Aero testing the short cover

[drrbc]

Finally got around to a 70-50 coast down ABBA. Didn't go well.

After 1.5 hours of the test (started t 11pm on a straight stretch of 288 near Angleton), it was finally done. Whoop!

Then I hit the "Stop Data Logging" button on my iPad and the damned thing froze. No kidding. Froze. Had to do a reset.

Gone. All of it gone.

And yes, I was using the latest version of DashCommand, had no other apps open, and had several gigs of free memory.

Fortunately, I had my wife with me and she was using pen and paper with her iPhone as a stopwatch.

And that went something like this:

(coasting down from 75 and counting it off)
me: 75, 74, 73, 72, 71, NOW!

her: Huh?

me: NOWNOWNOW!

her: Don't yell at me!!!

Went ahead and crunched the data anyway and it actually looks like the shorty aerolid did 10% WORSE (70-50 was 10% quicker) than without.

If I get a chance I'll try the ABBA again and save the logs files after each individual run. Maybe the file length was too long. I just don't know.

Anyway, had to do an all-of -the-sudden run to San Antonio late Saturday night and took I-10 all the way. I was tired so I took my time. Also stopped at Buc-ee's for some coffee and the peanut butter fudge.

Did 208 miles in 208 minutes for a perfect 60mph average.

At 22.4 mpg. (per the computer)

But this time there was no attempts to draft- I was just letting everyone blow past me.

So it's not great data, but I think it's helpful nevertheless. I drive better than I used to- stocking foot, keeping an eye on the MAP and instant MPG, making sure the is no one in my rear view mirror, etc.- but I'm FAR from being a "hyper miler". I think everyone should just weigh the evidence I've given for themselves. I'm sorry, but I might not be able to get much better.

But I am thinking about this- what about a 70-90 acceleration test? Lock out 6th so there is no downshift and just WOT from 70 to 90. Any thoughts?

Once again: 2013 F150 SCrew, 5.0, 3.55, 32's, 2 inch drop kit, Volant CAI, Magnaflows, and an MPT 93 octane eco street

[Xist]

I am sorry that did not go as well as you hoped, your bit of dialogue gave me a chuckle, though.

I tried getting my ex-girlfriend to help me with some things and I never understood why it was so difficult. One time I was just fixing my laptop on my bedroom floor, not knowing where else to work on it. I had dozens of screws organized according where they had been in the car, and then she walked right between me and my computer parts, dragging her feet, kicking my screws all over. I yelled at her, she acted hurt, asked why I was doing that on the floor anyway, and then said "All of the screws are still there. You did not lose any!"
"You could not possibly know that!"

I broke up with her. She called the police and sued me.

Good times.

[drrbc]

Originally Posted by Xist

I am sorry that did not go as well as you hoped, your bit of dialogue gave me a chuckle, though.

I tried getting my ex-girlfriend to help me with some things and I never understood why it was so difficult. One time I was just fixing my laptop on my bedroom floor, not knowing where else to work on it. I had dozens of screws organized according where they had been in the car, and then she walked right between me and my computer parts, dragging her feet, kicking my screws all over. I yelled at her, she acted hurt, asked why I was doing that on the floor anyway, and then said "All of the screws are still there. You did not lose any!"
"You could not possibly know that!"

I broke up with her. She called the police and sued me.

Good times.

Dude, thanks for the reply. I got a new Bushnell ET 6-24X50 (it was an "OMG" type bargain) for a BAR .308 that I need to mount. And believe it or not, I JUST NOW put my gun vise on "her" kitchen table (it's too hot to work in the garage) when she came home from shopping with a girlfriend.

So I put the vise back up in the garage. She's going out of town in a few days anyway, and after your post I thought maybe its best I not risk things. Well, at least with anything of that caliber.

And the little "Thanks" button only lets me thank you once and your reply definitely deserves at least a couple with maybe a "thumbs up" or two. Just wanted to let you know.

[UltArc]

That's a good looking truck. I love when ecomods look good, and when non Eco vehicles get modded. What was the test like? I mean, was there traffic? Did you do both directions and average? Any change in temp? Anything that may have influenced it? ABBA seems like a decent way to test, but I still prefer ABABA myself.

[drrbc]

Originally Posted by UltArc

That's a good looking truck. I love when ecomods look good, and when non Eco vehicles get modded. What was the test like? I mean, was there traffic? Did you do both directions and average? Any change in temp? Anything that may have influenced it? ABBA seems like a decent way to test, but I still prefer ABABA myself.

Perfect weather, 2mph from the south. I selected a section of 288 that was almost perfectly North-South with a 5-6 mile run without overpasses. It was a Sunday night a week ago, so traffic was minimal. Still, when there was traffic, I didn't make a run until I thought that if I did catch the car in front that I'd still be at least 10 car lengths behind when I popped into neutral.

Made 3 coast downs north, and three south. Took the lid off and repeated that twice more. Put the lid back on and did the north/south runs once more.

Also, I did go thru and screenshot the before and after weather and there was no significant change in pressure or wind direction/speed. When I got out to take the lid off and replace it I can tell you there was no air movement at all both times. And each time I got out of the truck my glasses fogged over immediately.

And I really can't think of anything that could have changed the test parameters that much, which is really, really disappointing. The thing took 7 or 8 builds to get right; it's durable, safe (didn't rip off at over 100mph), and shows no signs of wear, warpage, or photodegredation. It kinda hurts to think that I can't get a test to show SOME positive results.

I even considered just ripping the damned thing off. I figured even a 5% drag reduction should show something, even accounting for the human (I can't hear, she can't see, and we both love to fight) error. Glad I didn't though, I think that San Antonio trip at least shows I'm on the right track. I guess I'm going to have to do the test again.

Oh, and thank you. That's a very kind thing to say considering my own kids think that it looks funny (the manky little heathens just don't understand art).

[UltArc]

Awesome prefecture's!