Grill Block 2.25% Increase @ 50 mph.
 

After the air dam failing to gain mileage, I decided to go another route while I ponder the air dam some more.

I went to Home Depot, bought some 7$ flashing and then made a cardboard template. Using the license plate bracket and some leftover aluminum angle, I fabbed up some quick mounting brackets. I also put some angle inside the bottom grill opening to hold the bottom of the flashing in. Once the cardboard template fit, I traced it onto the flashing. I then used some self tapping screws to hold the flashing to the brackets.

Here is the pic I took.
http://i251.photobucket.com/albums/g...ps0d06eded.jpg

Coolant temp stayed right at 195-200*, which is normal. I'll be sure to watch it as the weather gets warmer.

After ABA testing tonight at 50 mph, I got an increase of 1.7% one way and 2.8% increase the other way. Average gain was 2.2%. That is about 1 mpg at 40 mpg. Hopefully the net gain will be higher the faster the car goes. I am out of time to test until next weekend though.

It will take a few miles (4,000) to pay off, but I'll take the gain! I am going to paint it black when I get a minute so it doesn't stick out as much.

Nice work. Congrats with the good result.

Dont forget half the upper grill too. Air dams work best with use of grill block. You want to prevent as much air as possible from going through or under the engine bay. If you jsut do an air dam, then most is sucked through the grill do to the vacuum effect it creates. :eek:

I ran out of time for the upper grill. It is on the to-do list.

So, what your saying is I need to throw my air dam back on and go test again?? The dam is already made. It takes 5 minutes and 8 screws to put back on.

Looks a lot like mine . . . .well, you used the same material anyway!
For the 7 dollar roll of flashing, you should also be able to do the fender skirts.

Oh yeah, 10' of flashing will go a long way...

Looks good! Definitely put an upper grill block on when you get a chance. I found that in the summer, I needed a cooling slot maybe 12"x2" is all; I situated it about where the bottom of the license plate is.

If you paint it, your payoff will 4,050 miles! :p

Nice work, hopefully after a tank or two of highway speeds, you'll see a better gain. I wouldn't do the upper until you know what temps. do to engine temp with the current block. Either that or make it super easy to remove (like pull over and be able to unclip it easy).

What made you go with metal flashing material rather than coroplast?

It is cheap and easy to work with. I cut it with EMT shears.

Thanks for posting the testing results. 2% seems small, but I'll take it.

2.25%
 

If you were seeing 2.25 at 55 mph,then you'd be looking at about a 4.5% drag reduction to explain it.Since it's doing it at 50-mph,then the reduction is even greater,so,shooting from the hip,and considering a generic 12% drag cooling system, it looks like you've cut the cooling drag maybe by half.:)

I'd do a full upper then cut into the lower as needed for cooling purposes.

I notice the biggest improvement in my honda was from 50-70 mph acceleration for merging into traffic. Acceleration was much quicker and it didnt hurt my mpg as much. Of course if your temp starts to go a little high you can always turn on the heater. I also added a bottle of water wetter and used a turkey baster to put the fluid from the rad into the over flow bottle to make room for the additive. :thumbup:

Full upper is on the list. I don't think it will take long to do. In fact, the ABA testing took longer to do on the lower block than did installing it!

I have the timing belt coming up in the next few months. I am going to change the coolant at the same time, so I will be sure to add some water wetter. Good idea.

So, I should be able to cut coolant drag even more by blocking the upper grill too??

I believe so.

I block all but a 2x2 inch square in the summer. I also run the ac which in turn runs the fan on low, so it hovers around 186 degrees all summer long.

When its below 85 degrees out I run a full block year round. Best I can say is get s sg2 or some odb2 reader to watch your water temp and test it.

When this frozen stuff is over Im going to remake a lower air dam out of edging or gutter down spout like I had last year. :eek:

even more
 

Hucho says we can get the 12% down to only 2% although it requires elaborate inlet and outlet ducting,the latter being a challenge for production cars which aren't configured for the space necessary for the ducting.
Here is a link to a low drag cooling system by Walter Korff of Lockheed,designer of the 409-mph 'Goldenrod' streamliner.
Fuel Economy, Hypermiling, EcoModding News and Forum - EcoModder.com - aerohead's Album: Book illustrations - Picture

Aero mods produce the functional equivalent of a horsepower boost at higher speeds. It won't do much for your 0 to 60 mph time, but has a huge effect on your 60 to 100 mph time.

If the cops ever find that out I wont be able to do my mods.

I think the only thing that I could do legally is a curtain air dam, with a smooth "mouth" to drag air in from the bottom of the radiator and then push it out the back, diverting it away from the engine, but my exhaust mainfold is in the way.

I suppose I could remove the last remaining radiator fan and make up an aluminium cowling around the radiator to keep air pressure high until it reaches the bottom of the car, preventing it from running into the engine while its inside of the engine bay.

http://i.imgur.com/8Ys6sZg.jpg
http://ecomodder.com/forum/member-ae...ng-system.html

Definatley going to be a lot of head scratching after I attempt that one, especially about the front mouth of the front grille and intake to the radiator, possibly using some flexible plastic again.

Then, add a thin aftermarket radiator fan to the front air conditioner condenser, so I will have a way of keeping temps under control. There wouldn't be any space at the rear of the radiator as the aluminium cowling will take up the whole space available between the radiator and the engine manifold.

But that "This length equal to radiator height" will put me off severely, I would probably have to increase the front length of my bumper by at least 1/3rd of a foot in order to meet that requirement.

Is there any other options that I may be missing?

You need to keep a radiator fan. If no fan, the engine WILL over heat if you get stopped in traffic.

Keep a radiator fan?? Never planned on taking out the radiator fans.

Today was 70* and the fan came on at long lights (The car was running...) but the coolant temp stayed under 208*.

yoyoyoda is who just mentioned removing the last fan, didn't wanna quote his whole post.

Got it. I was a little confused.

I think its more efficient to use 2 fans at low speed, than 1 at high speed. I doubt the weight of the fan has an effect on mpg and it comes in handy for traffic and AC use. :thumbup:

Is too hot about the same for most cars? The Scangauge shows max temperature @186 on my car. Just added an upper grill block today, but not sure what temp to look out for before removing the block?

Thanks!!

Most Honda's I have dealt with, coolant fan comes on at 205, off at 200. Mind you this was before using a scan gauge, using an Autometer water temp gauge.

FYI: On Honda's up till 2000, the dash gauge does NOT move when the water temps is between 160F and 205F. You could be below the 170F needed to make ECU happy when using the heater in cooler months.

Years ago I wanted to use an RC servo (Futaba S148 or bigger) to control louvers for the grill opening for MPG while cruising as well as airflow below a certain speed, say 30 mph.

That same idea is now used on production cars like the Ford Focus.

That is exactly what I wanted to do, I just didn't know what kind of servos I should use, now I know that I should use RC car servos.

Ty. :thumbup:

Well there are two trains of thought on this, there is that one and there is the train of thought that you can put a 16 inch fan on the radiator and get more airflow through the vanes because a 16 inch fan pushes far more air than 2x 12 inch fans ever could.

I'm still wondering about it all actually. The latest idea is to simply pull the air directly from the ground underneath the front bumper with two large fans, and with the use of an enclosed cowling around the radiator it then dumps the hot air into the sealed engine bay, which then vents at two spots on the bonnet near to the windscreen wipers with a slight positive pressure, the area of the windscreen which is responsible for seeing through is sealed with a factory rubber seal already in place, only the left and right edges of the bonnet are open to outside air.

The entire engine bay is sealed off, to provide an area where positive air pressure can be maintained, except for where it is better to vent the air aerodynamically.

Then the idea is to remove the thermostat, reason being is that we need to keep temps low and keeping the thermostat open all times will keep temps lower until such times as it is required to run the fans to keep things under control. The fans are the thermostat now, and the radiator operates at the exact same temperature as the engine at all times.

This way I can do a full front grille block and a belly pan, the radiator then is using both convection assistance and fan forced cooling assistance. The radiators aren't in the path of the airstream and I can close off the entire engine bay except for the top.

The only problem is I'm concerned about the temperatures achieved inside of the engine bay exceeding the limitations of the wiring inside of the engine bay, and various other issues, for example the transmission overheating, alternator overheating, and the manifold, that can be fixed with manifold thermal tape but I'm still concerned about the temperature then heatsinking back into the head of the engine and cooking the oil ontop of the head from excessive exhaust temperatures.

So I'm waiting on some arduino temp sensors to arrive, which I can then attach to various points inside of the engine bay and obtain current data on temperatures, then compare with the mods.

If I ever need additional hot air exhausting I can then create a tight spot for the air at the very rear of the engine bay along the firewall and then create a mouth which drops down to a limit and opens up to force additional cold air in from the front, the gradient of this opening then can be varied depending upon how much cooling is necessary via arduino programming. Effectivley creating a fully automatic temperature control system. We don't get snow here so its worthwhile looking into if I want to make a smooth aerodynamic underbelly.

Thoughts?

Don't remove the coolant thermostat. Coolant could be circulating all the time and engine would take forever to reach operating temp, esp in cooler temps.

Also the coolant would be circulating much faster than normal and not allow proper heat transfer from the engine to the coolant, the restriction of the fully open thermostat is needed for this.

Please re-read my post.

The idea is to remove the thermostat and block off the airflow to the radiator until such times as you need to vent that heat.

So I simply set the arduino to open up a vent at a specific temperature, until that temperature is reached the radiator remains blocked off, once the temp is reached the gap opens up.

In effect replacing the water thermostat with an air thermostat using vanes controlled by solenoids.

This would actually create a very quick rise in temperature as there is no airflow being forced through the radiator when the vanes are closed. So you can, with this system, drive off and very quickly get a warm engine, then once its reached operating temp the air inlet vane opens up a bit to keep things under control.

Then when things get out of control at lights, the vanes open up completely and the fans kick in, as expected.

The only problem with this is that there needs to be clearance with the road, or at least rollers on the vane at 4 points so it doesn't get damaged going up slight inclines or into driveways.

I went out into the garage on Saturday. I took the bumper apart and went to make the upper grill block. Because of the way I am going to mount the upper, I will need to stiffen the flashing or go with a different material. I didn't get anything done and put the bumper back on since I ran out of time. I didn't want to half-a** something.

The bottom mount is a little floppy; I will need to add another mount. I still need to paint it. I am on spring break this week (still working...) so maybe I will get a minute one night this week to wrench.

It would still take longer to warm up if you remove the coolant thermostat because you have to warm up a larger volume of circulating coolant rather than a small volume of non-circulating.

(PS: please be careful about threadjacking! If you have a great idea for a mod, start a new thread.)

I know what you mean. I find when planning mods, I spend the majority of my time standing there just looking & thinking.

I would say 205-210* is not too hot. I know some people on here go higher than that.

You can always add some water wetter to help cool it with the grill block installed. You can also cut a hole in the grill block if it starts getting too hot.

It went something like this: Try to make cardboard template with bumper on car. Removed bumper and then grill to make template. Stab finger with screw driver, bleed a little. Make template. Hear daughters fighting inside and crying since the older one wanted to make blush out of blue food coloring. Younger one put it on her cheeks and lips and then it wouldn't come off. She started crying. I hastily put the bumper back on then went inside to seperate the girls. Finally put band aid on.

http://img1.wikia.nocookie.net/__cb2...yingSmurfs.png

This does not sound like a case of "You had to be there!"

The newer cars use a 2 stage thermostat that circulates the coolant around the head, then block before it goes into the radiator. Most newer cooling systems are designed for the tstat and it aids in flow. You can usually get a cooler one or drill some holes in it to make it weaker so to speak.