Fuel Economy, Hypermiling, EcoModding News and Forum - EcoModder.com - View Single Post - Failed segmented boattail experiment using drawer slides

Cd · 02-03-2023, 08:57 PM

Piwoslaw : Appreciate that.
Even if I do get this thing fully road legal, I don't drive much at all so wouldn't be able to do any testing.

Aerohead :
There would be a huge amount of drag where the louvers are.
The underside would also most likely not be smooth enough for good attacment all the way to the rear.
I planned a diffuser and a venturi tunnel, but it's a pain working under the car - especially since I live in an apartment and don't have a garage.

I planned to add window screen over the louvers. This would help the drag, but I'm not sure how much.

Overall, I would expect a cD similar to your truck, but much higher because of the louvers.

When the 5th generation Civic came out, Honda qioted a .32 cD for the Civic coupe, and a .31 cD for the hatchback .
However, Honda quoted a .36 cD for the coupe in 1996, when talking about how the Civic cD compared to the Insight.
The shape was identical to the 1992 - 1995 model though, with only the addition of a different headlight design.
So I'm guessing my cars stock cD to be at closer to .36 to start.

02-03-2023, 08:57 PM	#30 (permalink)
Cd Ultimate Fail Join Date: Feb 2008 Location: Austin,Texas Posts: 3,585 Thanks: 2,872 Thanked 1,121 Times in 679 Posts	Piwoslaw : Appreciate that. Even if I do get this thing fully road legal, I don't drive much at all so wouldn't be able to do any testing. Aerohead : There would be a huge amount of drag where the louvers are. The underside would also most likely not be smooth enough for good attacment all the way to the rear. I planned a diffuser and a venturi tunnel, but it's a pain working under the car - especially since I live in an apartment and don't have a garage. I planned to add window screen over the louvers. This would help the drag, but I'm not sure how much. Overall, I would expect a cD similar to your truck, but much higher because of the louvers. When the 5th generation Civic came out, Honda qioted a .32 cD for the Civic coupe, and a .31 cD for the hatchback . However, Honda quoted a .36 cD for the coupe in 1996, when talking about how the Civic cD compared to the Insight. The shape was identical to the 1992 - 1995 model though, with only the addition of a different headlight design. So I'm guessing my cars stock cD to be at closer to .36 to start.