Taillight Conversion from 1157 to 3157 bulb with Photos

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CadChris
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Joined: Sun May 16, 2021 3:52 pm

Re: Taillight Conversion from 1157 to 3157 bulb with Photos

Post by CadChris »

Sorry for the double post......I added additional info in the last paragraph above on LED's......
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tgreese
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Re: Taillight Conversion from 1157 to 3157 bulb with Photos

Post by tgreese »

It's an issue with the forum. Click submit once and a single copy will eventually show up.
Tim Reese
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CadChris
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Re: Taillight Conversion from 1157 to 3157 bulb with Photos

Post by CadChris »

That bulb has been discussed heavily and not recommended to be safe by the experts on the Candlepowerforums. Just saying. It's a halogen bulb, runs way too hot, high amp draw on original wiring at 3.9 amp draw, and can melt wires. Probably your buckets are made out of metal, but could melt the lens if sitting on the brake pedal for a while and/or melt wires in the worst scenario. Most likely the "rise-time" is very slow which at high-way speeds is really delayed before coming up to full brightness if you land-on the brakes. This bulb probably causes a 1/4 sec. delay which is probably 15' of response time for the driver behind you to react! They have a formula on the Candlepowerforums they refer to all the time which the LED bulbs are instant-on and prevent this delay. Like I mentioned, they only recommend the Sylvania ZEVO's but you must do a remedial evaluation at all viewing angles/distance to see if the LED retrofit brightness falls-out at different viewing angles.

But on those H1157 bulbs, those experts also said the filaments are not precisionally nor properly placed in the correct locations according to the specs of a 1157 Bay15d style bulb which I guess throws-off the focusing for the reflector bucket. I always wondered how much precision is needed with a parabolic reflector going thru a lens with focusing optics, but those guys are the lighting engineering experts and know their photometry. That's why they recommend the HONDA 3496 bulb as the best upgrade in place of any 1157/2057/2357 bulb since it was such an advanced designed bulb from Stanley of Japan. I guess it also has a much lower amp-draw (faster rise-time) vs. a conventional 1157 bulb. I've been personally researching amber bulb paints to make a Honda 3496 amber to be used for front -signals in my car since the Honda bulb is only available in clear......

Probably to get the most out of that H1157 halogen bulb, it's best to run new heavy gauge wiring to the rear-lamps thru a good TYCO/Bosch relay so full amperage is not going thru the factory headlamp switch which might not able to carry a heavy load of 8amps for a long period of time if someone is sitting in traffic on the brakes for a while.......

Triumph215
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Re: Taillight Conversion from 1157 to 3157 bulb with Photos

Post by Triumph215 »

I haven't made it to dim tail light bulbs yet but they are on my TTD list and will use this when the time comes.
Thanks !
1964 Triumph TR4 with 1964 Olds 215 heart transplant
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Hobart
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Re: Taillight Conversion from 1157 to 3157 bulb with Photos

Post by Hobart »

Great info here! Thanks to all!
Bill

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1959 Bel Air
1968 Nova
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Nikkormat
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Re: Taillight Conversion from 1157 to 3157 bulb with Photos

Post by Nikkormat »

Thank you CadChris!!
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CadChris
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Joined: Sun May 16, 2021 3:52 pm

Re: Taillight Conversion from 1157 to 3157 bulb with Photos

Post by CadChris »

Glad I can help ya' all........
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