Re: 9004 - 9007 Conv

[Luis Marques <marques@rtis.ray.com>]

Todd Phenneger <phen9461@uidaho.edu> wrote:

> I have heard that this conversion makes a noticable increase in light
> output on the 4kq.  I am relaying my lights on my girlfriends 87' 4kq
> and wonder if I should do this at the same time.
>
>     As I understand it from past posts, I need to swap the Hi/Low beam
> wires since they are opposite of each other in the two applications.

You need to swap the low beam and ground wires (the green and yellow
ones).

>     I also need to grind off a prong to make it fit?  Is this prong on
> the light housing itself  or on the bulb base?  Which one is it?

You need to either gring off two new channels on the plastic base of the
9007 bulbs to match those of the 9004 bulbs, or grind off two tabs in
the headlamp socket so that it will take either one of the bulbs.  The
flat portion of the bulb pastic base should face up.

>     Why does this work, is the 9007 a better bulb, or is it just a
> fluke that it works better in this application?  ie, would it work
> better in a Subaru or a 5ktq, or a 5k, etc.

It is kind of a coincidence, but in general, the 9007 is a superior bulb
because the filament is oriented in-line (like the Audi engine).  This
sends more light to the reflectors and less is wasted on the base of the
bulb or the shield.  OTOH the 9004 bulbs have transverse filaments that
send less light to the reflectors and more is wasted on the base of the
bulb and black shields.  It may or may not give better results on other
headlamps.

>     What can I expect, is it brighter or just a better pattern with
> the newly oriented filaments?

Both.  The low beam pattern is better defined and more uniform with
somewhat better illumination towards the sides, and better cutoff above
horizontal.  Plus with 10w more power on low, it is brighter.  High
beams still leave something to be desired.  The lows could be considered
almost "acceptable" with the 9007 bulbs.

-Luis Marques
 '87 4kcsq