How far would you go?

[justpassntime]

I want to extend the trunk lip (actually there is none now) on my 87 Accord sedan. Basically a flat flush spoiler to extend the surface of the trunk and aid air flow separation off of the trunk. Looking somewhat like the trailing edge of an aircraft wing. How far is too far? Or is longer better?

I am thinking maybe bringing it even with the rear bumper.

Here are some pics of kind of what I am looking at doing.

Or...

Which is better? Extending the trunk or actually adding a spoiler with air space between the spoiler and trunk lid?

I am not looking for lift or down force.

[NeilBlanchard]

Hi,

Anything that sticks up above the trunk lid will probably add drag. And since the trunk is below the roof, there is not a whole lot of benefit to be had with this sort of mod.

You should modify the front of the car if you want to get an appreciable improvement.

[Funny]

Originally Posted by NeilBlanchard

Hi,

Anything that sticks up above the trunk lid will probably add drag. And since the trunk is below the roof, there is not a whole lot of benefit to be had with this sort of mod.

You should modify the front of the car if you want to get an appreciable improvement.

I'm not an expert, but last time I checked, drag was increased substantially if the laminar flow is not held to the body and released gently off the back with as little turbulence as possible. Getting the aerodynamics correct on the rear-end makes up for a lot of sins in the front. Look at a Cadillac. Don't get me wrong, the front of the car is equally if not more important, but to totally disregard the rear of the car is folly. Thanks to Basjoos and others, Boat Tails and Kammbacks are becoming common mods . Just my rant.

[aerohead]

I recommend you go to Darin's thread on his permanent Kammback for his Metro.In the thread you will find an aerodynamic template we developed to design such things as what you're attempting.If you'll read the explanation and study the template,you'll be able to create a full-proof wing/spoiler/boat tail etc. for the Accord.

[justpassntime]

Thanks for the input guys.

I was thinking the same thing with something sticking up. It would just add frontal area no matter how small or large the area may be.

Will go checkout the Kammback....

Now I'm goin the wrong way. How do you turn this turtle around? Now I gotta go the long way.

[cfg83]

justpassntime -

I wish this would be the way to go, but it's probably just to cover the aero-messy parachute :

Ford Fusion Becomes Hydrogen Hot Rod - 08-16-2007


CarlloSW2

[justpassntime]

I forgot about my old car, thanks cfg.

Actually that thing on the back is an inflatable pool and the thing above it a mini spring board. My kids always wanted to go swimming but we lived by damn dry lakebed.

I used to just drive my Fusion to the store. But I had to drive by a church and they always mistook the 999 as an abstract 666 thing. So to avoid protesters and burning crosses I sold it. I hope this guy takes good care of it.

[MetroMPG]

Originally Posted by NeilBlanchard

Anything that sticks up above the trunk lid will probably add drag. And since the trunk is below the roof, there is not a whole lot of benefit to be had with this sort of mod.

You should modify the front of the car if you want to get an appreciable improvement.

Respectfully, I'd say "not necessarily" on all three counts!

The biggest aero gains are to be had at the back of the vehicle. Extending your roof line following the curvature aerohead referred to would be a good thing.

And It's possible to use a spoiler that reduces drag, even "below the roof line". Check the Pinto on the EM home page: Fuel Economy, Hypermiling, EcoModding News and Forum - EcoModder.com

justpassntime, your mini roofline extension ....



...may just play nicely with a lifted or extended decklid. The only way to know "how far" is to tuft test it. Until you see attached flow (tufts streaming aft) on the decklid extension, you haven't gone far enough!

FYI another thread on this subject (different car) can be found here:
http://ecomodder.com/forum/showthrea...ions-4354.html