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924RACR · Posted: Fri Jul 20, 2007 10:42 pm Post subject: LED interior light upgrade

Yes, believe it or not, I finally spent some time and money on some cosmetic stuff for my '82 931! Of course, knowing me, you know it's cheap and easy! LOL

I've been wanting to try out an LED upgrade for the dash and interior lighting for a while now; finally got around to ordering some from www.superbrightleds.com and they came in yesterday... so of course I put them in immediately!

I got three types; interior dome light replacement, and dash illumination in blue and white (2 each, to do two gauges in different colors and decide which one I liked). I will have to get some good pics; in particular, the way the dash is set up right now is perfect for comparison.

They were stupid cheap; the dash bulbs are type 74, at $1.20 per bulb, except it seems that the combo (fuel/temp etc) gauge uses the type 74 in a twist-lock base, so I'll have to include some of those in my order to finish the dash. They are a drop-in replacement for the stock bulbs, and include the resistor required to make these LEDs work with a 12VDC supply.

The overhead/dome bulb was the "festoon" style, I got the 39x10mm one with 6 LEDs, but it was barely long enough that I was able to make it work; the 42x10mm 6-led one is the correct size (I was guessing). Either way, it was about $3-4 IIRC. Again, same deal, drop-in replacement with resistor setup included.

Results - the dome light was a massive improvement for visibility in the car after dark - you can actually see probably enough to read! That's due as much to color as the intensity.

For the dash, same deal here; with the improved spectrum/color of the white LEDs over the incandescents, the gauges are actually easier IMO to read, and appear brighter. They also I think appear much more modern, ditching the nasty old yellow bulbs. Kinda like switching from an old 6V headlight to a modern HID!

As for the blue - very cool, interesting, but not for me, not in this car. It's just way too modern, looks a bit ricey in the Porker. On the plus side, they're even brighter to the eye than the white, and really show up well even during the day. These LEDs (white or blue) would definitely be the cure for dim dash illumination! The biggest PITA in the install is just getting access to the bulb sockets, not so much the install. Though I will note, the bulbs are polarized, only work one way in the socket (this is clearly noted on the packaging, no worry). So you have to make sure you've got each one installed the right way 'round before putting the dash back.

So I'll be ordering up some more to finish off the rest of the dash in white, as well as some more for my wife's car; she has a WRX, rally blue of course, so once we confirm fitment she'll be getting a blue dome light replacement (I already got one, but in white, my error), another white bulb for the second map light, and some single LEDs to rig up as overhead internal lights (go on with dash illum, sort of ambient lighting as seen in newer cars, lighting up the center stack area).
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Vaughan Scott
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'79 924 #77 SCCA H Prod racecar
'82 931 Plat. Silver
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pocketscience · Posted: Sat Jul 21, 2007 10:47 am Post subject:

I was just shopping around last night for the exact same gear. I've got the dome light on order, and was still trying to figure out the instrument lights. I found some of the twist-lock style on another site, but I'll take a look at the site you mention too!

Thanks for sharing,
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endwrench · Joined: 07 Dec 2002 Posts: 1631 Location: Victor, Montana

Nice stuff. I'll definetly consider this rout as I think the stock lighting sucks. At some time in the distant futire I would like to build a custom center counsel and intergrate some of your ideas. I was always a little concerned if LED's could be dimmed but your link says it is not a problem. Thanks,

Todd
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'79 924NA. Rebuilt 9.5:1, MSDS header, Mega Squirt Injection, MJLJ-EDIS Ignition, 1.6L Whipple Charger and Intercooler, 10lbs Boost, 944 Trans, Custom HD Clutch.
"simsport" said....superchargers are better than turbos its official!....

!tom · Posted: Sat Jul 21, 2007 3:11 pm Post subject:

LEDs can be dimmed in a much more controlled fashion than incandescent bulbs. However, you may need to add a load resistor to the circuit if you want to use your original dimmer knob. Either that, or it would just take some simple re-wiring of your original knob if your new lights don't provide a sufficient load to dim all the way.
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924RACR · Posted: Sat Jul 21, 2007 10:05 pm Post subject:

I do not find that the LED's, plugged in for stock bulbs, dim very much. Yes, they do, but not as much as the link would seem to indicate.

Doesn't really bother me, I only ever drive in the city these days, hell I don't even drive that much at night!

I think the color selection provides a major impact on the perceived illumination, and so is more significant... might choose red instead of white if I did need to drive in the country...
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Vaughan Scott
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'79 924 #77 SCCA H Prod racecar
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#25 Hidari Firefly P2 sports prototype

morghen · Joined: 21 Jan 2005 Posts: 9080 Location: Romania

yea well very nice but you know the board....nobody believes you until you post pictures.

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924RACR · Posted: Sun Jul 22, 2007 10:23 pm Post subject:

I've played with these some more, including finally a chance to drive in dim, if not full dark, conditions. And I've definitely changed my opinion. Still like the dome light as is, no complaints.

For the dash lights, however, I'm starting to lean towards the blue - it's just so much more visible. The white, while I prefer the color maybe, doesn't seem anymore to be a drastic improvement over the stock incandescents. It's just a nicer, cleaner, more modern look than gauges lit in yellow.

I'm gonna give it a bit more time, try and take these things for another spin under true night conditions, but I'm now leaning towards getting blue lights. Plus, since this car (the 82) is going to be modified quite a bit, maintaining stock looks isn't a high priority any more.

Also, on the dimming - OK, yes, I can see it now, and I take back what I said, they do dim pretty well, about the same as the stock bulbs. I can see it more clearly in my wife's car dome light, which dims the interior bulb after you close the door - it definitely fades out.
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Vaughan Scott
Webmeister
'79 924 #77 SCCA H Prod racecar
'82 931 Plat. Silver
#25 Hidari Firefly P2 sports prototype

!tom · Posted: Mon Jul 23, 2007 9:30 am Post subject:

If you want your LED dash lights to dim more than they do now, put a resistor in parallel with the dimmer circuit.

The idea is to increase the current draw of the LED circuit to match the current draw of the incandescent bulbs. Since I don't know what current draw you have now vs. what you had before, I can't recommend a resistor. If I knew those numbers, then I could.
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Druman · Joined: 19 Mar 2007 Posts: 419 Location: Middleport, Ohio

Probably a 100k, just a guess.

7osh
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dgz924s · Joined: 03 Nov 2002 Posts: 592 Location: Kansas

How much HP was gained?!!

....Ok will this be the same as the 924S pods? I assume so being an early dash but helps to ask as every year something changes, would not doubt the lighting system was tweeked as well!

Proceedural writeup too please!!

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924RACR · Posted: Tue Jul 24, 2007 12:27 am Post subject:

LOL! Well, mine's an early '82, so it's pretty similar; IIRC the earlier combo gauges didn't have the little twist bulb sockets, only the same as the speedo and tach. YMMV!

The biggest PITA is getting at the backside of the gauges; you can either pop them out individually from the 3-pod cluster, or pull the whole cluster. Center gauge stack is pretty obvious; two screws at the top, then pop/snap out.

The actual procedure to change the bulbs? How many 924 geeks does it take to change a lightbulb?? Really, just unplug the old one, plug in the LED, give it a ground and check to ensure it lights up (since they're polarized, as mentioned, if inserted backwards they won't light up), then stick the bulb holder back in the gauge. It's really simple.

There's some other bulbs in there you may wish to change, in addition to the 8 or so for the gauges themselves. There's one in the headlight switch, IIRC, and then there's 2 or so in the center console below the gauges, to light up the HVAC controls. There's also one in the ashtray; this however would require a different bulb than the LED 74 type, because even though the fitment is the same, the light needs to come out the side to illuminate the ashtray. These 74 single-LED bulbs have light focused in a somewhat narrow cone coming out the end (which is perfect for the gauges).
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Webmeister
'79 924 #77 SCCA H Prod racecar
'82 931 Plat. Silver
#25 Hidari Firefly P2 sports prototype

dgz924s · Joined: 03 Nov 2002 Posts: 592 Location: Kansas

I agree on changing a light bulb but then you were not born in Iowa!!

My pod is EZ to remove so there must be some differences thus prompted the write up request. Only 3 bulbs in my pods, one for the cabin and one for the butt tray. Hummm need to do inventory on what is really lurking behind the gauges!

Thanks!
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Dal Glassinger

924RACR · Posted: Tue Jul 24, 2007 10:30 pm Post subject:

My lack of EX removal is complicated by a poor-fitting dash cover.

I do now have pics that show the difference in illumination pretty well, but can't get to my website to upload (server maintenance, I think) so will be a wait, unless you're rennlist members - think I can upload the pics there.

EDIT - here's the rennlist thread with pics:
http://forums.rennlist.com/rennforums/showthread.php?t=366295
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Vaughan Scott
Webmeister
'79 924 #77 SCCA H Prod racecar
'82 931 Plat. Silver
#25 Hidari Firefly P2 sports prototype

dgz924s · Joined: 03 Nov 2002 Posts: 592 Location: Kansas

Photo is not one of Ansel Adams best but looks really sweet! I kinda like the 2 color deal. I could care less about the speedo, cops will tell me when I am driving too fast,

but the tach I would like to see better. I think the blue is cool but agree with your opinion, I guess it would be one of those things you have to "try on" first to get a good feel for the blue lights. But it all has to wait until I see how this new modified head is going to work out first, I guess I had better get busy huh!

Thanks!
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morghen · Joined: 21 Jan 2005 Posts: 9080 Location: Romania

someone post the pictures on 924board too pls...i dont have a rennlist username so i cant see the pictures.
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