Silverado aerocap build thread

[ChazInMT]

Ecomodder Mythbuster Thread

MazdaMX, It has been discussed here ad-nausium. It is the world consensus that the only place it has worked is on Mythbusters.

If you read the Hot Rod article I linked above, you'd know, the guy doing the testing there is no slouch in the aero world, for him to say the dimples are no good means a lot.

[MetroMPG]

mazdamx640, that Mythbuster's "test" was full of holes and you should be wary of the results. See this thread: http://ecomodder.com/forum/showthrea...-vs-10658.html

[Fubeca]

Well Charlie (ChazInMT) stopped by on his way out East and we had a good time chatting over lunch.

Funny - neither of us really seems to get much interest in our caps while out and about. But it was kind of interesting to see a few people react when we were parked next to each other and running up and down the freeway together.

Anyway - we decided to do a little tuft testing to make Darin happy

We went up and down the highway about 3 miles - the first video is much better than the 2nd.

http://www.youtube.com/watch?v=4W-zGJHIhdQ

http://www.youtube.com/watch?v=toRQ7PyqXLg

[BamZipPow]

It looks cold out there...brrr!

[ccrider]

hey why wasn't i invited to the aerocap lunch? oh i get it this must have been a GM aerocap lunch. well when mjboks gets his cap done me him and aerohead are going to go out for a Toyota aerocap lunch and you GM guys aren't going to be invited. haha just joking.

Charlie what find of gains did you see on your trip across the country with your aerocap? i am actually in Florida now. i just logged 4 tanks from my trip but i had 600 lbs in the bed so the fuel economy wasn't that great.

i am hoping to get some tuft tests and a ABA test done.

[Fubeca]

It was kind of ad-hoc and in Wisconsin, but next time you're invited!

[MetroMPG]

Originally Posted by Fubeca

Anyway - we decided to do a little tuft testing to make Darin happy

Ha! Well, you succeeded. Thanks for posting that.

Notice anything interesting in your video?

And can boat tailed econoboxes come to the aero lunches too?

[Fubeca]

Next time - we'll post up - any and all are invited

Unfortunately I was driving and didn't get to see the live tufts and both videos are not incredibly clear.

I did notice that the tufts at the gap were being pulled in on the side making me think the topper extends just a little too far.

I was surprised to see the distinct upward flow on the sides.

I was happy to see attached flow all the way down.

I was also surprised at the behavior where the side are meets the top air. I was expecting some turbulence there but it appears that the radius allows the air to join nicely.

I'm hooked now and would like to get some more comprehensive video to better visualize the air flow.

[MetroMPG]

I was happy to see good attached flow too. I couldn't make out what was going on on the top by the top/side transition. Glad you saw nothing unusual.

Yeah - the upward flow on the side was what caught my attention too.



We saw evidence of the same thing in the Ford Ranger aero cap video.

Flow will travel from high to low pressure, and above the arc of the cap is lower than the sides, so that's what we're seeing. If the cap were tapered in plan as well as profile, those side tufts would probably be closer to horizontal. (You can see this in the tuft vid of my boat tail.)

[Big Dave]

Are climbing tufts a good thing or is this the "C" pillar vortex climbing upwards on its own?

I would think that anything lifting mass would require energy.

Would a "fence" cut off the climbing vortex? You see fences a lot on STOL plane wings to control vortices.