Nighthawk LED headlight is 15,000 hours, 2) While European E-Code lights with H4 bulbs are better than stock for night driving, none are street legal in the U.S. and, if fitted with 130/100-watt bulbs, they are highly illegal. Conversely, when installed in the stock headlight mounts, Nighthawk LEDs meet U.S. Federal Motor Vehicle Safety Standard 108 and are USDOT approved for on-highway use. They, also, meet Canadian Motor Vehicle Safety Standard 108, 3) HID conversions for C4s which actually work cost over $1000.00 so 4) 600 bucks for set is reasonable considering the safety margin and performance increase Nighthawk LEDs offer when driving a C4 at night.
Bottom line: two thumbs up for Nighthawk LED 5x7 headlights. They’re easy to install and the lighting improvement is substantial. We recommend them for any C4 owner who drives the car in a sporting manner at night or just wants an increased lighting safety margin.
Want more info? Visit the Nighthawk LED web site