Grill Block 2.25% Increase @ 50 mph.

[fusion210]

I really like my plexiglass ones made from some scrap material. They're stealthy.






Mine were worth around 5% for my low speed commute. I thank the faster warm up times, it's hard to have an efficient engine in the winter that doesn't get up to temp. Thanks to all the coasting, it wouldn't even reach 170* in mild NC winters.


I cut them to match the openings, drilled some holes and used zip ties to attach them.

[sarguy01]

Originally Posted by ssnsvibe09

I had two upper grill blocks install and the lower one on for a few days but the temperature was hitting 200. so I took off the lower one, to lower the temperature down to around 185, but your recent posts had me thinking to swap things around.

This morning I reinstalled the lower one and removed the right hand side.

Is 200* too high for your tastes??

If I ever get the time to make the upper grill block, I will have to play around with opening sizes to ensure the temps stay reasonable.

[sarguy01]

Originally Posted by fusion210

I really like my plexiglass ones made from some scrap material. They're stealthy.

Mine were worth around 5% for my low speed commute. I thank the faster warm up times, it's hard to have an efficient engine in the winter that doesn't get up to temp. Thanks to all the coasting, it wouldn't even reach 170* in mild NC winters.

I cut them to match the openings, drilled some holes and used zip ties to attach them.

5% is pretty good considering it was free.

I don't EOC until the engine gets up to 180* or so. But, it only takes 5 minutes to hit that.

[sarguy01]

Got out into the garage tonight! I made the upper grill block. The paint is going to drive over night. I am only zip tying this one to the grill. Nothing fancy.

Note to self: Even though I KNEW that flashing would be sharp, it took me several cuts and some blood to remember to put gloves on. Next time, I am getting corrugated plastic like everyone else.

[ssnsvibe09]

The changes allowed it to peak at 189 on hills here. However I am still sitting at 32 f for ambient temperature. I did notice that i lost about five degree of intake temperature difference. with the upper grill block i was enjoying over 7 degrees and it is only 3. I am slowly working on a plan to plumb in tubing from the exhaust manifold heatshield to my intake to improve those numbers.

[aerohead]

Originally Posted by ssnsvibe09

I had two upper grill blocks install and the lower one on for a few days but the temperature was hitting 200. so I took off the lower one, to lower the temperature down to around 185, but your recent posts had me thinking to swap things around.

This morning I reinstalled the lower one and removed the right hand side.

Where is the temp. sensor monitoring location ? Some cooling systems run at up to a 'normal' 255-degrees F.

[suspectnumber961]

With my 03 Focus I have an upper grill block and 3 removable clip-on blocks for the lower grill for use in winter....which vary the opening. I also use a plywood front "pan" to streamline and divert air under the engine.

I aim for over 200F coolant temp from the readout on a Scangauge...which I always monitor. I also installed an LED to indicate when the coolant fan runs. With the Focus...the coolant fan comes on at 233F and goes off at 222F. Temp very rarely gets above 233F...before going down.

Have run this way for maybe 2 yrs or so. Am somewhat concerned by the heat under the hood causing cooling hose failures...the newer hose materials will not show deterioration...the rubber and fabric will just get weak to the point of failure....heat is the enemy. The LED indicator will give me a chance at least to avert disaster.

IF a hose goes...you won't see steam...since it will blow back behind you. How do I know...had this happen with a couple of cars...head gasket time...at a minimum.

In summer...I sometimes have the fan come on in town in slow traffic. Will be removing a strip of foam tape under the front edge of the hood to enable a bit more fresh air intake this summer.

[pjbgravely]

A few notes from my testing.

I found with my car that the lower intake was doing all the cooling work and that the upper actually let air back out at high speed. I blocked the upper and my cooling improved. I believe the top grill is for idling with the A/C on which I never do. YMMV

If you want maximum cooling then you target temp should be a degree or 2 above your thermostat temp. The thermostat opens and closes to maintain proper engine temp.

If you want to control your engine temps with air only and no thermostat ( this will increase engine warm up time) remember that you need to keep the same restriction that an open thermostat creates in the water flow. Cutting out the working parts and leaving the frame is one way to do this. No restriction will result in less cooling as the water flows though the radiator too quickly.

[xecute]

Scan Gauge Rulze!
I'm looking at a 70% drag reduction, so seeing what you've done is a lot of fun.

I'd agree that at least a 10% reduction in drag has happened, probably 12% as one post stated earlier.

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.

On an "apples for apples" basis where there was no frontal area change, the 79 Mustang Daytona and 80 Mustang IMSA show cars used a full polycarbonate front cover, one smoked, the other a clear and painted item. In the old quad headlamped cars, such a thing would slam the total drag by about what I've estimated to be 15% (from about 0.45 to way under 0.39). Back in pre 1984 dark ages (before the Lincoln LSC got the fed tick for flush lights and the old World War Two sealed beam rules were enforced), it was easy to drop 15% off the nose just with those two light and grille blocker mods.





For emperical info from Audi, On a 40% cd reduction (approx 0.44 to 0.32 or 0.30 depending on trim), for example, in instances where an engines automatic transmission spec and gearing wasn't changed, a same spec 135 hp engine package, such as in European version of the slick 0.32 Audi 5000, it saved 11 % fuel on the highway cycle, 2.1 US mpg at 56 mph, and 2.6 mpg at 75 mph, and it got an extra 5 mph top speed over the 0.44 predecessor.

So 40% reduction was a nominal 11% fuel saving in that 56 to 75 mph instance.
20% would have been 5.5%
10% would be around 2.25%.

In my opinion, the stock aero drag would be going down 0.03 cd numbers, or a 10% drop in cdA to get a 2.25% fuel economy reduction at 56 to 75 mph, based on empirical data.

You can do coast-downs to quantify the effect, but a fuel economy saving like that is at the very least a solid gold 10% reduction in road load at 50 mph.

Well done!

[sarguy01]

Originally Posted by xecute

Scan Gauge Rulze!
I'm looking at a 70% drag reduction, so seeing what you've done is a lot of fun.

I'd agree that at least a 10% reduction in drag has happened, probably 12% as one post stated earlier.



On an "apples for apples" basis where there was no frontal area change, the 79 Mustang Daytona and 80 Mustang IMSA show cars used a full polycarbonate front cover, one smoked, the other a clear and painted item. In the old quad headlamped cars, such a thing would slam the total drag by about what I've estimated to be 15% (from about 0.45 to way under 0.39). Back in pre 1984 dark ages (before the Lincoln LSC got the fed tick for flush lights and the old World War Two sealed beam rules were enforced), it was easy to drop 15% off the nose just with those two light and grille blocker mods.

For emperical info from Audi, On a 40% cd reduction (approx 0.44 to 0.32 or 0.30 depending on trim), for example, in instances where an engines automatic transmission spec and gearing wasn't changed, a same spec 135 hp engine package, such as in European version of the slick 0.32 Audi 5000, it saved 11 % fuel on the highway cycle, 2.1 US mpg at 56 mph, and 2.6 mpg at 75 mph, and it got an extra 5 mph top speed over the 0.44 predecessor.

So 40% reduction was a nominal 11% fuel saving in that 56 to 75 mph instance.
20% would have been 5.5%
10% would be around 2.25%.

In my opinion, the stock aero drag would be going down 0.03 cd numbers, or a 10% drop in cdA to get a 2.25% fuel economy reduction at 56 to 75 mph, based on empirical data.

You can do coast-downs to quantify the effect, but a fuel economy saving like that is at the very least a solid gold 10% reduction in road load at 50 mph.

Well done!

Thanks! Also, I appreciate the examples. Very good info. At 65 mph, watching the Torque app seems to yield slightly higher mileage than before the mods. This isn'f proof, but backs up the ABA testing I did.

Also, after filling the tank last night, seeing the mileage is probably more proof that the grill bocks are working. The tank was 40.6 mpg, without EOCing. I EOC'd the last two tanks and got around the same mileage.

Next mod, warm air intake, with ABA testing of course...