The Holes!

[Ecky]

Right, I imagine this helps fill the low pressure zone in the wake, but it probably also does it in a very turbulent manner. A kamm or boat tail + belly pan would be ideal, but there are plenty of situationally effective less than ideal solutions.

[JRMichler]

Were the before and after tests on the same road in the same direction with the same wind and same air temperature?

[compdrag]

Originally Posted by JRMichler

Were the before and after tests on the same road in the same direction with the same wind and same air temperature?

Yes they were

[Xist]

Bell mouths and ducts

[compdrag]

Well just a quick update, I don't drive a whole lot so everyday I get more on the tank is a good thing. So I'm at around 280 now and still above a 1/4 of a tank. My UG will be here tomorrow so I will be able to do runs with cruise control to see what the differences are with and without the holes. Stay tuned!

[freebeard]

Originally Posted by Xist

Bell mouths and ducts

Do go on...

[compdrag]

Ok first round of numbers are in, and let me say I'm not saying the holes did it, but numbers don't lie. I will be repeating the test just not today. Ok I did two runs once with holes and one without. I used Duct tape to cover up the holes with multiple layers to unsure no wind got through. I took the same route and I went 60 mph for both tests. I neutral coasted on both off ramps and did 3k shifts when getting back up to 60mph.

Here is the start of the test notice the 0 in the trip gauge.


Here is after the first test 38.2 MPG with holes.


Start of 2nd test zero'd out.


Here is after the 2nd test at 37.6 MPG


ok now onto the performance gains I know its not as big of a deal I will be doing this test again also. I did not make it to 100mph like I wanted to only got up to 80 and then shifted to 5th getting back to 60mph quickly

run without holes


Run with holes gaining about .45 tenths of a second on speed and .3 tenths on 1/8 of a mile 1/4 I wouldn't count because I wasn't there by the time I hit 80.

[compdrag]

oh on another note I'm at 370 miles on the tank, and I still haven't hit the fill light yet which is where I fill up at so i'm looking at probably 33 mpg by the time it does. After getting the UG I've be able to get 36mpg after a 60 mile trip.

[BamZipPow]

I noticed yer running open loop?

[compdrag]

Originally Posted by BamZipPow

I noticed yer running open loop?

Its only open because the car was not running when I took the pictures. I didn't want to sit idling while I reset the trip and snapping the photos, and adding and removing the tape.