Aerocap for a Tacoma Pickup?

[ccrider]

[IMG][/IMG]

[ccrider]

one more of the frame

[ChazInMT]

Looks Great CC. I'm going to be in Peekskill NY in a month, maybe we get together for a Gyro at Tony's Greek in Fishkill and compare notes, and freak people out if they see 2 aerocaps in the same place at the same time!

[winkosmosis]

Originally Posted by mjboks

Just as I expected, not the best aero design.



It looks like it would start separation about 1/2 way back over the cap. It's really too bad this style though hasn't migrated to n.america.

OK I don't like this whole "template" business to begin with, but this example made me realize something. You can scale the template, and it will fit that curve. Then you wouldn't be saying that separation starts 1/2 way back. The application of these templates is completely arbitrary.

[ccrider]

you cant scale down the template if you line up the roof of the vehicle with the top of the template and line up the bottom with the road. all you can do is slide it front to back so it lines up better

[bondo]

I just did a pencil outline of your lid in side view. It is real close to the profile of the one on my Ford, just a little taller in the back. I think it is going to work good. Here is a photo of a yarn test on mine below. You might get some yarn and stick it on your cap. Have somebody drive your truck for you and you follow it in a chase car and study the yarn to see if and where the air may possibly detach.

When I built mine I had zero information to go by. I know how difficult it is also to fabricate something this big by yourself. I have a great deal of respect for all you guys who go for it and build your own aerocaps. Also MetroMPG has my greastest respect for the fine job he did on his tail cone. 15% increase in fuel efficiency is outstanding!

By far the most rewarding thing is getting out on the road with your new aerodynamic article you have build get a resulting reduction in your fuel usage.

Bondo

[winkosmosis]

Originally Posted by ccrider

you cant scale down the template if you line up the roof of the vehicle with the top of the template and line up the bottom with the road. all you can do is slide it front to back so it lines up better

What is the relevance of the height of the vehicle? What if the truck had a 4" lift and bigger tires adding another 2"? Does the optimal slope and curvature change?

No. It still has to be shallow enough for attached flow at a given speed and steep enough to reduce cross section significantly. The template means nothing.

[mjboks]

Originally Posted by winkosmosis

What is the relevance of the height of the vehicle? What if the truck had a 4" lift and bigger tires adding another 2"? Does the optimal slope and curvature change?

Yup, the template is adjusted from the ground. Do a "template" search on this site and you'll find a lot of info about aerodynamics. There have been a lot of research done on this.

[ChazInMT]

I question this too and have a good post on the "Tiger woods meets Ciderella" thread. It seems as if flow is going to separate it will do so when it gets pulled to that 115° point beyond the stagnation point of the shape in question. Check out the post and weigh in whether you think Green or Red.

[ccrider]

chazinmt send me a email when you are in the new york area.

i painted the cap tonight that cost me $15 so the totall cost is up to about $45. tomorrow i will take it on a 200 mile trip hopefully i will see some results.