Grill blocking in hotter climates

[HilseeJ]

http://upload.wikimedia.org/wikipedi...-Fit-Sport.jpg

In the above link is a picture of my car, the honda fit, 2007 model.

I have basically run out of things that I can do to it within reason. The car is naturally attractive, so ugly tire covers are not an option. Wheel well covers are also ugly, and not an option. I am working on a kill-switch, and I have a scangauge.

That leaves a grill block. It would be barely noticable, due to the fact that my car is white.

I was thinking about blocking out the whole bottom section, leaving the hood gap as it is.

Anyone seeing any future possible problems? I have a scangauge. Will the temperature gauge on it be good enough?

(I'm in southern Alabama, close to the coast. It's hot, humid, and rainy.)

[Tesla]

Most cases temp should be fine with just one opening, but you will need to monitor temps in the first hot spell to get a feel for how coolant temp is in warmer weather.

2 points:
1 / A more favourable result is usually achieved by blocking upper grill and drawing cooling air from the lower grille.
2 / Where does the air go after it passes through the grill, most cars have gaping holes all around the radiator, best results will be achieved if all other holes are sealed and the radiator is the only exit for air passing through the grille.

[Piwoslaw]

Blocking the upper grille has a better effect on aero than the lower grille, so start with it. Many cars can easily do without their upper grilles.

As for the lower grille, start blocking it from the sides and work your way in. The point where you can keep it blocked year round is what you make permanent, and for the colder months you can temporarily block even more.

You can also make an openable grille block so that you get both shorter warmup and cooling when needed. I did it with power lock motors, so I only need to press a button:

Originally Posted by HilseeJ

I have a scangauge. Will the temperature gauge on it be good enough?

My SG shows the coolant temperature much more accurately than the dashboard's temp gauge.

[HilseeJ]

Originally Posted by Tesla

2 / Where does the air go after it passes through the grill, most cars have gaping holes all around the radiator, best results will be achieved if all other holes are sealed and the radiator is the only exit for air passing through the grille.

If you're talking about the gaps where the radiator stops but the gaps are still there on each side of the grill, then yes, I have that. Are you suggesting blocking the sides?

Other questions (directed towards everyone):

How will I know what the optimal temperature is? Do I want to keep it at the same temperature as what it would be without the grill blocks?

@ Piwoslaw:

How much did that whole automatic setup cost? Even if it's only $20, that seems kinda high considering that's basically a tank of gas.

[Piwoslaw]

Originally Posted by HilseeJ

If you're talking about the gaps where the radiator stops but the gaps are still there on each side of the grill, then yes, I have that. Are you suggesting blocking the sides?

Yes, and the top and bottom also. Basically you want a duct from the grille to the radiator, so if any air comes in through the grille, it won't go around the rad.

Originally Posted by HilseeJ

How will I know what the optimal temperature is? Do I want to keep it at the same temperature as what it would be without the grill blocks?

Normally a slightly higher temperature is good for fuel efficiency. A few ecomodders have switched their 185°F thermostat for a 195°F model. You probably shouldn't go above 205°F too often.

Originally Posted by HilseeJ

@ Piwoslaw:

How much did that whole automatic setup cost? Even if it's only $20, that seems kinda high considering that's basically a tank of gas.

That depends on how much you pay for fuel. Here a gallon costs about $6. The two motors (one of the radiator, one for the intercooler) cost maybe $12, plus switches would bring it to $20. Plastic, screws, wires and other random stuff was free.
In my case the grille block is a must: My turbodiesel is already quite efficient, so with efficient driving it is wasting very little energy in the form of heat. In sub-freezing temperatures I have trouble keeping at operating temperature (>80°C/176°F), even with grille blocks and engine insulation. So in my case it's about keeping the engine at a healthy temperature.

[Tesla]

Originally Posted by Piwoslaw

Yes, and the top and bottom also. Basically you want a duct from the grille to the radiator, so if any air comes in through the grille, it won't go around the rad.

Yes, exactly that,
I don't think this point is highlighted often enough with the grille block mod.
If you reduce inlet hole (grill area), but you have gaping holes behind the grille that allow air to bypass the radiator, then the most likely outcome is that you will not see any gains and will probably have overheating issues.
The aim as said is to create a duct with one inlet, the reduced grille area and one outlet, the radiator outlet, so that all air passing through is used for cooling, and it is surprising how little air is actually required when this is done well.

[JRMichler]

My grille is fully blocked, except for a small opening under the license plate. You can't see that opening in the photos. The air going into it is moving straight up.

I only saw the temperature rise once. It was a 93 degree day, AC going, and a long upgrade. The rise was only 5 or 7 degrees F, not enough to turn on the engine cooling fan.

The best place for getting air to the radiator is low and center - that's where the highest pressure is found. All vehicles are different, so you will need to find out for yourself what works. The above advice about making sure that all air goes through, not around, the radiator is 100% correct.

[sid]

I live in the Tampa Bay area of Florida. I blocked the upper grill on my Ford Ranger about two years ago. My average engine temperature has actually dropped about 6 degrees since adding the grill block. The temperature readings are from my Scangauge.

So try it. If your engine temperature seems higher than normal, you can always remove it.

[Miller88]

For what it's worth, I blocked 2 of the 3 lower grilles on my Focus and it ran COOLER. Without them, on a hot day, with the A/C on, it would run between 87 and 89C, with them, it was 85-87C.

Now, with it fully blocked off, I did manage to get the car q bit on the toasty side on a 4F day. Gotta be careful. Mine is a manual, so no A/T to make heat. I'm going to experiement with blocking about 2.5/3 of the grilles off to see if that helps

[cRiPpLe_rOoStEr]

Originally Posted by Piwoslaw

You can also make an openable grille block so that you get both shorter warmup and cooling when needed. I did it with power lock motors, so I only need to press a button:

I'm still quite skeptic about grille blocks, but if I'd ever try it I'd get an openable one.