¿ªÔÆÌåÓý

ctrl + shift + ? for shortcuts
© 2025 Groups.io
  1. PacNW928
  2. Topics

Any decent LED retrofits for H3 out there?

 

While I realize that the short answer is probably "no," because any attempt to replicate the optics of an incandescent filament with LEDs on a board is inevitably a bit compromised, I know that sometimes one can get lucky and find an LED retrofit that actually works OK in a given lamp if not universally.

And so I've been thinking:
1) The driving lights on the S4 are there primarily to provide the flashing function when the headlights are stowed, so there's not much downside to a somewhat-flawed beam pattern (i.e. I'm not convinced they contribute noticeably to the net illumination you get when the high beams are turned on).
2) While looking through the wiring diagrams for something else the other day, I was surprised to discover that the driving lights on the S4 are NOT powered through a relay, but rather all their current goes through the column switch (not just for flashing, which is typical, but also when the high beams are on, despite the current for the high beam filaments within the headlights going through a relay).

My first instinct in response to #2 was that I should add a relay, just like I would for an older car that didn't have any headlight relays to begin with.? But considered in conjunction with #1, maybe the more elegant means of prolonging the life of the column switch would be to simply replace the driving light bulbs with LEDs!? Have any of you tried this, and have you found a solution that doesn't suck?

Thanks,
Joe
 

Not really, no.? There are H3 LEDs out there, but they are too big for our very 'not very deep' housings.
The ones that do fit, are NOT as bright as OE wattage either, because they are compromised by heat dissipation.

I tried about 4 different ones, including woodpeck's kit, they all came out in under 10 minutes.


On Sun, Dec 10, 2023 at 5:30?PM Joe Elliott <jelliott4@...> wrote:
While I realize that the short answer is probably "no," because any attempt to replicate the optics of an incandescent filament with LEDs on a board is inevitably a bit compromised, I know that sometimes one can get lucky and find an LED retrofit that actually works OK in a given lamp if not universally.

And so I've been thinking:
1) The driving lights on the S4 are there primarily to provide the flashing function when the headlights are stowed, so there's not much downside to a somewhat-flawed beam pattern (i.e. I'm not convinced they contribute noticeably to the net illumination you get when the high beams are turned on).
2) While looking through the wiring diagrams for something else the other day, I was surprised to discover that the driving lights on the S4 are NOT powered through a relay, but rather all their current goes through the column switch (not just for flashing, which is typical, but also when the high beams are on, despite the current for the high beam filaments within the headlights going through a relay).

My first instinct in response to #2 was that I should add a relay, just like I would for an older car that didn't have any headlight relays to begin with.? But considered in conjunction with #1, maybe the more elegant means of prolonging the life of the column switch would be to simply replace the driving light bulbs with LEDs!? Have any of you tried this, and have you found a solution that doesn't suck?

Thanks,
Joe



--
---
Gustatus Similis Pullus
 

How long ago did you try Woodpeck's kit?? I just looked it up and noticed that they're advertising the current offering as being "new for 2022."? (Of course, they're also making the contradictory claims of only 450 lumens output and "equivalent to 80w Halogen bulb" [which would be >2000 lumens], so I probably shouldn't hold my breath.)

-Joe
 

6mo. ??
I dont expect any H3 ever to work in our shallow housings.? Ever.? And be better.? Ever. ?


---
Gustatus Similis Pullus


On Wed, Dec 13, 2023 at 11:31 Joe Elliott <jelliott4@...> wrote:
How long ago did you try Woodpeck's kit?? I just looked it up and noticed that they're advertising the current offering as being "new for 2022."? (Of course, they're also making the contradictory claims of only 450 lumens output and "equivalent to 80w Halogen bulb" [which would be >2000 lumens], so I probably shouldn't hold my breath.)

-Joe
 


Regarding your question about suitable H3 LED options: Porsche specified 55-watt H3 halogen bulbs for the fog and auxiliary driving light locations. 55-watts (halogen) is the equivalent?of 1240 lumens. So when looking for LED alternatives, you would want similar or more lumens in order for them to be effective. As pointed?out, there are not many H3 LED bulbs that offer comparable lumens and will fit in the factory location. Higher-lumen H3 LEDs often come with large power?supplies and heat syncs that require modification to the light assemblies.

I have experimented with several H3 options, including the Woodypeck variant. They all do not produce enough lumens to be effective to see with. In my latest experiment, I have been using bulbs in both the Fog and Aux locations. They have 1600 lumens per bulb, which is slightly brighter than a 55-watt halogen bulb. I can actually tell when they are on, and the illumination seems comparable to the halogen.?



image.png?
They also come in a , which i am trying for my fog location, which I also really like.
image.png

These bulbs will fit into the fog light assembly. The retaining clips do require some finessing around the base cooling fins. Also, I had to split the casing that houses both leads so I could match them into their respective receptacles. I used a sharp, thin blade (ie, box cutter). It's obvious when you have them in your hands with the fog lights apart.??

Everyone will have their own rationalization to use or not use LED bulbs. For me, I am drawn to the low power utilization if I can match the lumen output and make everything look good. Replacement LED's for the headlights (H4 or 9004) can be found with more than double the lumen output of the standard halogen bulbs with a fraction of the amp draw. So I started there and decided to try and color match 6000k the rest of the front-facing lights.
IMG_9959.jpegIMG_1380.jpeg


On Wed, Dec 13, 2023 at 11:36?AM Jeff Mohler <speedtoys.racing@...> wrote:
6mo. ??
I dont expect any H3 ever to work in our shallow housings.? Ever.? And be better.? Ever. ?


---
Gustatus Similis Pullus


On Wed, Dec 13, 2023 at 11:31 Joe Elliott <jelliott4@...> wrote:
How long ago did you try Woodpeck's kit?? I just looked it up and noticed that they're advertising the current offering as being "new for 2022."? (Of course, they're also making the contradictory claims of only 450 lumens output and "equivalent to 80w Halogen bulb" [which would be >2000 lumens], so I probably shouldn't hold my breath.)

-Joe


--
1992 Porsche?928 GTS Japan market
 

Well if they actually produce 1600 lumens, that's promising, but it still bothers me that no one bothers to orient the LED chips transversely to properly mimic the transverse filament of an H3 bulb; it feels like they design a retrofit for an H1, then cut it down (hopefully getting the center of the LED 18 mm from the flange) and stuck it on an H3 flange.

On Wed, Dec 13, 2023 at 5:53?PM Michael Benno <michael.benno@...> wrote:

Regarding your question about suitable H3 LED options: Porsche specified 55-watt H3 halogen bulbs for the fog and auxiliary driving light locations. 55-watts (halogen) is the equivalent?of 1240 lumens. So when looking for LED alternatives, you would want similar or more lumens in order for them to be effective. As pointed?out, there are not many H3 LED bulbs that offer comparable lumens and will fit in the factory location. Higher-lumen H3 LEDs often come with large power?supplies and heat syncs that require modification to the light assemblies.

I have experimented with several H3 options, including the Woodypeck variant. They all do not produce enough lumens to be effective to see with. In my latest experiment, I have been using bulbs in both the Fog and Aux locations. They have 1600 lumens per bulb, which is slightly brighter than a 55-watt halogen bulb. I can actually tell when they are on, and the illumination seems comparable to the halogen.?



image.png?
They also come in a , which i am trying for my fog location, which I also really like.
image.png

These bulbs will fit into the fog light assembly. The retaining clips do require some finessing around the base cooling fins. Also, I had to split the casing that houses both leads so I could match them into their respective receptacles. I used a sharp, thin blade (ie, box cutter). It's obvious when you have them in your hands with the fog lights apart.??

Everyone will have their own rationalization to use or not use LED bulbs. For me, I am drawn to the low power utilization if I can match the lumen output and make everything look good. Replacement LED's for the headlights (H4 or 9004) can be found with more than double the lumen output of the standard halogen bulbs with a fraction of the amp draw. So I started there and decided to try and color match 6000k the rest of the front-facing lights.
IMG_9959.jpegIMG_1380.jpeg


On Wed, Dec 13, 2023 at 11:36?AM Jeff Mohler <speedtoys.racing@...> wrote:
6mo. ??
I dont expect any H3 ever to work in our shallow housings.? Ever.? And be better.? Ever. ?


---
Gustatus Similis Pullus


On Wed, Dec 13, 2023 at 11:31 Joe Elliott <jelliott4@...> wrote:
How long ago did you try Woodpeck's kit?? I just looked it up and noticed that they're advertising the current offering as being "new for 2022."? (Of course, they're also making the contradictory claims of only 450 lumens output and "equivalent to 80w Halogen bulb" [which would be >2000 lumens], so I probably shouldn't hold my breath.)

-Joe
 

For the other part of your question, it's a well known thing with the 944 to make/buy a separate headlight relay harness. This has a couple of positive things going for it. First, you avoid fires from the current that can go through older, oxidized contacts in the switch. Second, getting power to the lights straight from the battery or alternator results in significantly higher light output. Lumen output is not linear with input voltage, so small decreases due to oxidation/corrosion in the wiring, at the switch, or basically anywhere in the circuit, will make the system terrible, quickly.

I've asked, in the past, why folks don't do it on the 928, but I didn't quite understand the reasoning at the time and dropped the idea. I'm still not totally sure where I'd put the relays in the engine bay, even if it were viable.

Good luck.

1 - 7 of 7