LED conversion -- highs, lows, and relay swapping

[dicklague]

I have been doing some work on electronic LED compatible flashers for the 911. In my 1973 the stock flasher is a 4 pin and I did convert it for use with a 3 pin LED flasher.

CLICKCLACKBOOM started this thread and I took his suggestions and they work.

Quick summary is that the 4 pin has an extra set of flasher contacts that really not necessary at all. As a matter of fact the Porsche wiring is a bit puzzling and unnecessary complicated.

LED conversion

the 3 pin conversion is easy and then you can get an LED compatible 3 pin flasher. Mine even has a variable flash control.

[Spenny_b]

Originally Posted by Jack Olsen

......I've been thinking about doing something like that with the front buckets. They've gotten so expensive though, that I'm a little cautious about cutting a set up.

Maybe another aluminum box for me?

Hey Jack, hope you're well?

It'd be a big piece, but with the ever reducing cost of 3D printing rigs, it may be worth investigating?...nice n light

Talking of weight saving, if you've not seen it already, Roland (proffighter) is engineering some fantastic lightweight pieces on his 930 project --->

Another Rust Combat

Cheers
Spencer

[JeremyD]

Just a FYI

Rothsport has these available now

Welcome to Rothsport Racing - Products

[Elombard]

Wow I have been waiting for those and then....$500.....argh cannot justify. Going to have to make my own.

[quattrorunner]

Here is the front impact bumper car marker light converted.





I installed iroc bumpers and had to loose one light and wanted to upgrade. This was way too simple to do. Took 10 minutes and looks great in use. I used some leds I got on ebay, the block with two I use for the marker lights and the two little round ones are brighter and use them for the signal. With the reflector inside it works great.
I already had the flasher upgrade so that was not an issue for mew.

[jpnovak]

What were the LED "pucks" listed as on ebay.

[quattrorunner]

The round ones are eagle eye drl lights. In 4 and 10w sizes. The block one is just a drl day time running light. Can't remember much about that one. I've had them for a while.
If I were to do it again I'dahe sure the blinkers were more level because the markers flip flop side to side. Looks odd.

[quattrorunner]

[otto in norway]

I finally finished the DIY of the lightweight rear LED lights. Thought I'd upload some pics.
Worked out well, even though the LED pads are E-bay cheap-stuff. No issues with turn signal blinker, probably because the front is untouched.

Some pics:

Ready on the bench.


Installed and testing without lense.


Testing with lense on, a little strong driving light.


And finally a shot with indicator on.


After these pictures werre taken I adsjusted the strength down a little bit for the driving lights, and it was spot on. Notice that I have two LED pads working together for both driving lights and for brake light. The intensity for brake light is about the stock brightness. I kept the indicators as strong as they seem there. After all they are difficult to see from odd angles, wich is likely for those lights.

[Jonny H]

I don't really know how to start this reply so I'll dive straight in. I think you are all playing a dangerous game swapping in cheap led panels into your light units! LEDs have many characteristics that need to be accounted for in the design of the drive circuitry.

Simply plugging them in and seeing that they light up doesn't even come close to assessing suitability for road use. Electronic engineers (like me) spend hundreds of hours designing circuits to tame the heat, voltage variations, damp, vibration and other 'variables' that the environment throws at our creations before we even get close to a prototype. We then undertake extensive and exhaustive testing of our prototypes and then have to meet many approvals before we can launch a product. There are very good reasons we do this, safety being number one, durability a close second.

Put it this way, if I gave you a set of unknown wheel nuts that fitted your car would you be comfortable with taking it for a high speed run? You'd probably want to know the material, how many threads it has etc. If they look ok, they must be ok right? What if I then said they were off my wheelbarrow?

I worry that your homemade lights will 'work' in the garage and be given the ok. Then during a cold winter or indeed a hot summer, or when a solder joint fails due to vibration, or damp enters the circuit, or when the battery is slightly flat or the voltage regulator spikes your LEDs will fail and you will be rear ended. The person who hit you will claim no tail lights and the assessor will find your non approved creations. A bit dramatic perhaps but you get my point.

Not trying to poop on this thread but be safe people!

Here is the simplest article I could find to give you an insight on the technical challenges of driving LEDs properly:

http://www.ledsmagazine.com/articles/print/volume-4/issue-8/features/driving-led-lamps-some-simple-design-guidelines.html

[proffighter]

Are those builds legal in US?

[Jnduda]

For what it's worth I use the plastic part below that is both light and has held up on the track for years.

Indicator Unit Housing Rear (Plastic). Porsche 911 1970-89 (OE Ref: 91163193900, 91163194000) - 9116319 | Design 911

[proffighter]

Originally Posted by Jnduda

For what it's worth I use the plastic part below that is both light and has held up on the track for years.

Indicator Unit Housing Rear (Plastic). Porsche 911 1970-89 (OE Ref: 91163193900, 91163194000) - 9116319 | Design 911

I have them too, not in use yet, but here (scoll down) some details about:

Another rust combat

[javadog]

Originally Posted by proffighter

Are those builds legal in US?

No, not really. We just have nobody inspecting the cars, or policing the rules.

JR

[otto in norway]

Originally Posted by Jonny H

I don't really know how to start this reply so I'll dive straight in. I think you are all playing a dangerous game swapping in cheap led panels into your light units! LEDs have many characteristics that need to be accounted for in the design of the drive circuitry.

Simply plugging them in and seeing that they light up doesn't even come close to assessing suitability for road use. Electronic engineers (like me) spend hundreds of hours designing circuits to tame the heat, voltage variations, damp, vibration and other 'variables' that the environment throws at our creations before we even get close to a prototype. We then undertake extensive and exhaustive testing of our prototypes and then have to meet many approvals before we can launch a product. There are very good reasons we do this, safety being number one, durability a close second.

Put it this way, if I gave you a set of unknown wheel nuts that fitted your car would you be comfortable with taking it for a high speed run? You'd probably want to know the material, how many threads it has etc. If they look ok, they must be ok right? What if I then said they were off my wheelbarrow?

I worry that your homemade lights will 'work' in the garage and be given the ok. Then during a cold winter or indeed a hot summer, or when a solder joint fails due to vibration, or damp enters the circuit, or when the battery is slightly flat or the voltage regulator spikes your LEDs will fail and you will be rear ended. The person who hit you will claim no tail lights and the assessor will find your non approved creations. A bit dramatic perhaps but you get my point.

Not trying to poop on this thread but be safe people!

Here is the simplest article I could find to give you an insight on the technical challenges of driving LEDs properly:

Driving LED lamps – some simple design guidelines - LEDs

Thanks for bringing that up!

It is true that you should always use caution when doing any modification to your car. I would never attempt to to anything like this if I didn't know electronics like I do. I probably wouldn't even come to think of the idea even. But since electronics is my profession I have no problems doing this mod. And this is no rocket sience. By the way, the LED pads I use do not require any driver. It is just a grid of LEDS on a board with a resistor in series to control the voltage/current. That's the way I am able to "dim" them too, by use of an external resistor.
I think that doing work on the brakes myself is more "scary", although this is completely legal and in the realm of any home mechanic. The consequences are huge if anything is not right with the installment.

So be safe, -absolutely. Make sure you test properly and that you know what you are doing. And in this case, make sure that you keep an eye on that the lights in fact are working regularly, like you should do anyway. Remember; a normal bulb is'nt exactly bulletproof either.

[Jack Olsen]

And while I'm not an engineer of any kind, I used a manufactured (and approved for road use) set of lights that were designed for universal 12V applications and a boat trailer. In terms of weather-proof-ness, they're designed to be submerged in saltwater.

But I would agree that caution is in order for any modification that an owner is doing that could decrease safety.

[Jonny H]

Jack, it's the ebay specials that are more of a concern. IMO, they are no more fit for purpose than Christmas tree lights.

Ok. So I may have a thing about LEDs, here's why....

My company developed the multi colour cabin lighting for the Airbus A380 super jumbo where we learnt that LEDs are not just 'little lights'. It is an extreme example but thought I'd share to give you an insight. Maintaining a controlled light output required a hybrid constant current / PWM drive circuit. The requirement is that the lights should maintain the same output level for 30 years. This also meant that brand new replacement units can be placed alongside potentially 30 year old units and be exactly the same colour and intensity. We worked with the LED manufacturers to derive the predicted fade profile for 30 years. This profile is different for different colours (we were using red, green, blue and amber). A microprocessor records the instaneous drive current dependent on intensity and colour demanded along with the elapsed time that each led had been run for. This is used along with measured temperature to correct the drive intensity according to the fade profile. Essentially, new units are underdriven and old units are overdriven to give the same output. Each unit is setup and calibrated using a colour light meter and conforms with the standard CIE colour gamut chart. The project took 5 engineers 18 months to complete.

If you've seen the sunrise / sunset cabin effect on the plane, that's the result of a lot of hard graft!

[mean_in_green]

Saw it a few months back - it's impressive Jonny.