Grill Block 2.25% Increase @ 50 mph.

[MetroMPG]

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

[aerohead]

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.

[mikeyjd]

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

[Cobb]

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.

[sarguy01]

Originally Posted by mikeyjd

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

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!

[sarguy01]

Originally Posted by Cobb

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.

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.

[sarguy01]

Originally Posted by aerohead

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.

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

[mikeyjd]

Originally Posted by sarguy01

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

I believe so.

[Cobb]

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.

[aerohead]

Originally Posted by sarguy01

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

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