Dodging SUVs >> Improved LED tail and brake lights
 

Had another close call with a SUV almost rear-ending me. This is the second time an Escalade yuppie, with cell phone in one hand and latte in the other, looked over/beyond me until it was almost too late.

I had to do something to increase my visibility. I ordered the brightest (red) LX-5 LED bulbs from www.superbrightleds.com to replace the tail/brake light and third stop light. The LED bulbs are a better fit than standard bulbs (the socket is 0.5 mm wider) and what a difference these make! Quality of manufacturing was surprisingly very good and I hope these will last years as LEDs should.

I measured almost a 20% increase in light output (using a Minolta IIIF light-meter). The visibility is greatly improved. The standard bulbs have a hot-spot in the center with uneven light distribution, these evenly fill the housing with bright light (like European rear fog lights).

I can recommend these to anybody concerned with being rear-ended. I tried to capture the difference photographically and will try to attach the image.

The photograph does not do it justice but you can see the diff. http://forums.pelicanparts.com/uploa...1216604094.jpg

LED LX5 bulb in aluminum housing next to standard bulb. http://forums.pelicanparts.com/uploa...1216604402.jpg

They have some great products.

I have replaced the blinkers on a couple Dual-Sport blkes with good results, the only thing I had to change was the relay to a low load relay.

Does that also need to be replaced on the Porsche?

Dave

I did not change the blinkers as being noticed (brake lights) was my number 1 priority. I am tempted to upgrade the rest and assume that it requires a new relay.

Shouldn't the LED's be more efficient and not require a new relay

Are you replacing the stock white bulb with a red LED one?

I believe you need a load relay since the resistance is less in the LED bulbs (when compared to a non LED bulb). You will need them in turn signals (blinkers) also or you will get "ricer" flashing or the bulbs blink really quick like when there is a burnt out bulb.

On my bikes the blinkers just stayed on (Bright).

Ordered there Electronic LED flasher and was good to go!

Now you have me thinking about changing out the Porsche bulbs with LED's. They should last my lifetime.

Dave

What are the part numbers for all the bits you ordered for the brake light swap?
Simon

Yes, you are supposed to replace the bulb with a LED that matches the color of the lens.

For my apllication, it was two 1157-RLX5 for the tail/brake lights and one 1156-RLX5 for the third brake light. Their cross reference guide is good.

Fight fire with fire. My third brake lamp from the rear roof of a Denali SUV, mounted upside down on the tail:

http://img.photobucket.com/albums/v6...e3rdlight2.jpg

http://img.photobucket.com/albums/v6...aillights2.jpg

Originality? To each his own, not my taste!

Oh, not to worry. There ain't one part on my car that is original...CW's blood pressure rises whenever I show up.

http://img.photobucket.com/albums/v6...orscheGT21.jpg

Watch the flasher type closely until you are sure they work properly...and check regularly. I had an LED in my enduro M/C. I don’t know if it was the vibration from the thumper engine but the bulb didn't last long. It was a dual element (AC 1157?) flasher bulb that glowed all the time but flashed when the brakes were applied. I think the circuitry failed. They worked OK for a few months but eventually the flashing unit failed.

3rd brake light---how is it mounted on your '87? My '86 is high inside rear window. I wonder if the bulb socket 'orients' the LED's to point rear-wards.

Good idea, but I think you'll find even faster brake light response by replacing the existing master cylinder brake light switches with another type switch. The hydraulic switches are not adjustable; they only complete the circuit at a certain brake pressure theshold. IOW, light braking may not energize even the most advanced LED light bulbs because of the slow response MC switches.

Sherwood

Just get straight pipes, everyone notices flames shooting out on shifts....:)

General info:

Old type flasher relays are thermally actuated: one of the internal contact elements heats up from the resistance to current in the circuit, disconnects, cools, reconnects - over and over.

When you reduce the bulbs resistance by switching to LED, you allow the current to "flow faster" in the circuit which heats up the thermal contact faster in the flasher relay. This is why switching to LED bulbs in older cars results in a fast flash rate.

Switch your flasher relay to an electronic type and the problem is solved.