Sierra only, why swap out the projector?

[mdrew]

The massive thread posted above probably has the answers I'm looking for. I just ran out of energy and patience to wade through 150 pages of back and forth relevant information.

 

I've been trying to ascertain what the real issue is with using the OEM projector when converting the headlights from halogen to HID. I've done this to my last two Sierra Denalis without any negative side effects that I can recall.

 

I am however finding some conflicting points of view with the retrofit to one of the Lexus projectors. I'm not trying to nickel and dime this head light conversion, and if the right thing to do, is to cut open the housings and retrofit the projectors, I'll give that a try. But if there is little to no gain or improvement with the light, then I'd rather spend my time doing something else.

 

So what is the real reason for this swap/retrofit, and is it worth the time and expense, plus the risk of screwing up a perfectly good housing?

[fondupot]

The massive thread posted above probably has the answers I'm looking for. I just ran out of energy and patience to wade through 150 pages of back and forth relevant information.

 

I've been trying to ascertain what the real issue is with using the OEM projector when converting the headlights from halogen to HID. I've done this to my last two Sierra Denalis without any negative side effects that I can recall.

 

I am however finding some conflicting points of view with the retrofit to one of the Lexus projectors. I'm not trying to nickel and dime this head light conversion, and if the right thing to do, is to cut open the housings and retrofit the projectors, I'll give that a try. But if there is little to no gain or improvement with the light, then I'd rather spend my time doing something else.

 

So what is the real reason for this swap/retrofit, and is it worth the time and expense, plus the risk of screwing up a perfectly good housing?

 

The OEM projectors are designed to use halogen light bulbs, and have a certain focal point. Plug N Play HID's might have more light output, but the focal point is now different because of the different size bulb being used.

 

When retrofitting, you are using a real D2S bulb, in a projector designed for a D2S bulb focal point. So the light output will be greater.

 

Does that make sense?

[mdrew]

I get the drift, sorta.... Thanks.

 

So is it the physical size of the projector, the lens design, or combination of both? And what's the difference between the HID and halogen bulb light output that would require a different type of projector housing/lens?

 

I'm a tech guy. I need to understand the "why" from a theoretical perspective.

[fondupot]

I get the drift, sorta.... Thanks.

 

So is it the physical size of the projector, the lens design, or combination of both? And what's the difference between the HID and halogen bulb light output that would require a different type of projector housing/lens?

 

I'm a tech guy. I need to understand the "why" from a theoretical perspective.

 

I don't know how to explain it any differently.

 

A halogen projector is designed for a specific halogen bulb.

 

An HID projector is designed for a specific HID bulb.

 

The halogen reflector is not designed for the light output an HID bulb puts out. So while you might have a lot more light on the road, it will not be as focused. You could have hot spots int he beam pattern, a distorted cutoff, and blinding other drivers. Some Halogen reflectors handle a PNP HID setup well, while others do not. The folks in the HID thread can weigh on that better. Since I am still running the oem halogen setup.

 

When you use a HID projector that is designed for HID bulbs, it will be able to harness the light a lot better. And depending on the projector used, you will have a wider beam, more even coverage, a sharp crisp cutoff. And better ability to aim so you aren't completely blinding other drivers.

 

Bottom line is a retrofitted HID setup will be vastly superior to a PNP setup.

 

I have had retrofitted setups in the past, and I have done pnp setups in the past, I even dumbly put hids in a reflector housing (sorry I was young and dumb). The HID projector retrofit wins the contest hands down every time.

[mdrew]

Thanks again. I'll have to give this more thought before proceeding with my decision. For me, it really just comes down to whether or not I want to try and separate the housings to install the HID projector. Not to keen on cutting the back cover off, but not all that excited about melting my housings (accidently), and not getting them to seal correctly.

[SierraAT]

I'd just put HIDs into the factory projector and call it a day. That combined with quality LED fogs like the Rigids gives great light output; IMO it's not worth the hassle at all to retrofit other projectors into the housing, but that's just me. I've messed with prying apart housings in the past and it's a pain in the ass, and I hear the lamps in the Sierras and Silverados are especially cumbersome in this regard.

Edited December 5, 2015 by SierraAT

[kristop9]

Going through this now. I'm doing RX350s from Fastheadlights and opened it from the back side. Just cut the square part off and you have good access. I sealed it back with JB Weld and it's rock solid. Could sand it and paint for a cleaner look but no one sees it.

 

HID projectors have a great beam pattern compared to stock w/HID. More light on the road less blinding. It is a job to do this but I enjoy tinkering and learning. The final product is nice too. I could not stand the uneven pattern of the oem projectors w/ HID. I wanted uniform proper lighting.

[mdrew]

Were you aiming the lights in the pic above kristop? The 'kit' from Fastheadlights is what I have been looking at. Are there any videos or instructions with pics that describe the process for this modification? Are there any other methods for welding the housing, other than JB Weld? Epoxy, possibly?

[kristop9]

Just aligning them on the wall. Install complete now. There is a manual in the silverado section on Fasheadlight.con. You can just use tape to reattached the housing or an Epoxy, whatever you feel. JB Weld is easy to work with and is rock solid. Great light output but you need some time and basic mechanical/electrical knowledge to get them in correctly and to hook up the high beams. Fun project.

[SierraAT]

That looks great. If I had the patience to do it these days I would.

[Kerrslight]

Phil, the guy that owns and operates fast headlights and all these retrofits posted these pictures. I think this is what your looking for. Great picture comparison of Stock bulb/projector, HID/stock projector, and HID/HID projector. Very drastic improvement.

Took some pics tonight showing the difference amongst setups. I used just one projector in the comparisons.

Factory 2015 GMC Sierra projector and bulb


Factory 2015 GMC Sierra projector with 35 watt 5000k Morimoto HID setup



RX350 projector with STi clear lenses/tuned with 35 watt 5000k Morimoto HIDs. *FXR has same/similar performance

[mdrew]

I'll have to call Phil and get some more details. I have my vette torn apart in the garage right now, so I don't have room for the truck. That means I get to lay on the ice and snow in my driveway. ..with numb fingers.

 

This project might have to wait till spring.

[fondupot]

I'll have to call Phil and get some more details. I have my vette torn apart in the garage right now, so I don't have room for the truck. That means I get to lay on the ice and snow in my driveway. ..with numb fingers.

 

This project might have to wait till spring.

Yea I would wait until you have a warm, dry place to work.

[Haus_Z71]

Looking at that 2015 factory lighting is such a joke. I can't believe someone signed that off and said its safe and sufficient.

[Travis Whitmore]

RX350 projectors added to the "to do" list!