I basjoosed my headlights today (sealed the surrounding gap)
 

basjoos (v.) - to make aerodynamic optimizations at a micro (vs. macro) level.

(OK, yes, obviously basjoos does macro too, but whenever I start nitpicking about some small aero detail, I instantly think about his silicone-filled panel gaps. The "basjoosed panel gaps".)

---

http://ecomodder.com/forum/attachmen...7&d=1197476035

So, no, I don't have any pics to post yet, but today I bought a roll of 3 mm (about 1/8) thick peel 'n' stick weatherstrip because I was looking for a quick 'n' clean aeromod project to do before my next big one.

I fit the foam strip in the gap all around the driver's side headlight assembly. (I'll do the other side tomorrow.)

That gap ultimately leads into the engine compartment and under the car, so despite it being a small area, it's pretty much the top of the list in terms of where I don't want air to go unnecessarily.

I calculated a total open area of 43.2 cm2 around both lights, or 6.7 square inches.

Inconsequential? Mercedes didn't think so ("sealed joints on headlights"):

http://ecomodder.com/forum/attachmen...1&d=1204235894

From thread: http://ecomodder.com/forum/showthrea...5-up-1221.html

Wow... 0.25 Cd. I wonder how much of that is because of the FULL SMOOTH-SURFACED UNDERBODY PANELING? :D Looks like they don't consider the hubcaps a priority, opting for weight over aero.

I never gave that gap much thought but now that you mention it and seeing that pic... you're making me a believer. I recently removed my ad hoc smooth hubcaps and rear skirts because they weren't having any effect on my routes but this sounds easy/small enough for me to squeeze in before I get back to my real job of schooling.

Does Prius have a "show me" diagram like that? I'd be interested in seeing all their upgrades, plus those from the Volt. Time to call upon the mighty search engine gods!

Really? Are you able to detect a change as small as a couple of percent above the noise of normal variation?

I haven't seen one. If you turn anything up, let us know.

There was some slight noise reduction but it didn't translate to my scangauge. I will need more testing though under more optimal conditions. The wind lately has been annoying (HEADWIND???) and another reason I needed to remove all the tire tape was because I was getting my tires rotated today. :D

Got a lot of questions about my grill block though... blue tape does that.

When I was fixing my inner fenders on my TDI (replaced one, coroplast-patched the other), I noticed that I could see HUGE gaps between my headlights and bumpers. I ended up stuffing 1/2" x 7/16" weatherstripping into the gap below.

If I need airflow into the engine bay -- well, that's what the vents for the Radiator and Intercooler are for, not "extra" venting via the headlights.

No idea what improvement it's doing at this point, since I'm still calibrating my Scanguage II. That said, I know sealing that up that gap into a dead space shouldn't be counter productive.

I'd imagine the minor air ducting to the lamps is to dissipate the heat produced by the bulbs.

azrealswrd: Ben suggested I use lime green tape for my temporary mods. Nuh uh. :) I bet your blue tape got lots of attention.

The fact that you thought it was quieter tells me that's probably a worthwhile aeromod.

ChristphrR: well, I did the other light this evening, and measured it. Total gap area (projected) around both headlight assemblies is 43.2 cm2, or 6.7 square inches - practically the size of a business card.

I figure: if I've got a business card sized hole smack in the front of my car that does nothing functional, and ultimately lets air into the aerodynamic torture chamber that is the engine compartment/underbody area, why wouldn't I cover it up?

GM obviously thought it was worth putting speed tape over the headlights (and other panel gaps) to squeeze max efficiency from the GM EV1 / Impact for its record setting speed run:

http://ecomodder.com/forum/member-ae...-duct-tape.jpg

Will post pics of my weatherstripping mod in a few minutes...

I seen that on Christine when doing the front grill block (bumper block) and was surprised at all the air gaps! I was not at all concerned with an entire blockage after seeing all this..............

http://i75.photobucket.com/albums/i3.../grille013.jpg

Pics:

http://ecomodder.com/forum/attachmen...1&d=1219712622

Above: the gaps! It's no Lexus.

http://ecomodder.com/forum/attachmen...1&d=1219712428

The 3 mm weatherstripping. I cut this in half, width wise.

http://ecomodder.com/forum/attachmen...1&d=1219712428

This worked out quite nicely: the strip was just the right size so I could position it in the gap and peel the backing off with it staying in place. Then I lifted up on the bumper to squish the adhesive down nicely.

http://ecomodder.com/forum/attachmen...1&d=1219712428

Top view: the hood presses lightly against this.

http://ecomodder.com/forum/attachmen...1&d=1219712428

No more business card size hole in the front of the car! Mercedes, eat your heart out.

I need to finish the quarter panel gap around the side marker portion of the assembly. I'll just use black silicone there since it's too small for the foam strip.

Hrm, well, maybe I'll clean out the car, and put a fire extinguisher inside. (My Dad and I both have the bad luck of having vehicle fires, anyway...)

And MetroMPG - nice picture showing the before, during, and after.

The size of the gap under your lights looks a lot like what I saw under my car (different make and all). I used a broken DQ Blizzard spoon to help shoehorn my weatherstripping under the lights, sticking it to the bumper fascia on the bottom, and sticking the top weather stripping to the plastic lense, again, like you did.

Nice job. And for very little cost.

My Celebrity has a pretty nicely put together front end, the headlights have virtually no gaps around them and everything is a clean look and is secure. The 6000, on the other hand, same year, has this front end that just looks so slapped together like a beginner high school shop project. Huge gaps, and nothing really lines up very well. Even the attachment of the grille itself is this hokey setup with these rubber clip things that rot, and these plastic clips on the sides that break off about every other time you remove the grille. Would probably be worth it and look better to just make an entire new solid grille for the 6000 out of coroplast.

MetroMPG -

Thanks for the pix. I have some of this tape on the top of my headlights. My gap was so big I had to double-decker it. Now I need to take another look at the other places I can tape.

CarloSW2

I just did mine around the top of my headlights and I continued it up the side of under the hood. There is and even bigger gap that I actually doubled up on the weatherstripping to fill it.

I was thinking I'd probably do the same thing. Looks like you found some better (thicker) weatherstripping than I did.

No I think it's the same stuff, I just had to do two layers for under the hood. Found the 1/2 thick stuff at Wal-Mart for about $2.50 a roll, I think Lowes has it too, but I'm not sure the price difference.

OH, and around the headlights I noticed there is a bracket for the lens, so I made sure to put a separate piece on that and cut out around the screw head just in case I needed to get it out one day. It wasn't as clean as I had wanted but it works for now.

I didn't even think about under the headlights! oh, and I noticed you didn't try to squeeze the weatherstripping in between the little notch and the inside of the lights coming up from the bumper, it was a pain but I got mine in there.

Just FYI, I'm jealous of your black bumper, It's really a pain in the butt trying to figure out how I'm going to cover up that stupid 'Schlick Quattro' bumper on mine without it looks ridiculous! (see pic in my garage)

Weatherstripping on headlamps...
 

Hey, before I try something like this...have any of you done much night driving with the weatherstripping on the headlamps like that? Back when I used to work for the GM dealership I saw some pretty strange things happen to things accidentally against a headlamp. I'd for sure want something with a high melting point - like the rubber strips the OEMs use...

Do some of those weatherstrips say "hi-temp"???

That is an interesting question. Although I don't do too much night driving I would still want to know if anyone has noticed anything. Also, has anyone noticed any difference in fe from doing the weatherstripping? How noticeable is the weatherstripping? I don't want my car to look like it has mods, I want it to look like it's supposed to be there.

You won't be able to detect any fuel consumption difference by doing this mod. It was the equivalent of closing up a business card-sized hole in the front of the car. That's not to say it doesn't help a small amount, only that the effect will be smaller than the normal variation in your fuel consumption from other factors.

FYI, the weather stripping between the bumper and the light on my car has come undone and the foam has slid further back than I'd like. The double-sided adhesive didn't stick to the foam as well as it did to the paint.

I'm guessing this is due to heat - not from the headlights but from sunlight on the black foam/black paint. (If it was heat from the lights, the strip on top of the headlight assembly would have let go too, but it's fine - because it's shielded from direct sun when the hood is closed.)

I've seen the "adhesive didn't stick to the foam" issue with several different weatherstrips when trying to stop water leaks on different cars - after a while the foam seems to draw up, and leaves a sticky mess.

Still, I like the idea. Every little bit helps when looking for ultimate mpg, even if one particular idea doesn't show a measureable gain.

Hey, I just remembered something! Use something like a trunk lid or door weatherstrip. Maybe a piece of door w'strip or lip seal off an old car. Most of those are better with heat, and won't draw up. It'll look more professional, too. Rub silicone on the "face" to keep it from being pulled by whatever contacts it. I can't remember if the yellow or black w'strip adhesive works best, but maybe one of you guys do.:thumbup:

That pretty much describes the situation.

I'm just going to reposition the foam to act as a backstop for black silicone caulk.

great mods, I'll be doing this to the hood and front end of my truck
tomorrow if I can get my oil change and other maintenance done..

Looks like filling in gaps is the definite way forward. I've got an ECO4 which is a factory modified Astra to increase fuel economy. I just had a look at the headlights and they have a rubber surround which looks like used to fill in gaps. I don't know whether it's an ECO4 specific mod, or standard on all Astras, but it's interesting to see this. It has the same rubber at the bottom of the headlights but it's hard to take a good picture of that.

http://74.53.75.74/~biased/gallery2/...serialNumber=2

Nice. And i see they insulated the battery, with an opening to the front to admit cold air. I guess the engine bay can get pretty hot then?

ollie

No idea. Didn't think too hard why they insulated the battery. Can't guess why.

Back on topic, yesterday went to the supermarket, funnily enough while there were about 20 cars there, I parked between 2 identical silver astra's. They were even the same model level - LS (but not LS ECO4 like mine). I checked out their headlights they both had the same rubber strip all the way round. I now doubt they put that in to improve areodynamics, they are probably just there to prevent bonnet rattling on the lights and cracking them?

I wouldn't discount the aero benefit as a reason they've done it. Also possibly to keep down soiling in the engine compartment, and possibly to improve cooling performance (higher pressure differential if you keep high pressure air from "leaking" into the engine compartment past the radiator).

I am working on doing the exact same thing with my wife's Avenger. Dodge did a better job on it than my truck, but it can still use some cleaning up...

That would be my guess. I know VW Rabbits and Jetta 1s were hard on batteries. The battery shop told me they were pretty surprised I got five years out of mine. It sat right behind the radiator, so it got a good heat soak...

I also think door moulding, the type that presses over the pinch weld would work very well (provided the edge of the plastic bumper is close to the opening)
Typically they are nice and soft, compress well, and don't move!

Maybe a trip to the junkyard to take one off a car, pick one that's torn so the guy at the counter will go "Eh take it" then cut/use what ya need.

Oh how I wish the local junk yard wasn't over 100 miles away!

I know the reason for that!

A clean battery will last a lot longer than one exposed to dirt and grime. One of the main causes of battery failure is dirt covering the surface and effetively slowly shorting it to death. A constantly discharged battery will eventually die, but one that is kept clinically clean, and also incidentally, protected from temperature extremes, can last the life of the car.

A friend of mine had a late 90s Pontiac Bonneville where the battery was kept in a storage compartment under the back seat. It was kept clean and insulated, and it was the OEM original battery. He said he's never had any issues with it!

every little bit helps, my car could definitely benefit from this, theres so many holes in the front its not funny!!!

anyone every think of just using silicone to fill in the gaps around the head light?

That's what I'm going to do. Just bought a tube of black silicone today. A little painters tape to keep it where I want it, I'll be all sealed up and it won't even show.

take some pics! would love to see your project!

that black silicone will turn either grey or brown (depending on manufacturer) in a very short time.
Ive done the lower gap on all my vehicles for the past several years. although I did leave the upper gap for ventilation, as mentioned before, the headlamps can get pretty darn hot and I didnt want to tempt fate :)
I tried sealing my headlamps on my old ranger but nothing lasted very long, so I ended up just buying some covers. they did a pretty good job of covering the gaps around most edges, but also covered that gap between the headlamp and turn signal.

the stock image shows how much gap there is around the entire thing, but there is a significant gap also between the components that make up the HL assembly. which you can see a little better in the pic of the covers installed.
not sure how much of an aero effect it had, but Im thinking it had to have some. :)

d0sitmatr is right. The black RTV I buy is grey coming out of the tube! I may have to do something similar to what you did (maybe w/foam tape or corroplast), as there's a 1/2inch gap from my headlights to the bumper cover...

The foam tape didn't last either. By the next season it was also grey & weathered, and some of the adhesive was gone too, and it was out of place.

Silicone or equivalent is probably best.

anyone try window weld?

I did this with black silicone on my black car. Can't tell it's there.

I used black RTV on my last pickup and after 11 years it was still black (once I washed the dirt off of it). The RTV I used on the topper for my present truck is still black after a little more than a year. The stuff I use is what Home Depot typically sells. I think it is made by GE.