sharknoob

+1 on the Cibies I picked up a set in the late 70s. The same lights have been in 10 or so cars/trucks and a couple motorcycles. I buy cheap sealed beam lights when I sell and stick them in. This year I took them out of 944 to put in to the 928. Looks like they sat to long with some moisture in them and started to rust and bubble the reflector. I guess over 30 years I got my money out of them.

I had a set of Hella H4s in the garage since the late 80s I put them in the 928 instead. I would say the Hella lights are a close second.

M. Requin

Mark, this is just the approach I want to take - stock look for my 86.5 but better light. How much did you have to change the harness?

ACG

H4 is definately an improvement over the original sealed beam.... regardless of whether they are 7" or 8" H4s. This is where I bought my 7" Hella E-code lenses (not affliated to seller):

http://www.rennbay.com/ecode-hella-h...3dc47561db6310

I like the H4 E-code beam pattern has it provides a sharper beam cut-off definition.

The Rennbay H4s is a simple swap on my 84(i.e., remove headlight bucket cover, chrome ring, remove mounting screws, disconnect rubber harness plug, swap new headlight assembly.... and connect harness plug ... and install in reverse steps). I recollect someone mention the earlier models involve a simple swap as it comes with a rubber harness plug (different case with the H5s?)

shmark

I didn't have to change a thing, literally plug and play, no wiring upgrades necessary or additional relays because I'm using stock wattage. He talked me out of higher wattage because the difference is really minimal compared to a good lens/reflector combination. In his opinion the pursuit of higher wattage is to compensate for inferior lamp design. Took all of 20 minutes or so to install. I emailed Daniel back and forth with questions and he gave me a ton of great information, made it easy and the parts he sent were perfect. Check his site out for a lot of great information on lens/reflector design, he's done a lot of work. In his estimation the Cibies are the best, with Hella pretty good too. All I can say is the Cibies with the stock wattage bulbs are incredible. No affiliation, just a satisfied customer.

M. Requin

Hey Jeff, apologies for at least partially highjacking your thread! And Mark. thanks also- just what I needed to know.

Don Carter

Great timing on this thread. I too am considering upgrading my original headlights on my 86.5. I had already found the rennbay lenses, and was planning on the 7" ecodes, keeping the chrome ring. The only question I have is does the 80/100 bulb plug right in, or is it a different plug that has to be spliced in? I also want a whiter color and from Alan's post, it sounds like the Silverstars will give me that.

sharknoob

One more thing when you hit the high beams on the Cibies you will wonder how the hell they do that beam pattern... They are one of the few things that are worth the price

6mil928

What about H4's do they come with 928 specific mounts or do you reuse the sealed beam mounting?

ROG100

I sell the 7" H4's for $50 each. Just checked with my other supplier and even cheaper.
Just put a set on my 78 and well impressed.
Not sealed beam and not DOT legal 8>) - be aware there are DOT legal 7" H4's and they are not good.
Plug and play

Don Carter

Roger, what brand of lens can you get? Do you have access to the 80/100 bulbs as well? Do you know if they plug in to the existing sockets?

auzivision

What's the goping rate for 8" H4's?

ROG100

I stock the 80/100W H4 bulbs for $11.95 ea.
The lights are Hella and they are similar to the Cibie.
Plug and play.

8" H4's are only available direct from Porsche and at $320 each very expensive.
8" H5's are even more expensive at $384 each.

jcb928

How much brighter would the Hella Yellow Star H4 Bulbs 130/90W be?

dr bob

There's a diminishing return on the higher wattage bulbs. Start with the original bulbs first The higher wattage bulbs need bigger wiring and dedicated relays. There's a big voltage drop with the higher current so they heat up your wiring instead of putting out full light intensity.

SharkSkin

I think 100W is about the limit for stock wiring, assuming perfect condition and no flakey connections. I went from 7" Bosch H4 E-code to 8" Bosch H4 E-code and noticed a significant improvement in the quantity, quality and distribution of light. Some of this must have been due to newer bulbs, reflectors, etc. but it's a well-known fact that a larger reflector makes a difference too.

If you assume that the reflectors are flat circles with 2" holes in the center for the bulbs, OD of the circles @ 6" and 7", you get the following surface area calcs:

7" nominal, 6" reflector: 28.25 sq. in - 3.14 from center = 25.12 sq. in.
8" nominal, 7" reflector: 38.47 sq. in - 3.14 from center = 35.33 sq. in.

Based on the above, the 8" has 140% the surface area of the 7", you might find there is a bigger difference if you took the trouble to measure and calculate the properties of the paraboloid and its reflecting surface area. However bad these estimates may be, it's clear that the 8" offer a lot more surface area. IMHO if you find 100W in 7" is not enough for you, you may find that 100W in 8" is plenty.