Checking on aero stencil placement and spoilers.
 

Howdy, all. New guy here and I wanted to see if the way I placed the aero stencil is about right.
https://i.imgur.com/9GeevKH.png
0 is where I think the highest point of the vehicle is, roughly. Pretty sure the wheels are level.

I ask because I'm considering doing a spoiler (or whatever the technical term is) to "raise" the rear hatch up to the stencil line. You can also see where I did some rough guestimating on what angle the wing would need to be at.

Inspiration was the old Chrysler Conquest rear hatch spoiler. I'd like to do something in Lexan or maybe aluminum.

Thoughts?

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Looks good. :thumbup:

Kammback is the name you seek.

You should consider using cardboard or coroplast to mock-up the kammback for design and testing purposes first before making it out of something more durable.

You can also use the search function for more ideas from prior threads.


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Too little to gain
 

https://ecomodder.com/forum/attachme...1&d=1585792988

Personally, I think the stock angle on the 2013-2015 Honda Crosstour is almost perfect, nearly the same as the 2000 Insight's near perfect hatch angle.

Even the Civics, though messier, are good enough that it is very difficult to improve without a full boat tail. Unless you want to do a full boattail... don't waste time on the rear glass angle.

There are other areas to improve... like imitating the 2000 Insight's fabulous real wheel well covers! What changes have you made already?

This is the spoiler thing I was referring to. Not sure if that qualifies as a full kammback but anyways, semantics.
https://i.imgur.com/2nRqUV3.jpg
Mine would be lower down the hatch, obviously, consistent with where the profile needs to be filled in.

I'm going to give the project a shot, although it'll be the last one. It's more for learning some more fabbing and if it doesn't help (or hinders) it was worth the lesson and off it goes. I don't know that the Insight has quite the same profile as the Crosstour (specifically the angle), although it looks pretty darn close.

Nothing done yet.

Pre-project is measuring coast down time and getting a good baseline MPG (it hovers around 22-23, ouch ouch ouch). I want this project to be data driven and plan on doing one thing at a time, measuring, then moving on.

First project is going to be side mirror replacement with low profile, "F1 style" mirrors. I wanted to remove them completely and go with a panoramic rearview but the blind spots on the Crosstour make it impossible.

Moon covers for the wheels will be next. It took a while to find 18" pie trays that don't cost as much as Moon Eyes anyways but I found them. I plan on drilling and threading the lugnuts for that. I've also got a friend who can help with balancing, if it's possible to balance them afterwards.

Smoothing the front fascia comes next. I work in aerospace and get a lot of free CF and the occasional Kydex. I want to cover the foglights in something clear and heat formable. I also want to put a blank plate over the H emblem and potentially relocate the front license plate holder. I also want to test a radiator blocker on the lower grille. TX gets got but this vehicle is seriously underworked for it's engine capacity and size.

I'd love to do rear wheel covers, if I can find a aesthetically pleasing material. CF or thick lexan would be ideal (I think).

Then maybe the spoiler/kammback, if school doesn't take over my life again. There's also a few creature comfort/driveability mods I want to do that are outside the scope.

Mine are a fade resistant black plastic maybe 4 or 6 mm thick. Very durable, very solid.

How this version looks:
https://ecomodder.com/forum/showthre...tml#post464528

Changes I made to the mounts a year or two ago:
https://ecomodder.com/forum/showthre...tml#post601583

http://ecomodder.com/forum/attachmen...1&d=1421717239

Absolutely love the way you did that. I'm scrounging for just about any plastic I can, since the area needed to do my gigantic rear wheel wells makes any relevant material fairly expensive. And I'll definitely be looking over your build thread for ideas.

Do you think wheel covers and moon eyes would be synergistic? I got my 18" pizza trays in yesterday and want to start building that and collecting data. There's quite a gap between wheel edge and fender edge, so I'm fairly sure I can tuck everything in there.

If the leading edge is sealed to the body it'd be a Kammback. If the gap is just laid flat it would be a divergent duct.

The Kammback works by reducing the area the wake can 'suck' on. I'm not sure what effect ventilating the Kammback would have.

The Template is laid out correctly, but is a harsh rule. It's based on a half-circular cross-section. See the GM EV-1 as a counterexample.

For fender skirts I'm hoarding a [mis-matched] pair of Direct TV dishes.

Ah, interesting. Noted for further use.

Crosstour
 

Your image was taken too close to the car, altering what Honda's design would reflect from a telecamera or blueprint.
What California98Civic presented looks much more accurate for your purposes.
A number of aspirated,rooftop foils (as depicted on the Dodge Conquest) have made it into production vehicles.They don't accomplish anything.And as mentioned,would not effect a change unless sealed airtight against the body.
Even if the Crosstour is incorrect in profile,I don't believe you'd see any appreciable improvement unless you actually extended the length of the car.The experts claim that this is the only true path to lower drag.Of course,you could investigate the cooling system drag,underbody,diffuser,and wheel openings,idealizing everything Honda has already optimized,but beyond that,any meaningful drag reduction would only come from lengthening / boat-tailing.

Yes, probably. A lot depends on your specific car and rims and mods. All the different elements interact with each other and make "one size fits all" simplicity impossible. Experiment. You'll get there. The roll of black plastic I bought was cheap, but it is really sturdy and resistant to solar fading. I hope I posted it specifically in my thread.