Modifying the Front Bumper

The standard Colt/Summit/Lancer bumper can of course be replaced by a variety of body kits. My aim was to keep the car looking as ex-factory standard as possible, in part to not attract unwanted attention. I also wanted to add some decent quality driving lights into the bumper area.

Earlier project modifications to the bumper added two 80mm air flow holes for the oil cooler mounted behind the bumper reinforcement bar, opened the RHS blanked out fog light region and added an 100mm air intake for the side mounted intercooler, as shown below outlined in yellow. The three circular holes are walled with sections of plumbing grade black 80 or 100mm ABS tube.

The new driving lights when mounted in the bumper would look something like this.

So ... the flexible polyurethane bumper has to be modified and suitable brackets for the driving lights fabricated.

 

Choosing the Driving Lights.

When purchasing lights (fog or driving), you absolutely get what you pay for. Cheap (usually Chinese made) lights in the $40-80 range are a complete waste of money. The optically inferior lens and reflectors tend to produce unfocused glare and the materials and metal parts badly made and poorly plated.

I looked at four brands, Blazer Tech, Westin, Hella and PIAA, to evaluate the manufacturing quality, beam focus and stray light (random unfocused light from the cheap lens and reflector that causes glare and retroreflection in fog, rain or snow).

To test stray light, connect your lamp to a battery in a darkened garage, and point it at the back wall. Stray light will illuminate the ceiling.

Blazer lights (approx $80 for the set of 2) are low end and can be categorized as acceptable but have significant stray light.

Westin (about $100 for the set of 2, made in Taiwan for a Texas company) claim superior stray light performance on the box, and this is correct. I rate them as adequate, but not as good as I'd like because the beam gets rather unfocused at distance.

Hella (about $120 for the set of 2) I rate as superior, with a distance focused beam. These are the lights I chose.

PIAA are simply outstanding but the $200 per pair price deters many buyers.

Making the Bumper Cut Outs

To inset 160mm round lights into the bumper, holes have to be cut and walled. You can get plumbing grade 6" ABS tube unions that have an 6-8mm wall, a 170mm ID and are about 200mm long for about $30. One of these unions is enough to make both the driving light inserts.

The position of the lamps is affected by the body work behind the bumper, so the cutout sections remove the existing fog light locations.

Lamp position is also affected by local regulation. Fog lights (i.e. a wide angle, 60 degree plus, short range beam) are mounted low so as to illuminate the road under the fog level. Driving lights (long range typical beam width is 25-35 degrees) are better mounted as high as is feasible. Since the intent here is to mount the lights in the bumper, the lamp center will be a few cm higher than a fog light.

The lamp tubes have to fit parallel to the bumper reinforcement box section, which requires removal of a small section of the box section seam. If you want to mount the lamps a bit higher, say another 30mm, you'll have to cut out a piece of the box section and plate it back in with 12G or 10G steel.

The cover polyurethane is easily cut with a hacksaw or snips, and ground to the final contour with a rotary sanding wheel.

Glueing and filling the new lamp tubes.

You'll need a two part flexible bumper repair epoxy adhesive/filler that cost about $30 for the larger kit. Check with your local body shop supplier for suitable products.

  Front view of the installed lamp tube

 

  The rear view of the lamp tube. Note how close the tube is to the box section, and the cut out (lower left) for the oil cooler.

The box section seam under the tube was ground away so the tube sits parallel to the box section.

  Modifying the Hella lights

The lamp (lens/reflector) assembly is held in the ABS body with a clip and screw system that extends below the l60mm lens circumferance, and hence it does not fit in the 170mm ID of the ABS tube. Also, the lamp mounting point is inconveniently positioned and would require cutting out a section of the bottom edge of the bumper cover.

It's therefore necessary to modify the lamp body to

These modifications will allow the lamp to fit snuggly in the ABS tube, and also be easy to adjust the aiming when the bumper is fitted to the car.

 

 

This is done by fabricating a section of 1/2" polycarbonate sheet that's glued inside the lamp shell using the bumper repair epoxy. This piece takes a thread for the new clip system and the lower M6 bolt for the new mounts.

 

 

 

The new mounts have two M6 bolts and nuts and one M6 bolt that secures the mount to the lamp body.

 

 

Here's the rear bracket fitted, and showing the new low profile lens clip. The screw taps into the polycarbonate insert glued inside the lamp body.

Fabricating the lamp brackets

Even with the new lamp mounting points, the lamps will still need to be solidly mounted so they don't vibrate when the car is driven. This is not only extremely irritating for the driver but also stresses the mounting points and can lead to fatigue failures.

The main mounts are at the bottom, and the vibration mount is at the top.

Lamp Covers

The original Hella lamp covers won't fit in the lamp tubes because of the lamp clip system, so digging around in my garage I found some old 1G Talon center caps with the Eagle logo. A little bit of paint and detailing in white, and we have attractive driving light covers.

When fitted to the car with some adapter hardware fabricated with polycarbonate strip it looks like this.

Driving Light Switches and Electrical Mods

Driving lights require a dedicated fuse and relay system.

The triple 20/30A fuse box comes from a 2G Talon and is adapted to fit into the GTX. The battery +ive lead connects to an insulated bolt, and the starter cable (outlined in yellow) runs off the lower end of the bolt. The large busbar on the top left is a set of ground points for various circuits.

There are two relays, one for the new driving, and another (hidden behind) for optional fog or other driving lights.

In the cabin, the LHS vent panel has two dummy push button switches not used in North American models. In Japanese models these switches are used for fog lights and I think a rear window wiper. With some reworking of the button covers, these can be retrofitted with switches from the center console.

Here's the schematic. Note here that the headlights and driving light relays are energized by grounding the relay coil, not by applying +12v to the a grounded relay coil.

Diode D1 (a 1A diode is enough) is required so that the driving lights won't turn on when the dimmer switch is in Lo position. Relays don't need much current (about 250mA) to energize, and the D1 prevents the Driving light relay energizing via the quad beam relay, the high beam filament and down to ground.

 

Making LED based side marker lights

The blanked marker light filler panel with the Chrysler pentastar simply snaps into place and can be removed with a screwdriver. This plastic filler panel can be reworked to create LED based side marker and flasher repeater lights. You need the following for each panel:

The completed marker lamp looks like this. The LEDs once connected in circuit are covered by epoxy which also glues the lamp base in place.

The unmodified filler panel, the fabricated polycarbonate base holder, recycled lamp base and connector before reworking and assembly.

Circuit Description

Each LED has a Vf (forward voltage) of about 4 volts. Note that Vf varies from device manufacturer, and also slightly with current. The maximum brightness of approx 6000 mcd is achieved at a typical maximum current of 25mA. Hence the three LEDS have a combined Vf of 12v, so the 1/4W current limiting resistor R1 has to drop about 1.3v.

The indicator circuit applies +12v at the first resistor, and drives the LEDs (L1-3) at 25mA. The Taillight circuit applies +12v via an additional resistor and diode such that marker current to the LEDs is limited to 10mA ie brightness is 40% or the maximum. The diode D1 prevents indicator current driving the taillight circuit.

Functionally, the LEDs are always on for marker brightness, and switch to maximum brightness for indicators.

Caveat

LEDs are more directional a bulb and reflector.

Disclaimer

This information is provided for interest only. No warranty is provided or offered. Use it at your own risk.


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