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Lotus Elise HID Upgrade
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Please Note: The information in this guide is provided in the hope that it might be useful in researching your own lighting. Absolutely no assurance or guarantee is made that anything here is correct, factual, or moral. Any loss, damage, or legal violation -- even if explicitly instructed -- is your own fault and not the responsibility of the author.
This page exists to document my own installation of HID lighting in my
2005 Lotus Elise. It was the
first HID installation I have done, and I hope that by sharing these
notes others will have an easier time planning a similar project.
Comments/Corrections
If you have a question you would like to
see answered here, please, send it
along. If you have the answer, all the better!
If you would like to write a long email detailing how very very bad
it is to use HID lighting in a car that didn't come with it from the
factory, you're free to do so. Understand that the reply might be
decidedly shorter.
Click the pictures!
Small thumbnails are provided, but knowing how useful details can
sometimes be, each picture is linked to larger and huger versions as
well.
Picture Copyright
All photos on this page (and the
enlargements linked within) are Copyright (C)2005 Steve Haehnichen and
can not be used for any purpose without permission. You might find
permission is pretty easy to get, but you do have to ask.
Thanks!
Special thanks to the folks on EliseTalk for their detailed help and excellent ideas.
The Lotus Elise uses 55W "H1" bulbs for the low beams (aka "Dipped Beam"). Sensibly enough, this means the headlight fixtures provide an "H1 Mount" to socket the bulb. There is no such thing as a "factory" HID bulb in this H1 mount. Philips and Osram make bulbs for the "P32-d" base, which is a much more sensible design as bases go. The larger bulb opening makes it easier to position and secure bulbs. A factory HID option would likely use those as-is.
But for our H1 mount, several vendors will take the Philips/Osram D2S bulbs and "rebase" them to fit the H1 mount. It's important to find a good quality product here because workmanship varies.
After some research, I decided I wanted 4300K bulbs, Philips one-piece
ballasts, and quality (molded) H1 mounts. I went with this
kit at XenonDepot.com.
XenonDepot.com
I received my kit via DHL from Ontario Canada
in lightning speed. Even with the holidays, it only took a day to
arrive. The kit was nicely packed in a box with a cut-out foam shape
to support the parts, and each capsule was wrapped in bubble tape.
The included harness, though I didn't use it, included generous
amounts of wire, a socketed automotive relay, and 20A fuse in holder.
Email to XenonDepot is answered quickly, and they seem to know their stuff. I'd recommend them.
The XenonDepot kit included a very nicely made wire harness that provides power directly from the 12v battery main and uses the existing H1 bulb socket to switch the relay. This allows the kit to draw power from the battery mains instead of the existing headlight power circuit.
Unfortunately, in the Elise, the battery is far in the back of the car, while the headlights are (quite sensibly) in the front. I could find no easily-accessible source of high-current power in the front crash structure. Arno on EliseTalk explained that there is a 50A power lead available somewhere under the dash, but running wires to it would be quite a bit of work, requiring removal of the dash top and likely drilling.
For this reason, I wanted to find out if a separate power source
(with relay) is not actually necessary, meaning I could power the HID
ballasts directly from the headlight circuits. This is a
controversial approach, and I encourage you to do your own research
before doing the same.
Power Demands
The HID ballasts are rated "20A Max" each according to the
silk-screen labeling. However, HID lighting in general takes less
power than normal Halogen (incandescent) lighting. Hard numbers are
hard to come by, so measurements were in order.
First, the stock headlight bulbs draw 4.5A each. There is a large inrush current as the filament first heats up, but it's very fast -- too brief to measure. With the engine off, the stock wiring provides 12.0v to the H1 connector under load -- excellent voltage, so I'm not worried about sagging below the 9v minimum required by the ballast.
The HID Ballasts draw a large amount of current when first powered on as they ignite the arc and heat the salts in the capsule. It is this startup current that could blow fuses or cause damage to underrated wiring. I measured the highest startup current when the bulbs were cold (green line on chart), and it quickly drops off as they warm up. The highest peak reading was 17A!
Restarting the HID arc while the bulb is hot takes considerably
higher voltage (up to 23 kV) to ignite, but actually less current.
You can see the red line in the graph showing a lower current peak
after the bulb has been resting one minute off and then restarted.
This is clearly beyond the capacity of the 10A fuse.... or is it? The automotive fuses are "slow-blow", so they can take a bit more than the rated current for a brief amount of time. According to Bussmann's spec for the ATC fuse, we should be able to withstand around 17A for a full second without melting. The current spike is actually shorter than that, and the full time spent above 10A is about two or three seconds. In my sample set of two fuses, they have not blown at startup. Your mileage may vary, especially if you see subzero temperatures or have a different ballast core. I will be carrying a few spare fuses in the car, but I'm comfortable with that for now. I will say that I have heard three first-hand reports of HID installations on the existing power wiring, and none have reported power or fuse problems.
After warmup, the HID light levels off to 3.5A of current, which is a full amp less than each halogen bulb. The way I see it, a 2A alternator load savings almost makes up for the kilogram of extra weight added by the ballasts. Right? Okay.
Bench-test your new kit
It's a good idea to hook up all the parts on a bench, support the HID
bulb in such a way that nothing is touching it (hot hot hot), and
apply power to each ballast and bulb. That way you can resolve any
out-of-box problems before having your car all apart and hardware in
difficult-to-reach places, or now out of warranty.
After testing, let the bulbs cool completely and carefully wrap
them in bubble wrap and secure with tape, being careful never to touch
the bulb itself -- only the mount. The wrapping will keep them from
getting touched or cracked during the handling that follows.
Add supplemental battery power
In the process of messing with the headlights, I spent some time with
the headlights on and the engine off. The stock headlights together
draw about 10A, which can take the edge off a charged battery in a
hurry. If you take your time, and plan to take some pictures, notes,
or lunch, it's not a bad idea to hook a Battery Tender or something
similar to the cigarette lighter port to keep the battery topped off
as you work.
Expose fusebox
Remove passenger-side front access panel (one 3mm bolt) to get to the
fusebox containing the headlight fuses. (If you forgot to disarm your
alarm, you will be abruptly reminded at this time.)
By pulling out the LH and RH fuses, you don't have to worry about
accidentally powering the headlights and causing a short. Not
strictly necessary, of course, since you can just remind yourself not
to turn them on while you're working.
Lift the car
There is one "center" jack point under each door that lifts the entire
right or left side of the car. Once raised, you can set blocks under
the rear tire, and a jack stand or something similar under the
front lift point. Each lift point is described in the manual
and marked with a blue sticker. Don't use any other location to lift,
of course.
Unless you want to spend even more time on your back and knees, it's
probably worth the effort to lift the car off the ground a bit.
Especially if you want to...
Remove front wheel
You don't actually have to do this, since you can just crank the wheel
to each side and work around the tire, but it's always easier to give
yourself some elbow room.
Remove front wheel well liner
This one you actually have to do. Release the liner panel by removing
three screws. The bottom two are cosmetic panel fasteners, so it's a
plastic screw in a plastic shroud. Remove the screw, then pull out
the sleeve altogether. The top screw is metal with a washer. Lots of
dirt back there? Yeah, me too.
When you remove this panel, note how it fits in relative to the plumbing, and how the metal tab at the top end fits around the larger wheel well liner. Be sure to replace the tab side first when you reassemble.
My left side liner was missing one of the lower fasteners. I don't
know if that's normal or just missing.
Maybe remove entire liner?
With the goal of easy access and having a look around, I also removed
the larger wheel liner from the car. Each side is held on by three
cosmetic fasteners and just tucked into the lip around the wheel arch.
It comes free easily.
Note that the relay module (for radiator fan / AC) is mounted to the
passenger-side liner, so you will either have to disconnect the wires,
or release the relay box from the riveted mounting tongue before the
liner will come free. You can reach the module through the top access
port more easily if you also remove the black grill half over the
radiator. The module housing does slide off the mount, but it takes
considerable force.
The driver's side liner has nothing attached and comes out easily.
You may be able to get by without removing either of the large
liners, depending on how you want to mount the ballast, but I didn't
try to work around them. On the right side, perhaps leave the liner
loose, but in place as you work behind it -- to avoid messing with the
alarm.
Remove headlight cover
The three 5mm hex bolts hold down the plastic headlight cover. Note
that two of them have lockwashers while one of them (topmost one) has
a lock ring and a full washer.
Once these bolts are out, the entire headlight cover and molded
shroud can be removed from above. Set this somewhere you won't
accidentally kick tools into it, since it scratches easily.
Disconnect all bulbs
I'm all about soldering. Vampire taps, crimp-on splices, electrical
tape, butt connectors, and "scotch-lok" couplers... you can have 'em.
I like the solid connection and longevity of a good soldered and
sealed wire. With this intent, I think it's easiest to just remove
the existing wiring harness to work on it, so I'm not soldering while
cowering in the wheel well.
Disconnect the H1 low-beam bulb spades, the High beam bulb connector (it's tough, but does wiggle off), and the parking light.
Make a note of which way the high beam connector goes (blue or
black wire on top)
Remove wiring harness
With all three lights disconnected, you can bring the whole wiring
harness out of the headlight bay. Inside the wheel well, disconnect
the side light, and then unplug the big four-wire connector from the
wire harness.
When disconnecting the big connector, note that it's affixed to the oil cooler housing. You can either unlatch it by lifting the small tab, or take the easy way out and just pry it free from the housing. It just snaps into place and is easily returned after.
If you prefer to use snap-on wire taps or wire nuts then you can
probably leave all the wires in place.
Remove H1 Halogen Bulb
With the wires released, removing the bulb is easy. Carefully squeeze
the wire clamp and release it from the low-tech `notch' in the base.
Support the base while you do this, so it doesn't sproing itself into
pieces.
Using a clean towel or cloth, take the bulb out of the housing,
being very careful not to touch it with fingers. Any fan of Real Genius can tell
you just how dangerous dirty high-temperature optics can be.
It's a long bulb, so be careful not to pinch it while extracting,
or perhaps scratch the glass on the mount. Wrap the bulb in something
soft and put it in your box of Elise Parts That Have Been Upgraded.
Plan, position, mark, measure, and measure again
With the wires measured, and the ballast mounted, you will have to
have some way to get the high voltage leads from the ballast to the
HID capsule in the headlight. Our options here are limited.
These high-voltage bulb leads are short! Painfully so, especially with the bulb in the cavity and the ballast outside it. The Elise doesn't have a lot of unused space to begin with, much less at the front corners of the car. Measure, simulate, and test-fit before mounting.
Note the size of the HID wire couplers as well -- in this kit,
they're enormous. Fantastic nice connectors, visibly sturdy and
likely watertight, but I didn't want to end up with a solution that
has the connectors pinched between panels.
Consider the HID bulb wire path
Someone more clever than I might be able to thread them through the
existing rubber grommet that houses the wire loom.
I ran into two problems with that approach -- the grommet is positioned pretty far up the headlight cavity, which requires a few more inches of reach that I didn't have. Other HID kits may have longer leads and make this simple.
Second, the HID leads are very high voltage (23kv), specifically so
that they can "arc" and ignite the bulb. The same high voltage makes
me nervous about cramming the wires into a bundle alongside other
wires, or even close to each other. You'd be asking a lot of the wire
insulation.
Position and mount ballast
The ballast is not small, and I don't know if it's water tight, so I
wanted it out of way of road spray. I haven't had good luck with
adhesive tape and heavy things over the long haul (including adhesive
Velcro) so rather than have it fall later, I found a place where I
could sink three screws for a solid mount. Fortunately, there is such
a space on each side, right up against the composite panel around the
front air duct!
On the passenger side, I used three layers of the provided
double-stick tape to make a 'standoff' pad and rest the ballast
against the ridge on the composite panel as shown. With a washer
behind one top screw, I was able to sink three good screws into the
material and firmly mount the ballast. An existing wire loom passes
right above it, but doesn't interfere.
The driver's side is easier, and there are vast tracts of flat fiberglass toward the front of the wheel well and behind the main liner. Both of these locations are close enough to the headlight cavity, but just barely.
The colorful smear you see on each screw is a dab of fingernail
polish ("Concord Grape", I'm told) that might help keep them from
vibrating loose over time.
Drill a hole in your precious Elise
Try as I might, I could not use any of the existing holes to connect
the HID bulb wires, so I drilled a new one. The provided grommet on
the HID bulb is very nice, but rather large.
Check hole for grommet fit
The instructions called for a "23mm" hole, but even my Costco drill
bit set is not that complete. A 5/8" wood bit made a hole almost big
enough, and then a little deburring with a Dremmel tool sanding drum
brought it up to just the right size. I suspect the 3/4" bit would
have been too large for a tight grommet seal.
Even with its generous diameter, this hole is not quite large enough
to fit either one of the HID connectors through. (A better kit might
use more slim connectors.) It was easy enough to remove the connector
shells and thread just the wire tips through the holes. That also
provided a welcomed opportunity to wet a little solder on the spade
lugs, though I doubt it was needed.
Clean up the mess you just made
Carefully blow out any plastic shavings and dust, then wipe the
projector lens with a microfiber cloth. Check the both reflectors for
stray bits. Cleanliness is next to brightness, right?
Don Latex Gloves
While handling the HID bulb, it's important not to get finger oils,
grime, or anything at all on the glass envelope. The arc in the
capsule gets very hot indeed, and any contamination on the surface of
the bulb could cause it to heat unevenly and fail prematurely.
A throw-away pair of proctologist gloves makes it easy to keep your
sweaty fingers safely away from the bulb.
Insert HID bulb
The HID capsule, with return wire, H1 mount and leads attached, is a
seriously long bulb! If it were just a little bit longer it
wouldn't fit in the mount at all. Be very slow and careful about
inserting the new bulb, since it's a bit of a puzzle to maneuver it
into position without cracking the frail ceramic return wire sheath or
the bulb itself.
Think of the bulb as a very expensive glass firecracker with
pea-sized ball of high pressure gas. Next to it is a hair-thin wire
in a long tube of brittle ceramic. If either one cracks, you're out a
couple bills. No need to hurry getting it into position. Make sure
the rotation is correct, with the two 'bumps' on the base aligned with
the two holes in the mount. In my case, the return wire faces the top
the car. (More on this later)
Once fully in the mount, hold it in place and hook the pinch clamp
back into place. The bulb base is thicker than the former
halogen bulb, so you might have to wrestle or bend the clamp to get it
to lock securely. I had a hard time getting the left-side clamp to
stay closed and had to cross the two halves of the clip together. Not ideal, but it seems secure. I was surprised to see such a fragile and skimpy mounting system for the bulb.
Toss gloves
Admire your work and make sure the bulb looks right -- centered and
flush in the mount. Look at it from different angles until you're
convinced it's pointing straight ahead and fully seated and secure.
Route and Seal Wires
Route the bulb wires through the hole, then push and squeeze the
grommet into place. The resulting fit in my car was terrific! It looks
better than the stock wiring, and keeps good wire spacing between the
leads. You want some slack in the wires (no tension on the mount),
but not too much slack since the wire is dearly needed inside.
Connect leads
Once the wires are in the wheel well, you can reattach the bulky
connectors and couple them to the ballast. Plan the positioning so
that they end up tucked next to the headlight cavity, since the
wheel well liner will sit flush against the headlight mold. Some
velcro or Lotus Trunk Tape(tm) can hold them up in place until you get
the liner back in.
Tap power
With the wiring harness removed, it's easy to tap into the existing
headlight power leads. On mine, the solid blue wire was +12v for the
headlamp, with the burly black wire being ground. Double-check with a
continuity tester, of course.
Solder or tap the wires to provide +12v for the ballast. Since the ballast will mount very close to the harness connector, the leads don't need to be long. I cut all but 11 inches off each one, discarding the remainder of the provided wiring in the kit.
It's easy to extract the large 'pins' from the connector itself by
removing the white cover plate, then lifting the release latch on each
pin to extract it. This let me slide some heat-shrink tubing over
each connection, filled with hot-glue for a water-tight and strong
connection.
Restore Lotus Harness
Put the bulb harness back where you found it, and reconnect the side
light, parking light, and high beam. The H1 bulb leads won't be used,
of course, but they're still hot. We need to safely insulate them and
tuck them away, preferably where they won't rattle around, short out,
or melt against the new bulb. I used some tape over the leads, and
then heat-shrink tubing over the whole connector to keep it tight.
Try it out!
With the wiring in place and everything connected, you should be able
to cast First Light. You (and any helpers) might want to stand away
from the light itself in case it suffers an explosive setback.
You put the headlight fuse back in the fusebox first, right? That
makes you smarter than me.
Tune Alignment
Once the light ignites and fills you with joy, you might want to
adjust the alignment and shape of the new beam. Michael Sands has an
excellent tutorial in the Sands Mechanical Museum here
Reassemble
Put back any pieces you removed, being careful to watch for
interference with the new wires. Wheel bolt torque is 77 ft-lbs.
Close cover before striking.
I should mention that some HID pictures were taken with the plastic (clear) headlight cover removed, while the Halogen pictures had the headlight shell in place. I can reshoot most of them once I finish assembly, but the combo (one eye each) picture will stay as it is.
Hopefully the cover shell is not a significant factor in brightness, though it might impact focus and diffusion.
The sight of the HID glow has renewed my faith in the One True
Light.. there is no doubt in my mind that the visibility and safety
has improved immensely over the stock halogen bulbs. I rate this
project a complete success and wouldn't hesitate to recommend it.
I've seen a lot of HID fan pages, and they always include the
required picture showing Just How Bright the HID light is. With
variations in cameras, exposure, and unknown processing the pictures
don't really prove much at all. How can I do better?
With the help of another Elise owner, here is a picture showing
the beams from my HID installation on the left overlapping with the
light from a standard halogen car on the right. The standard lights
have been reaimed to about the same level.
Measurements
The camera I'm using has a sensitive and accurate light meter, and
manual exposure settings. While I wouldn't go counting Lamberts or
photons with it, I think we can make some quantitative statements
about relative brightness.
This picture shows two exposures, one with HID and one stock Halogen bulbs. The backdrop curtain is the same distance from the car, and the camera is in about the same spot at 24mm focal length and ISO200.
I chose these two pictures because each one is right at the limit of overexposure, just starting to get a few pixels "blown out" at the very brightest spot. The two photos are about the same exposure and range, but this is admittedly a subjective judgment.
The important thing is to note the camera settings required to get correct exposure! The HID bulb picture is exposed two full stops less and at a slightly faster shutter speed than the Halogen picture! Mathematically, a photographer might say the HID scene had 4.8 times the light, if you consider the two pictures equivalent in exposure: 4x for the aperture difference, and 1.2x for the shutter speed difference. Would you agree?
It's not a very fair comparison because the HID images are overexposed -- the bright spot in the center is blown out. The Halogen picture is not overexposed and fully captured by the sensor.
Alas, here is the one fly in the ointment. The H1 mount provides a
small 'notch' cutout in the base where the HID capsule conveniently
places the "return wire". This is the wire that extends from the tip
of the bulb back to the base, alongside the bulb itself. It is
insulated by a thin tube of ceramic to prohibit a premature arc of
electricity outside the bulb.
As this wire is not transparent or thin, it casts a shadow on the light projecting from the bulb. In our mount, this wire is on the "top" side of the bulb, creating a pie-wedge shaped shadow of light upward. The projector housing uses a shutter to cut off the bottom half of the light from the reflector, and a single lens to focus it.
Because the lens inverts the light, the shadow ends up blocking light that would be useful. The result is a shadow area in the near-field light pattern from each headlamp. Having driven for a couple weeks with the new lights, I can say that this shadow does not impact the useful reach of the lights. It's greatly exagerated on the "flat wall" photos because the light is not spread out over a large patch of pavement. Once the car is on a flat road, the light pattern is much less distinct, and the wire shadow is largely filled in. Most importantly, the leading edge of the light, the "far" light, is full and bright. It's not a big deal, but still not ideal either.
I don't know what solution is possible for this. Perhaps a
creatively-designed return wire could hook around the base of the
glass capsule and then traverse the bulb on the bottom side to the
tip? Maybe there's some modification to mount the bulb upside-down in
the mount? Any suggestions or product pointers would be welcomed.
The Lotus Double-V
Speaking only for myself, I detest the stock headlight pattern from
these projector housings. It might be all the rage in Europe, but the
"Double V" factory pattern is not where I want light when I'm driving.
The hard cutoff between light and dark is also less than ideal. In
reflector housings, there is a more gradual transition between dark
and light that serves to light distant road markers and provide at
least a little light "out ahead".
The HID upgrade made the light much brighter, and lights a "wider" portion of the road, but the cutoff pattern is set by the shutter and does not change. Just having the brighter HIDs does help fill-in the center area between the lights and extend the reach both left and right. The brighter HID light also allows a bit more flexibility in aiming the lights, as the lower portion is brighter and more useful. All in all, a very worthwhile upgrade.
The rising flare on the right side of each light pattern can be
removed as part of the adjustments, but this further limits the size
of the beam of light, chopping off light (the angled 'tail') rather
than adding back the missing part. The HID bulbs go a long way in
providing more light, but improving the shape of the pattern will
require mechanical changes to the shutter or assembly.
Here are some ideas of what could be found in an improved or Elise-specific HID kit. If you agree, then these are some things to look for in shopping.
Here are some links of interest Lotus Elise and HID hopefuls
Feel free to recommend other reputable vendors for inclusion here.
Copyright ©2005 Steve Haehnichen