Astra Grill Block
 

Hi guys, first post here - your forum has inspired me to start with some winter mods for a little better fuel economy out of my Saturn Astra 1.8L, I average about 28MPG throughout the year, but during winter it gets down more towards 24MPG so I'm looking at building a Grill Block and adding a block heater, and I'm hoping to get some recommendations from the pros on the grill.

I've already created a cardboard template of both the upper and lower grills, and I just picked up a half sheet of Coroplast from a local sign shop, I just need to know what you guys think of blocking the top vs bottom on my car, it looks like most recommend blocking the top, and then possibly some of the bottom on most cars, but because on my car the lower grill is so much bigger than the top, I thought maybe I should go the other way around.

I've posted a picture below, please let me know what you think. Also, what are you guys using as fasteners? I would like to only run it during the winter but have it easily removable and replaceable instead of using zip ties etc, and of course I want it to look clean.

Let me know what you think, thank you!

(oops, cant post images/links yet, please replace the hxxp)

http://lh3.ggpht.com/_71SSBpeEQHc/TQ...308_4653_n.jpg

The top slot of the top grill (above the saturn logo) looks open to under the hood, but it's not, it seals up tight to the hood a few inches in, creating kind of a parachute cavern space...

I'd still block the top... and most of the bottom if not all of it. :)

Is there a piece of plastic between the bumper cover and the main frame member of the front of the car? If that is open, I would block the entire front grill. I did this with my Toyota Matrix and it worked very well in winter.

Not sure, I'll get out there and look tonight.

What were the fasteners that you used on yours? They looked great.

The one with the wood blocks? The blocks are held together with stainless deck screws and I just use a button head stainless screw and fender washer to hold the grill block on.

The previous method just used 10-32 thumb screws and wing nuts. It worked alright but did loosen up in spring.

Here is the new and IMO better way if your grill is recessed. The thumb screw way works good for flush mounting.

http://ecomodder.com/forum/showthrea...hod-15335.html

I meant these: http://ecomodder.com/forum/showthrea...html#post38045

Ah, yeah. That method works good if you want to mount the grill block flush with the grill. If you grill is inset like most lower grills are, the wood block way works great.

Yeah, my lower grill I will use blocks, the upper I was hoping to use a similar plastic (?) fastener like yours, where did you get those and how do they mount up from behind?

I did the same type of block on my Prius. I got a picture of the fasteners I used. They're just thumb screws, fender washers, and wing nuts.

http://ecomodder.com/forum/showthrea...tml#post143460

http://www.tercelreference.com/downloads/prius020.JPG


http://www.tercelreference.com/downloads/prius021.JPG

Oh perfect, simple enough. You rock, thanks for the help!

You can put the grill blocks on the inside.
Stealth ;)
Slightly less efficient than a smooth front, but it'll still work OK.
It's how car manufacturers do it.

I'd block the entire upper grille, and half the lower grille.
If air can get to the radiator behind/below the front spoiler, block the entire lower grille.

Keep an eye on the coolant temperature though !

Yeah, by putting them on the outside, I'm hoping to avoid this, lol

http://sphotos.ak.fbcdn.net/photos-a...55325_6243.jpg

Well, here's what I came up with - not sure if it will be the permanent solution or not but I'll test it out tomorrow and keep an eye on the temps and go from there. The shape of the top grill ended up being a lot more difficult than I thought, so I screwed it up, I'll have to try again on that one but for now it has the foam pipe wrap on it. The two 1.5" holes in the lower block are right in front of some temperature sensors, does it make sense to allow those to breathe like this or should I cover them up?

http://lh4.ggpht.com/_71SSBpeEQHc/TQ...216_234512.jpg

Looks good. You can do either with the holes. I leave mine covered. This does mess with the outside temp sensor a little bit (they react slower), but it doesn't bother me. I'd rather have my car get warm faster and stay warm!

Hit a max temp of 99c on the 20 mile commute this morning, I was getting nervous because the normal max is 90c but after doing the math, that's only a difference of 16f with a max of 210f, I guess I'll have to find out what temp the fan comes on normally.

There was something nerve-wrecking about 99c never hitting 100c, but in Fahrenheit it doesn't look so bad! lol

That is pretty warm. You might want to pull out the foam or put some more holes in the bottom. I'd bet your radiator fan is turning on.

Thanks, yeah I've pulled the foam and I'll keep an eye on it on the way home tonight, from some quick research, it looks like the fan comes on at 99c so that's why I never saw it hit 100c.

aearles -

My fan automatically comes on at 220 degrees F. I have a manual fan radiator switch on my Saturn S-Series, and I usually turn it on at 210 degrees F.

CarloSW2

Well, I removed the foam from the top grill and the trip home was a success, it maintained it's normal old max of about 92 bouncing back to 90, and seemed to warm up faster, of course I did no scientific tests before hand so it's probably just in my head - but I'm okay with that as long as I FEEL warmer!

I'll probably leave it as is and keep an eye on temps, I may switch it around or try to make it more flush but I was more interested in the faster warmup than the FE gains, of course those are always good too so we'll see..

Thanks for the help.