Rear Fog Lamp: Red 921 LED replacement?

[NYtoVT]

^ The recent research articles brought forward by lighting-minded brothers such as outahere really lit a fire under my ass with respect to the rear fog.

 

Since I knew the task should've been easy on the wifey's peanut-eye WRX sedan, I pretty much went out and did it on that car nearly right-away, and I truly felt better about her ( the wifey, not the car ) safety during this past winter's rather awful storms and the single episode of near white-out fog that we saw here in NE-Ohio.

 

exactly!

[TSiWRX]

Oh, and speaking of.....

 

I did an informal comparo with the wifey's WRX's setup ( http://forums.nasioc.com/forums/showthread.php?p=20546526#post20546526 - my contribution to that Nabisco thread ), which utilizes the high-burn filament for that particular dual-element marker bulb ( I forget the bulb number ).

 

The LGT's setup is definitely brighter and more attention-getting, head-on/end-on, but from off-axis, the wifey's setup definitely gets the edge.

 

I definitely will have to seek some way of increasing "fill" of that area, taking advantage of the many-faceted reflectors in the back-up light's unique housing area.

 

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On a side note - one disadvantage of this particularLED setup is that it does NOT generate appreciable heat. As such, this element will not be self-cleaning/clearing, which is a significant disadvantage in foul-weather situations.....

[Aczwild]

I think I'm gonna try to mount the LED's in the lower part of the housing to keep the reverse light free of clutter and my goal will to be to make the lower area the fog, so the brightness is boosted when the fog is switched on (yeah I'm anal like that too, I have to have the switch)

[TSiWRX]

^ The lower area would definitely be better than my current setup, which is on the "high" area.

 

In retrospect, I can see how a higher-sightline vehicle, such as an SUV or a tractor-trailer, would lose-sight of my current rear-fog setup, up-close.

 

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Crappy cameraphone pix - sorry!

 

To help everyone "orient," that's my left tail-light housing. I've got the Jinsu/Rockblocker "cleared stacked ovals," which has a clear cut-out section for the back-up/reverse light. I've used a yellow bracket box to highlight the LEDs I've added back there.

 

Sorry for the bad editing - the lettering off to the left reads "Rear Fog," and there's one denoting the "Top" row, and one for the "Bottom." If you'll reference the LEDs that I've cited before, they're configured as:

 

X X X-- --X X X

X X X-- --X X X

 

Where each "X" denotes an LED element, and the "--" are the circuit and wire leads (which feed into the center of the "plate" I made).

 

I hope to have some night-time pictures (as well as better pictures overall, with my actual digicam) tonight, but as Anna's sick ( and just today, so is Sara ), I'm honestly not sure this will be done until the weekend. If at all possible, I'll give it a try.

 

Regardless, I did get to "preview" the setup this AM.

 

Although the weather was clear and my timing (I was running late, due to the wifey now also being sick) was later than I'd have liked (it was starting to really brighten-up outside, I was well-past the dawn horizon), I did get to park the car at the end of my driveway, and step-back from it for a bit.

 

I'm pretty darned satisfied. For the minimal expense (not counting the cost of the "in-progress"/extra tail-lamp assembly) and trouble, I'm *VERY* satisfied at end-on light output. It's pretty much as bright as I could have desired for, akin to burning either the high element of the 7443 brake-lamp below or the output of the single high-burn element of the 7440 signal/hazard lamp above it.

 

Now to work on "fill" and off-angle visibility.....

 

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PS: If I had it to do over, I'd definitely also put the light even farther out towards the rear lens, and also make it less angled towards the outside flank of the vehicle. This (the more "outward" displacement) would help maximize visibility of the LEDs from higher-riding and closer-following vehicles (still, I think that a "bottom" mount may be best, with this concern), as well as further maximize end-on visibility (my original thought was that I'd follow the contours of the rear lamp housing, thus to also offer some slight off-axis coverage; in-retrospect, I should simply have devoted a "fill"/off-angle consideration to this issue, and made this unit fully devoted to rear-on/end-on performance.

[TSiWRX]

OK, better pictures/update.

 

http://i170.photobucket.com/albums/u259/TSi_WRX/FogOffDetail.jpg

 

This is a much better picture of the same thing as depicted in the attachment above. You can now easily see how I've configured the LED arrays that I bought, as well as the hole drilled through the metal backing strip/bracket, which allows for pass-through of the wiring.

 

Up close like this, no, it's not pretty, but from just standing at the back of the car or from a following vehicle, it looks just fine - and in the latter scenario, if one didn't know that the item existed, you'd likely not know of its presence at all, visually.

 

http://i170.photobucket.com/albums/u259/TSi_WRX/FogOn1.jpg

 

Here, I've engaged the rear parking/side marker, as well as the rear fog.

 

It's a trick of the camera that the rear fog appears only as bright as the rear marker (low-burn) element. The rear fog is noticeably brighter, and not just by a little bit, either.

 

My lack of photography skill contributed to this illusion, and I sincerely apologize.

 

You'll see what I mean when you examine this picture below, for-comparison --->

 

http://i170.photobucket.com/albums/u259/TSi_WRX/FogOn2.jpg

 

Note that in this picture, the highlighted door puddle/courtesy light as well as the interior dome both seem to be nearly as bright as the rear fog and side marker element. This is, I assure you, not the case in real-life. Again, my lack of camera skills are to-blame.

 

My original intent with this picture, versus the one before, was to get a better illustration for y'all of the "end-on" visibility of the rear fog setup, as I have it now. However, when I looked at the pictures a bit more this morning, while editing them, I noticed this rather strange phenomenon - that somehow, all of the lights in my picture seem to be of the same intensity.

 

My apologies!

 

In any case, I hope y'all enjoy!

 

 

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BTW, again, these pictures were taken in "twilight" situations. Dawn was well over the horizon by the time I got to take these pix.

 

For the first picture above, to examine the details of the LED setup, that was taken with photoflash assistance.

[TSiWRX]

To further discussion, via this past link:

 

http://www.legacygt.com/forums/showpost.php?p=444005&postcount=100

 

I honestly don't know how my current setup would compare to the OEM/JDM fog.

 

Viewing the various pictures in that particular post, I think that the end-results are comparable in terms of overall brightness, but it is very likely that the OEM component would offer more radial illumination due to its physical construct (looking at the detail picture that Rommel put up in post #25 of this thread, on page 2).

 

We'll have to see how long my setup lasts, though. Undoubtedly, Subaru's OEM component is well-armored for automotive use and has been rigorously tested, whereas this aftermarket component may see early demise.

 

For those of you with the budget, Rommel's offer would be pretty enticing.

[holter95]

I have the rear fogs but not the resistor to power it. So if anybody wants to experiment, I'm selling it for $280 shipped. This is the EDM so it will be on the driver's side.

 

 

 

Oh, snap! I've been looking for this! Sadly, $280's too steep at this moment in time.

[Guest *Jedimaster*]

Awesomeness.

 

Wow, I'm really impressed- that looks really nice! Very professional looking- looks like it came from the factory

[TSiWRX]

^ Nah, my work is far from factory.

 

Unlike Jack Bauer and his 24, mine takes place between spurts of Anna's naps.

[TSiWRX]

Update:

 

Took delivery of JDM tails, yesterday, from HKC-Speed.

 

The top is for marker and brake (with the high-burn, 21W element used for the latter).

 

The bottom is actually "blank" over on the left side (USDM driver's side), and the bottom right (JDM driver's side) carries a high-burn single-element bulb (21W, 7440), for rear fog.

 

So, first, I did what was easy - I Dremel'ed out a "socket" for the 7440 on the left-side housing, and simply switched the right-and-left wiring harnesses. Easy. Of-course, if you're able to source a EDM (or other LHD country that uses a rear-fog setup) housing, you're off-the-hook for this.

 

I then replicated, sorta, what I did above with the LEDs.

 

The JDM housing is a bit different from the USDM in that due to the yellow/amber turn/hazard signal use, the central section is shared between this light and the reverse light. Due to this sharing, the central compartment is actually divided into two separate ones, and each compartment offers an access hole (as seen with the USDM housing's reverse-lamp section), covered by a similar, common, block-off plate.

 

So now, I have two separate 6-LED elements in-place - one in the signal/hazard compartment, one in the reverse-light compartment. The former (outboard) faces straight-back to offer best rearward visibility. The latter (inboard) faces slightly out, to help off-angle and also to compensate somewhat for its more inboard location.

 

Both the incandescent fog as well as each of these LED elements are wired to fire off of the lines I trailed into the trunk from my rear-fog setup above.

 

I will be transferring the ERD reverse-light bulbs from my USDM housing into the JDM, too.

[underpowerd]

nice project, and great work as usual, TSi+WRX; keep the pics coming.

I'd really love to have an 08 bumper around to effect something like this into.

[TSiWRX]

^ Ooooooh....an '08 would be super cool - with both of the lower reflector panels ones lit!

 

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Thanks for the encouragement! And honestly, this is a project that I truly felt good about, after completing it. We recently had one heck of a wild summer storm, and visibility on-road dropped to pretty darned nasty levels. As it was during the daytime, and "rear-fog-glare" shouldn't exist under such conditions, I instantly switched these on, hoping that it would give my vehicle some more rear-on visibility. It definitely made me feel safer, with baby-Anna in the car.

 

[ Aside - my current summer-tire of-choice, the Hankook RS-2 Z212s, also performed wonderfully, shunting deep standing water without any untoward behavior whatsoever! ]

 

Viewed first-hand, the pairing of the incandescent 7440 high-burn lamp, along with these LEDs, really makes for a brilliant and unmistakable rear-fog setup. The effect is very nice.

 

I'll get some pix, hopefully, some time soon. The problem is that after Anna goes to bed, I don't usually venture out...she's started to want her room door open (before this, she wanted it hermetically sealed, believe it or not) while she's sleeping. Go figure! This is in-combination with the fact that she sleeps like a Ninja - she doesn't ever really sleep! I swear!

 

And since it gets dark here, really, only after 10PM.......

 

I'm currently contemplating "reversing" the standard JDM tail-light setup to the Blitzen ( ref: http://www.legacygt.com/forums/showpost.php?p=1824704&postcount=90 ), since I've already "bored out" the necessary hole on the driver's side, this would literally be, like, a 5-minute mod.

 

I think that doing so may give me a bit more safety factor, overall, as the brake-lights would occupy the larger of the two reflector assemblies (the lower ones), and would also displace the rear fog "higher-up," to be more within the line-of-sight of, in-particular, SUV/truck/commercial drivers.....

[TSiWRX]

OK, so I took some pictures in the dark, and they came out horrible, as I was too lazy to bring out the tripod. I promise to do that at a later date.

 

Similarly, after looking at these pictures, I realized that I should've taken at least one close-up of my JDM setup..... Again, I apologize for the oversight, and will do so ASAP.

 

For now --->

 

http://i170.photobucket.com/albums/u259/TSi_WRX/lgtwflash.jpg

 

^ That's with the camera's flash.

 

You can see how strongly the reflectors buried in the tail-lamps "retro-reflect" light. This is despite the fact that I have the Jinsu Power/ClearGuard "Cleared Stacked Ovals" overlays on top of my tails. Look also at the registration stickers for my rear plate, lighting-up from the photoflash!

 

http://i170.photobucket.com/albums/u259/TSi_WRX/lgtwoflash.jpg

 

^ That's without the flash, and it gives a good idea how bright the rear fog truly is.

 

 

For those who are wondering:

 

http://i170.photobucket.com/albums/u259/TSi_WRX/wrxwflash.jpg

 

^ Wifey's WRX ('05), with flash. Check out how strongly "retro-reflective" her license plate is....huh, I wonder why my plate, above, doesn't do that?

 

http://i170.photobucket.com/albums/u259/TSi_WRX/wrxwoflash.jpg

 

^ Wifey's WRX, without flash.

 

For my wife's WRX, this is the same mod as-detailed on the NASIOC "rear fog" thread, albeit without any secondary switchgear (as-is my wife's preference). Simply switching on the front fogs switches on her rear fog.

[outahere]

Installing a rear fog in the tail lamp assembly certainly leads to a clean installation, and it is how some OEMs do it, but from a performance perspective, it may not be optimal.

 

"Mortimer (1969) studied the distance at which a separation between two red lights could be detected. ..............The results show that the larger the separation, the better the performance..................Helliar-Symons and Irving (1981) investigated how rear fog lamps influenced the visibility of brake lamps in fog. They found that even a fairly small separation distance of 50 mm between the fog and brake lamps improved the visibility of the brake lamps considerably. ....... Akerboom et al. (1993) reported that rear fog lamps introduced an ambiguity that led to false alarms and slow reaction to brake lamps. A CHMSL reduced, but did not eliminate, these disadvantages. ..................."

 

From: HISTORICAL DEVELOPMENT AND CURRENT EFFECTIVENESS

OF REAR LIGHTING SYSTEMS, Report No. UMTRI-99-31

October 1999, The University of Michigan Transportation Research Institute

 

To reduce ambiguity, I would think a color other than red would be beneficial. Maybe amber? Or blue? Or green? But red is currently the only legal color, I believe.

[TSiWRX]

^ Agreed.

 

Separation is far from ideal, and yes, I can definitely see how, particularly if used incorrectly, it can lead to both the "false alarms" as well as the "slow reaction to brake lamps."

 

I find it facinating how, in all these years, no-one has come up with a better strategy....and also how what was then noted *still* holds true. I don't remember who it was that pointed me to the videoclip on YouTube, but it was an early-'90s, IIRC, video, British in origin, about the dangers of using rear fogs improperly, and it precisely showcased these very concerns.

 

Indeed, I believe that the only legal color (worldwide?) for rear fogs is red. Amber would cause, I fear, confusion/ambiguity with turn signals (even moreso in areas of the world where an amber rear turn signal is mandated), and blue may create glare concerns, while both blue and green (the latter also, to many, is instinctively rooted in the "green means go" sense) are, in various areas of the globe, restricted to emergency vehicles only.

 

I really like how the F1 cars use a high-frequency flashing (not strobing, although I must say that the near-strobe frequencies that I see as aftermarket on various bikes, as well as on some of our local buses/transports, really are eye-catching as well) red, but I think that on public roads, that may much more easily be confused with brake-actuation - and I can only imagine such an issue being compounded in concern (i.e. worsening) when there's a line of traffic, all strobing away.

 

I can only hope that the automotive engineers, lighting engineers, and traffic/automotive safety engineers are working on this for us, outahere.

[outahere]

........I can only hope that the automotive engineers, lighting engineers, and traffic/automotive safety engineers are working on this for us...........

 

 

There is research being done on this, especially with regards to rear lighting on snowplows, where about 70% of the collisions are rear enders from other vehicles.

 

The snow plow research that I have seen (and I have only read a little) shows that best results are obtained with a vertical LED array (3-4 feet) at each rear corner of the plow, or a horizontal array across the back (i.e. bigger is better).

 

Steadily burning LED array was superior to a flashing LED array, in terms of visibility and "passing confidence".

 

Red lights are perceived as being of higher brightness than yellow lights having the same luminance.

[outahere]

A dozen of these, mounted on your rear bumper, should do the trick:lol:

 

http://www.delcity.net/delcity/servlet/catalog?parentid=790501&page=1

[TSiWRX]

^ I'm sure that my local truck-stop superstore would gladly take my debit card.

 

There is research being done on this, especially with regards to rear lighting on snowplows, where about 70% of the collisions are rear enders from other vehicles.

 

The snow plow research that I have seen (and I have only read a little) shows that best results are obtained with a vertical LED array (3-4 feet) at each rear corner of the plow, or a horizontal array across the back (i.e. bigger is better).

 

....

 

Red lights are perceived as being of higher brightness than yellow lights having the same luminance.

 

If I only drove a snowplow! :wub:

 

Steadily burning LED array was superior to a flashing LED array, in terms of visibility and "passing confidence".

 

*NOW* I understand, finally, why F1 teams don't complain about that rear foul-weather light......

 

Leads to less passing confidence!!! FTW!!!

[A_Tang]

That's looking very sharp man. I've been plotting to do something similar on my '07 wagon. The reflector area next to the turn signal seems an ideal area for the LED panel.

[Krisso8]

has anybody done a write up on rewiring the back up light with a switch and changing the bulb to a red 621 bulb to be used as a rear fog light during inclement weather?

[A_Tang]

has anybody done a write up on rewiring the back up light with a switch and changing the bulb to a red 621 bulb to be used as a rear fog light during inclement weather?

 

I've searched here and not found one yet.

[Krisso8]

I figured. it seems simple enough, but I don't want to start splicing until I get some kind of confirmation, thanks.

[nstg8r]

It's been done on 5th Gens...

 

http://legacygt.com/forums/showpost.php?p=4881461&postcount=40

[Krisso8]

Was able to convert my driver side back-up light to a fog light. I did this by wiring the power wire from the back-up lamp to the aux power and installing it with a relay for a switch to turn it off and on when needed. I bought a red 921 bulb online, but the bulbs red coating would melt off with extended use and makes the light pinkish (which I hate). I'm not a fan of using L.E.D. (no reasonable explanation) but I ordered one online to fix the "pink light" issue. When there was no other way to fix the "pink light" issues, I opted to buy LED bulb. I got the bulb and the "pink light" disappeared and the color was amazingly red. The issue now, the bulb was only as bright as the rear park lamp...just ordered a new LED bulb that should be brighter.

 

I would update when I get the new bulb