11 replies to this topic

[CorsaGT]

I haven't seen many posts regarding using LED headlights for dipped beams when upgrading (instead of HIDs). I've just fitted a set to my car so I figured I'd share my thoughts. 

 

LED headlights seem to be undergoing a lot of development in the last couple years, so new aftermarket options are still emerging. I ended up buying these:

 

http://www.ebay.co.u...=STRK:MEBIDX:IT

 

After doing a bit of research, it seems that many of these headlight bulbs use Philips Lumileds or Cree LEDs. I haven't looked into the others, and I didn't bother looking at any bulbs which didn't specify which LEDs were used. When buying some of these Chinese bulbs, you're paying for a name-brand LED (hopefully) in their packaging and supplied with their own LED driver box. Compared to the HID kids, this packages much tidier without having the bulky ballast boxes. The bulbs I bought above come with two of these in each bulb, so I feel a bit more confident that they're genuinely putting out 4800 lumens per bulb:

 

http://www.cree.com/...nal/XLamp-XHP50

 

They're also available in two general varieties: those with cooling fans on the back of the bulb and those with passive copper (supposedly) woven cooling. Most of them have fans. I can't imagine how a cheap fan will outlast a quality LED, so I opted for the passive cooling. While the lights were on for about an hour while I was adjusting the angles, the copper mesh started getting warm to the touch but not enough to cause a burn or likely damage the fender liner which it lays against.

 

Here's what these things looked like sticking out of the back of a VX headlight housing:

 

 IMG_20160812_163945.jpg   94.88KB   45 downloads

 

Obviously the mesh gets squished against the fender liner, but the idea is to maximize the surface area.

 

I don't have a camera to take a suitable picture of the effectiveness at night, but it's a major improvement. I've owned my VX for about a week and have driven it twice at night, wondering how anyone can actually drive these things at night with just the dipped beams. Really, really awful. With the new lamps it's absolutely solved that issue and seems comparable to any modern car with good lights I recall having driven.

 

[Mike (Cliffie)]

Nice idea. A pic taken at night with the lights on would help others judge the usefulness however.

 

 

[fezzasus]

No doubting it's an improvement, however the big problem is the dimensions of the dipped beam projector. It just doesn't produce a good distribution of light, it also has cut off designed for halogen which means it will dazzle when fitted with HID or LED bulbs (which require level cut offs).

 

 

[CorsaGT]

No doubting it's an improvement, however the big problem is the dimensions of the dipped beam projector. It just doesn't produce a good distribution of light, it also has cut off designed for halogen which means it will dazzle when fitted with HID or LED bulbs (which require level cut offs).

 

 

 

Absolutely correct. I fully understand I'm using an LED bulb in a halogen lens and that it isn't ideal or designed optically correct. The rest of the internet seems to feel that HIDs/LEDs in halogen projector housings -typically- produce a beam pattern that is acceptable and with minimal glare (this cannot be said for HIDs in halogen reflector). It also seems to widely vary from projector-to-projector, so possibly the VX projects are not well-suited for HID/LED "upgrades". I'd like to park my car next to another VX at night with factory lamps to better evaluate the light pattern.

 

Question about UK driving culture - In America we typically momentarily flash main beams to oncoming traffic on single carriageways who have not turned off their main beams soon enough. Is this practice common in the UK as well? If my lights are aimed too high or produce glare can I expect that I'll get some feedback while driving?

[ayresyy]

 Flashing people who leave there high beams on is fairly normal in the UK. Not really the best way to find out if your own lights are too high/bright though 

[CorsaGT]

 Flashing people who leave there high beams on is fairly normal in the UK. Not really the best way to find out if your own lights are too high/bright though 

Absolutely. I was rather pedantic when aiming them (ECE regs, tape and tape measures were used) but I don't know how perpendicular my ground was to the wall.

[Mr Apex]

That cooling mesh is a complete waste of time. It won't provide any meaningful heat transfer and dissipation. Those LEDs, running at high drive current, need serious heat sinks or they will deteriorate very rapidly.

[CorsaGT]

That cooling mesh is a complete waste of time. It won't provide any meaningful heat transfer and dissipation. Those LEDs, running at high drive current, need serious heat sinks or they will deteriorate very rapidly.

 

 

The cooling mesh design is a fairly common approach in aftermarket LED headlight bulbs; are all of these companies wasting their time? 

 

The L70 times quoted from Cree (30,000+ hours) are at 105C are 12V/1A. You make me want to buy another set and do some bench testing with a few thermoucouples to quantify the effectiveness of the cooling mesh and the impact on the bulb life. 

 

In any case, I'll be sure to post up when they fail in my car! 

[Mr Apex]

Those LEDs are running at max drive current, at which point they are running under their least efficient allowable condition. You are probably looking at around 28watts of thermal energy to dissipate. They are using a heat pipe to move that energy to the mesh, which is sensible. The problem is that the structure of the mesh does not allow heat to move through it in order to use the surface area that it provides. Heat conductivity needs cross sectional surface area. So in this system, you will end up with a heat pipe that is very hot at both ends. Heat pipes need evaporation and condensation cycles in order to work. A heat pipe that is hot at both ends is just a steam chamber and won't cool anything.

[fezzasus]

 

No doubting it's an improvement, however the big problem is the dimensions of the dipped beam projector. It just doesn't produce a good distribution of light, it also has cut off designed for halogen which means it will dazzle when fitted with HID or LED bulbs (which require level cut offs).

 

 

 

Absolutely correct. I fully understand I'm using an LED bulb in a halogen lens and that it isn't ideal or designed optically correct. The rest of the internet seems to feel that HIDs/LEDs in halogen projector housings -typically- produce a beam pattern that is acceptable and with minimal glare (this cannot be said for HIDs in halogen reflector). It also seems to widely vary from projector-to-projector, so possibly the VX projects are not well-suited for HID/LED "upgrades". I'd like to park my car next to another VX at night with factory lamps to better evaluate the light pattern.

 

 

 

You're welcome to compare them to mine, I can provide standard and full xenon replacement comparisons.

[martinroger]

Bumping this topic... any news ?

[C8RKH]

Just as an aside. Had my 2p01 VX for about 2 months. Std headlights. Only ever driven on full beam at night. NEVER been flashed by an oncoming driver for being too bright! Threads like this are great as they help keep our cars drivable, if you know what I mean. 2 bottles of red wine logic there!