Template input for Hyundai F&R improvements

[getzfamily]

So I've been trying to use the aero template to figure out some possible designs to get going on the front and rear of the vehicle:
I could be wrong but from what I've read so far if you can't boat tail then its ideal to cut it off as quickly, or vertically, as possible? In the attached picture the red line may be a possibility for rear spoiler to stick with the kamm roof a bit better (note; my getz doesn't have the mini roof spoiler shown in this pic).

Re. the front I have no idea how to improve in this area given that the template is so far back compared to the front of the car, so I'm looking for some insight from the more experienced here

[freebeard]

The Template is what you call an 'attractive nuisance'. Look at the front-rear view and you see it is a half-circle. It has almost no application this side of extreme solar/human powered race cars. The closest you can come is like the MG 181.


http://ecomodder.com/forum/member-sven7-albums-aero+vehicles-picture3242-mg-ex181-streamliner.html

What you can take away is the relaxed, curved taper to stall separation as long as possible. Your truncation is more of a Kamm-back than a boattail, and would have minimal effect. You could take the existing cross-section at the rear and reduce it stepwise along the Template curve.

You might see more return from a rear partial bellypan, it depends. If you went to the next dotted white line, with side tapers balancing (or counter-balancing) the top taper and dealt with the taillights and hatch access, you should start to see some measurable results. Here are some box cavity studies as an alternative:

[aerohead]

Originally Posted by getzfamily

So I've been trying to use the aero template to figure out some possible designs to get going on the front and rear of the vehicle:
I could be wrong but from what I've read so far if you can't boat tail then its ideal to cut it off as quickly, or vertically, as possible? In the attached picture the red line may be a possibility for rear spoiler to stick with the kamm roof a bit better (note; my getz doesn't have the mini roof spoiler shown in this pic).

Re. the front I have no idea how to improve in this area given that the template is so far back compared to the front of the car, so I'm looking for some insight from the more experienced here

*I think that your car image needs to slid forward to get its highest roof point aligned with the 'zero' mark on the template.
*The K-form,or,'Kamm-back' is any truncated form of a boat tail,but both are rooted in boat-tailing.
*Dr. Hucho might suggest that you essentially ignore the front of the car and go after the rear.
*But if you're unwilling to go beyond the red line in your image,there's not much point in pursuing it.Drag reduction is primarily a function of the length of elongation.Gains come from 'feet',not 'inches.'
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You could idealize every detail on the car and eek out a little benefit but for significant savings she's got to be longer.It's the large wake behind the car which is eating away at your driving dollar.

[getzfamily]

Originally Posted by freebeard

You might see more return from a rear partial bellypan, it depends. If you went to the next dotted white line, with side tapers balancing (or counter-balancing) the top taper and dealt with the taillights and hatch access, you should start to see some measurable results. Here are some box cavity studies as an alternative:

Would you mind sharing the link to the source of that image Freebeard?
I was hoping to avoid any belly work through lowering the car once I've got the rim and tyre choice sorted out (Toying with using a stiff thick line of rubber brush, which will hopefully have low air infiltration, descending from the bottom of the front panel I'm making to restrict as much air as possible from going underneath while avoiding the problem of contact with the road?)

And Aerohead, I know relative to what would be achieved from lengthening and enclosing it wouldn't be as significant but could worthwhile gains be seen from adding length but not enclosing it on the end? Access to the boot is important for my work and enclosing the tail makes that more difficult.

Thanks for the input folks!

[freebeard]

The PDF I originally snagged that from went offline or behind a paywall.

http://ecomodder.com/forum/showthrea...les-32406.html —here Cycle posted a link to a later iteration of the PowerPoint slide presentation. On page 8 is a different version of the same slide. I just downloaded it again to verify it is available.

http://www2.warwick.ac.uk/fac/sci/wm...tion120221.pdf

[aerohead]

Originally Posted by getzfamily

Would you mind sharing the link to the source of that image Freebeard?
I was hoping to avoid any belly work through lowering the car once I've got the rim and tyre choice sorted out (Toying with using a stiff thick line of rubber brush, which will hopefully have low air infiltration, descending from the bottom of the front panel I'm making to restrict as much air as possible from going underneath while avoiding the problem of contact with the road?)

And Aerohead, I know relative to what would be achieved from lengthening and enclosing it wouldn't be as significant but could worthwhile gains be seen from adding length but not enclosing it on the end? Access to the boot is important for my work and enclosing the tail makes that more difficult.

Thanks for the input folks!

Short of a proper boat tail,the open,'box-cavity' is the only other technology Hucho said offered us any gains.
Here's a semi-trailer setup

Here's a VW transporter with a cavity.

A true boat tail might offer a 30% drag reduction,whereas a box cavity appears to peter out at less than a 8% improvement.