96-00 Civic Hatch Spoilers

[thebrad]

The EK aero mods bar has been set:




While some of these apply specifically to 99-00 models, and others to the coupe/sedan. We can all steal a little from here or there.

[MetroMPG]

Lostcause is bang on, as usual.

To reduce drag on a hatchback, your spoiler mustn't extend upwards of the imagined line/arc continuing the roof line, in profile view.

These Volvos are a good illustration:

With their C30 "Efficiency" model, among several aero enhancements, they reduced the rear spoiler angle from the regular model, essentially turning it into a roofline extension (extending the slightly downward slope):



(source)

vs. original model with higher cD:

[brucepick]

Now if only Volvo would offer the C30 in the US with a fuel-thrifty engine instead of the 227 HP 5-cyl turbo.

[RPM]

Please take a look at these accessories from Honda Japan. I'm pretty much positive the side flaps are a good addition but wonder about the mid-trunk spoiler.

Do you think it allows for air flow reattachment and a smaller wake?

[MetroMPG]

Interesting. The top & sides do look proper, but you're right to doubt that lower spoiler. It's too short to do anything useful except gather dust. I think it's very safe to say it would be fully within the turbulent wake.

[lunarhighway]

i'm not sure if that lower spoiler doesn't do anything. dont forget the flow comming of the C pillars is going inwards, so the sides of the lower spoiler will have some effect. but even so perhaps turbulet flow is not beyond guidance.

also it reminds me of the old citroen ax wich had a spoiler like projection in the same place and a much steeper rear window


the AX has a Cd of only 0.31 wich is rather great for a tiny hatchback so there must have been quite some earo research on it. this spoiler was actually part of the metal hatch so they must have been pretty sure it was doing something right as a flat trunk would have been cheaper and easyer to make.

edit:
come to think of it this car looks very similar to swift/metro's so this sort of thing might be wort for metro owners to look into.

[hondaworkshop]

? Front window 'wind-sashes' are helpful for CD?

[RPM]

Originally Posted by hondaworkshop

? Front window 'wind-sashes' are helpful for CD?

They most definitely aren't. But I wasn't talking about them.

[hondaworkshop]

Ohhh, I see the side flaps on back! I'd like some of those myself!

[thebrad]

Nice find RPM!

Kind of funny how all the aero junk on the hatch makes it look like a Del Sol...
I wish they could have made it into one full assembly instead of three different parts, but I am going to begin searching for it. Probably going to have to pay a ton for it just because it's "JDM"