Mustang kammback help

[California98Civic]

Originally Posted by winkosmosis

The Mustang's rear window is 22 degrees according to my measurement

If it is like my about 22* window there is turbulence and a bit of separation toward the lower half of the window and trunk lid. See this wet tuft still:

The spoiler is there possibly to try and correct it, and possibly to produce downforce. Either way it must be producing some drag of its own. A clear Kamm that replace the 22* window and spoiler with a 14/15* clean slope would probably get the big ecomodder cheer. It could look cool too, I would think.

[Floordford]

The closest thing to a tuft test has been rain. And there is definitely separation. It starts coming back to the rear window on both sides and does kind of a V shape. l\ /l
Ive thought of vortex tabs but ive seen many tests where they accomplish little.

By the way, thanks CFG83 for doing the image mash up. It gives me a good general picture of what needs to get made.

Thank you California98Civic for the compliment and help.

[Floordford]

Originally Posted by winkosmosis

The limit is 30 degrees, and the Mustang is within that limit, plus it has a gradual curve. I think it's fine the way it is. I'd be surprised if you got a significant improvement from making your beautiful car ugly.


Instead, get rid of the fake side air intake and give it an air dam.

So do you think a flat drag style wing would accomplish the same thing? It might look more at home on the back of a Mustang anyhow. But it would make it look like a full on drag car. And I have thought about deleting the side scoops and testing with and without the fake hood scoop.

[lunarhighway]

i think for the effort en material involved in a camback you could build a nice front and rear, undertray, and smooth out the center secion as well... i think when aeromodding you best go for the most unaerodynamic sides first the underside and the grille, smooth out the underside reduce or completely block the grille opening, see if oem style dams might look appropriate... all gains that don't alter the look of a car much

[California98Civic]

Originally Posted by Floordford

So do you think a flat drag style wing would accomplish the same thing? It might look more at home on the back of a Mustang anyhow. But it would make it look like a full on drag car. And I have thought about deleting the side scoops and testing with and without the fake hood scoop.

I wouldn't do that. I tried it. A flat Bonneville style spoiler, slightly angled up. I hit the template just fine. In an ABAB test I lost MPG. Note too that winkosmosis corrected the post you're quoting. Personally, I love the suggestions you are getting about working with a front air dam, undertray, and side false intake deletes... these are low fruit that will almost certainly generate gains without changing your clean ride's look much at all. Even if you keep the side intake body moldings, do the other things. Those mods are on my own list. If I had not gotten distracted into these time consuming tail-end projects, I might have done the airdam and rear under tray by now. One of the coolest things about these aeromods for a car like yours is you can tell folks who ask that they produce better FE without reducing horsepower and therefore also increase your car's top speed.

[Floordford]

Ive wanted to do an under body tray but have yet to be able to find low cost 4'x8' coroplast sheets. Te cheaper it is the sooner it will pay for itself. Ive got a few other things id like to try if I had a good amount of coroplast or cheap sheet aluminum.

I lately did a wiper and antenna delete and got 32 highway. Then on the exact same stretch did a passenger mirror delete, upper grille block, adjusted my cold air intake to take in only hot underhood air and I put foam around the headlights to gap seal. Those mods achieved 34mpg highway. Thats in the area of 50% improvement over the EPA 23mpg highway it gets from the factory. Im wondering if it can get to 38 on the highway. 40 may be too optimistic.

[winkosmosis]

Whoa, you really got to 34mpg highway? Was that downhill with a tailwind?

[Floordford]

Originally Posted by winkosmosis

Whoa, you really got to 34mpg highway? Was that downhill with a tailwind?

Well it was a 160 mile down and back from Nashville to the Alabama state line on I65. Its a fairly hilly drive so some of it I was able to EOC. My speeds for most of the trip was 55-58. But a few times I would speed up as I wend down a hill so my coast would last longer. Back in March coming back from the Gatlinburg area going to Nashville I did 33mpg with the cruise control on 60. But it kind of doesn't count seeing that it was just one direction.