Sealing Panel Gaps - Fuel Economy, Hypermiling, EcoModding News and Forum

HydroJim · 10-14-2011, 12:57 PM

I'm looking to seal all the gaps on my car. The main one for now is going to be the gap around the rear quarter panel windows. I know I could use tape, but I'm looking for a professional looking and long lasting solution. I was thinking of using some sort of caulking in the gap, but I'm not sure how well this will hold up against the elements. I'm also worried about the sealant reacting with the paint. Any ideas? I attached a picture so you can get an idea of the gap I'm talking about.

NeilBlanchard · 10-14-2011, 01:47 PM

Those are not the gaps I would worry about. The hood gaps maybe, or add a Kamm back -- the Focus is not great back there. The Cd is 0.36 if I am not mistaken, and the back is too rounded. Smooth wheel covers, rear wheel skirts, belly pan, Kamm back -- these are the low hanging fruit.

HydroJim · 10-14-2011, 03:16 PM

I'm planning on doing all those mods, I just started thinking about how I'll do the little things when the time comes. I have to learn how to drive first before I Start doing anything to this car. Surprisingly, my ZX3 came with the headlights already sealed. I'm not sure if that's a stock or not, but it definitely looks like the car came like that.

So you think I should just ignore the gaps around the windows?

tru · 10-14-2011, 03:42 PM

Quote:

Originally Posted by HydroJim

I'm planning on doing all those mods, I just started thinking about how I'll do the little things when the time comes. I have to learn how to drive first before I Start doing anything to this car. Surprisingly, my ZX3 came with the headlights already sealed. I'm not sure if that's a stock or not, but it definitely looks like the car came like that.

So you think I should just ignore the gaps around the windows?

the headlights do have some type of barrier but the hood-grill is a large gap between the headlights.

Im looking to do the same thing to my focus this weekend with clear silicone... will see how it works out.

HydroJim · 10-14-2011, 06:27 PM

Alright tru, tell me how it works out. Make sure the silicone won't react with the surface that you put it on. What gaps are you going to be sealing?

jkv357 · 10-14-2011, 06:32 PM

I'd be surprised if there were any aero gains from sealing the gaps that far back.

As noted, look at the front gaps, wheels, underbody, mirrors, hatch angle, etc, first.

As far as sealing, there are foam (rope type) seals that you could force in the gaps, or use some kind of strip caulk, if you don't want it to be as permanent as liquid caulk.

Looks nice!

HighMPG · 10-15-2011, 01:44 AM

Remove your mirrors and under body first IMO!

TXwaterdog · 10-15-2011, 12:59 PM

If your worried about a paint reaction, call a body shop or stop by one. They will know for sure. I personally wouldn't think twice about applying a silicon based caulk to it. I apply silicon lube on just about everything under the hood from intake hose to plug wires.

HydroJim · 10-15-2011, 03:37 PM

Everyone seems so worried about all the other causes of drag. Don't worry, I'm just in the planning stages.

I don't even have my temps yet so the car isn't even being driven. Right now I'm just planning all my mods so I can budget my money when the time comes. I'll be modding it basjoos style and doing it all at once so I figured I'll take care of every little thing possible. Including the smallest of gaps!

I'm starting to think about using tape again because it's so easy. Anybody know of any clear tape that won't rip off the paint if it needs to be removed, and last for a good amount of time?

tru · 10-16-2011, 11:16 PM

i silicone caulked the under headlights and around the front grill. my car is newer than yours and has a chrome surround on the upper grill. i blocked off the upper grill and now siliconed the gaps between the chrome trim piece and the "sheet metal" of the car. i was surprised at how easy it was to apply and it looks pretty good in person.