Bizman928

I am in the midlands -Uttoxeter near Derby and the JCB digger factory HQ.
You are more than welcome anytime or I can meet you half way if you were traveling around the other end of the UK.

Steve

Wipeout

Hmmm. H4 LEDs...my curiosity from the 944 side has been piqued...

jcorenman

I think PET is the only "official" document. But it is pretty simple.

For the '87+ 928s there are two basic headlight assemblies:

1. USA/Canada, DOT-approved lights with H5 (9004) bulbs, part# 928 631 135 00 MSRP $428
2. ROW (rest-of-world), much better lights with H4 bulbs. These come in two flavors:
   • Left-hand drive (928 631 101 03, MSRP $355 in the states)
   • Right-hand drive (928 631 102 01)

The DOT-approved H5's have the three DOT-required aiming "nibs" on the face. The H4's have a flat face with "H4" embossed into the glass.

Those part numbers are the complete headlight assembles. Each can be fitted with different wattage bulbs, or aftermarket HID or LED light sources.

The optics for the H5 (USA) lights are not very good (low-beam pattern is poorly defined) and increasing brightness also increases glare to oncoming traffic. This is not a concern on a highway, but an issue on narrow country lanes.

The H4 optics are characterized by a sharp upper cutoff to minimize glare to oncoming traffic, with an extra wedge of light towards the right (or left) to light up the critters poised at the edge of the road.

Increasing brightness for the H4s has great benefit without appreciably increasing glare. Stock H4 bulbs are typically 55w, and are available in various wattages. Above stock wattage however, both heat and wiring become an increasing concern.

Which is why the new LED lights are so attractive: More light with less heat. The geometry of the light source itself is important to make the H4 optics (reflector and lens) work as intended, and the small size of the LED chip is an important part of that.

Cheers, Jim

Bizman928

Yes these will fit the 944 as well. We have a couple of customers fitting them over Xmas & New Year period who will be taking photos so will post them once I get them for the 944.

Thanks
Steve

Tony

So...in a nutshell..for all of us following along.. the best headlight set up then is ditching the stock US H5 lenses/bulbs/ and going with the ROW H4 "glass" and these LED bulbs....and the ROW H4 glass is very hard to come across here in the States.

Is a swap as simple as taking a H4 RH glass set up and swapping sides on the car for a LH drive application...as the beams will be directed by the pattern in the lense accordingling to the side of the road of the country they are meant for.

Rob Edwards

Assuming they're still available new from Porsche , they're not _hard_ to get at all, just expensive. I bought a new pair in January 2013, they were $250 each. Guess they're incrementally more now?

Rob Edwards

No, the RHD lenses will not work in the US at all, unless the goal is to **** off everyone coming towards you. For the U.S. you need two identical LHD lenses. I made this dumb mistake a couple of years ago when working on Dan Hebert's car, bought 1 LHD and 1 RHD. Ended up buying a 2nd RHD unit and sold the pair to a RLer in New Zealand.

Tony

Im pretty sure i can get a set of RHD H4 assemeblys pretty easily. My concern is the pattern in the glass is specific to a RHD car...(or am i wrong)??

It would seem simple enough to swap the assemblys from side to side so the beam is projected correctly for a LHD country. ..but nothing is ever simple is it.

I honestly do know squat about the lense bulb configurations..this thread has been a great help with what Jim posted earlier. I would like to upgrade my headlights though.

Rob Edwards

Don't do it. Reason(s) why outlined below:

https://rennlist.com/forums/928-foru...-into-lhd.html

Tony

good stuff..thanks
Learn from the lessons of others!

uncre8tv

Thanks Jim, that's the decoder I needed. (and I know the nibs are there without even having to go out and check. H5 glass for sure.)

ramcram

Hi Speedtoys,
It most certainly is easier than HID. I converted my stock ROW '86S to Steve's Cree LED and was very pleased with the result. Then my other ROW '86S, with HID lights that I fitted a couple of years ago, lost one and I could no longer find the manufacturer. So I ripped out all the HID stuff [cost boo hoo], and fitted a second set of Cree LEDs. far superior.

Chalkboss

Thanks Jim for that very precise explanation! You boiled it down for me.

bogdann

Thanks Steve. I am happy to buy off Roger when I get the set for my 86 if he will be selling H7's or direct from you. The lights in the std Touareg were a big disappointment. Drove a mates late 60's VW fastback and those lights were the best std I have driven with and we don't seem to have progressed much at all in the Hellas.

Will be in contact.

sstrickstein

Althought they may be only the 7" design for the housing, the light output, simplicity of installation, lack of wiring problems for the price is what sold me. I've run the Truck-lite for 2 years without a single problem. Playing with the wiring on a 30 year old car didn't appeal to me.