Pathetic Headlights

Technical questions and answers about the Mazda Bongo

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bigdaddycain
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Re: Pathetic Headlights

Post by bigdaddycain » Tue Jul 28, 2009 12:15 am

Eyebrow grille looks good though! :wink:
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M 80NGD
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Re: Pathetic Headlights

Post by M 80NGD » Tue Jul 28, 2009 12:23 am

bigdaddycain wrote:Eyebrow grille looks good though! :wink:
Honestly Ste,the only reason I've not changed the poor bulbs is,I thought I had to take the grille off!! :shock: When of

course,I had to remove the grill to replace my illegal Japanese fitted,sidelight bulbs! :shock: #-o Cars up for sale now!!
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Ron Miel
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Re: Pathetic Headlights

Post by Ron Miel » Tue Jul 28, 2009 12:32 am

bigdaddycain wrote:I thought the "super brilliance" bulbs that Halfords(?) sell are brighter because of a different gas used in the bulb? Aren't they still 55watts, so same heat output? I'm just guessing here, i don't actually know.

I'm on the new shape lights too, and i have "all weather" 55 watt bulbs fitted, they give a yellowish glow (which i actually like) But they seem brighter than standard bulbs, and don't seem to throw out any more heat than standards...
Thanks. 55 watts in, with more lumens out, is apparently achieved by "running the filaments harder", made possible by surrounding them with an "improved" gas - but it is still the filament emitting the increased light energy. That much is confirmed in the published data on higher brilliance bulbs.

None of the manufacturers confirms whether or not that also causes more filament heat emission but I think that it must do so. If the lamps aren't hotter on the outside, I'm guessing that it must actually work by the "improved" gas (and tougher quartz glass used) actively reducing heat transmission inside, and heat loss from, the bulb. After an initial warm up that would keep the gas temperature higher immediately around the filament, then enabling the same 55 watts of electrical energy input to maintain a hotter, brighter, filament. If that's right, you might see a perceptible short delay in reaching maximum brilliance after switch on - or a higher power input, until stabilising at 55 watts.

Do your new shape headlights also have the cup shaped shields (heat shield, light shield, or both?) in front of the bulbs, as mine do above? Cheers.
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bigdaddycain
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Re: Pathetic Headlights

Post by bigdaddycain » Tue Jul 28, 2009 1:02 am

Hi Dave, yes, mine has the internal heat shields also... Though i'm not 100% certain they actually are heat shields, i think they may be to shield the direct light from the bulb from oncoming traffic? Perhaps the onus of light transmission from the lamps is relied upon by the superior reflector of the new shape lamps? If you notice the new shape lamps lens is of a much clearer design than the old type bongo lamps,perhaps there was an issue with glare with new shape lamps because of the clearer type lens? Hence (what i suspect) is a light refractor as opposed to a heat shield. Just conjecture of course....
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Ron Miel
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Re: Pathetic Headlights

Post by Ron Miel » Tue Jul 28, 2009 1:33 am

bigdaddycain wrote:Hi Dave, yes, mine has the internal heat shields also... Though i'm not 100% certain they actually are heat shields, i think they may be to shield the direct light from the bulb from oncoming traffic? Perhaps the onus of light transmission from the lamps is relied upon by the superior reflector of the new shape lamps? If you notice the new shape lamps lens is of a much clearer design than the old type bongo lamps,perhaps there was an issue with glare with new shape lamps because of the clearer type lens? Hence (what i suspect) is a light refractor as opposed to a heat shield. Just conjecture of course....
Hi BDC. I guessed heat shields in the first place as there seemingly had been some cases of lens yellowing, as well as the yellow glare reduction films mentioned earlier. If your brighter bulbs are not heating up the lens or the surrounding headlight structure, I'm sure you're right and they're just there to reduce glare. So, I'll get on with it but, on reflection (pun not intended :) ), I think I'll fit some Philips plus 50s, rather than the probably somewhat OTT Ring Xenon Max +90s. I do think that even the new shape Bongo headlights are a bit below par with standard bulbs. Cheers and thanks again for inputs, David
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Ron Miel
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Re: Pathetic Headlights

Post by Ron Miel » Sat Aug 01, 2009 12:12 am

Ron Miel wrote:
bigdaddycain wrote:Hi Dave, yes, mine has the internal heat shields also... Though i'm not 100% certain they actually are heat shields, i think they may be to shield the direct light from the bulb from oncoming traffic? Perhaps the onus of light transmission from the lamps is relied upon by the superior reflector of the new shape lamps? If you notice the new shape lamps lens is of a much clearer design than the old type bongo lamps,perhaps there was an issue with glare with new shape lamps because of the clearer type lens? Hence (what i suspect) is a light refractor as opposed to a heat shield. Just conjecture of course....
Hi BDC. I guessed heat shields in the first place as there seemingly had been some cases of lens yellowing, as well as the yellow glare reduction films mentioned earlier. If your brighter bulbs are not heating up the lens or the surrounding headlight structure, I'm sure you're right and they're just there to reduce glare. So, I'll get on with it but, on reflection (pun not intended :) ), I think I'll fit some Philips plus 50s, rather than the probably somewhat OTT Ring Xenon Max +90s. I do think that even the new shape Bongo headlights are a bit below par with standard bulbs. Cheers and thanks again for inputs, David
Philip VisionPlus (+ 50% illumination) H4's have done the trick brilliantly, in both senses. Now I've got them, I can see the heat ouput spec on the packaging for the first time. The outer surface of the glass reaches a temperature in excess of 200C after 5 minutes running. Not sure how that compares with standard bulbs but a temperature anywhere near that would suggest that the gizmos in our headlights ARE heat shields. Compared with many, more streamlined, modern headlight designs, the plastic lenses in the Bongo are pretty close to those hot bulbs, so heat shielding seems a logical step if resulting problems have been encountered in earlier production. Anyway, can recommend the VisionPlus bulbs, available at http://www.autobulbsdirect.co.uk/h4-phi ... 16322.html at £18.06 - the "Special Offer" referred to means BOGOF, so it's £9.03 per H4 pair, with free delivery.
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