Originally Posted by kach22i (Post 372207)

To clarify even further, of course the transition should be gradual.

Taking the images posted and estimating with an adjustable triangle on my computer screen, we can see that the angles of inclination do increase.

Automobile 2 - Odds And Ends Photos by kach22i | Photobucket
http://i184.photobucket.com/albums/x...psf7875766.jpg

I think there is a matter of scaling to consider which we should not leave out.

Say for instance we mount a 1/6 scale model of the car to the roof of the full sized car. The Cd of the model should be close to that of the full sized car without the roof attachment, right?

The frontal areas of the full sized car and model will be dramatically different, but the Cd's should be similar.

Now for argument's sake, graph on a "known to work" roof transition without regard to scale.

Automobile 2 - Odds And Ends Photos by kach22i | Photobucket
http://i184.photobucket.com/albums/x...ps6b4c71a4.jpg

My hypothesis here is that when thinking about "scale", be it for a more aerodynamic mirror, roof luggage, trailer or an entire car body, we may have far for liberties at hand than normally accepted following the template at the standard scale.

What the Geo Metro and Pontiac Firefly roof garnishments prove to my eyes, is that re-scaling principals are already being applied, although nobody is calling them that just yet.

Originally Posted by ChazInMT (Post 372259)

Yeah...No.

I thought the same thing once.

At the end of the day, we're not running scale models through the air, we're running full size cars. The Template is designed to be under the wheels and at the top of the highest point of the car, because that is what the gross volume of air is being affected by. Garnishments will obviously affect the overall shape and thus the Cd, but we cannot shrink the template onto small features and do elemental analysis on them to see if they'll optimize the entire shape.

I had a hard time with this myself a few years back and really thought as you do, and when I came to the realization that I was wrong, it sort of set a good fundamental understanding of aerodynamics for me which has not changed since. This whole conversation took place HERE.

Of course it is entirely possible that I just misconstrued what you were trying to say, and if so I apologize. These are good talking points worthy of hashing out for sure if we are to come to a good understanding of how to optimize the shapes of our vehicles to reduce drag.

Oh, and the Reynolds Number, which I'll admit is a bit of a mystery to me in detail, but the basics of it state that: A 1/6th scale model may indeed have a very different Cd than the full sized version. That's my take away, maybe someday I'll edumacate muhself on the vagaries of it, but for now, I'll just understand it to know that scale definitely changes things.

Originally Posted by kach22i (Post 372312)

Interesting, thank you for providing the link.


An important goal indeed, but in this situation he (the original poster) wanted the flow to stay attached. Maybe his goals should be re-examined.


I will look into this.

Below is an example of what I had in mind, not saying it is the best thing to do to obtain an aero-design. Just saying if adding on, maybe scaling down the template is better than nothing at all.

18 Gurney Bubble $35
Cushman Competition
http://www.cushmancompetition.com/GT...y_Bubble_1.jpg

Panoramio - Photo of Gurney bubble on a GT40
http://mw2.google.com/mw-panoramio/p...m/65873497.jpg

Reproduction GT40 for sale in California - SB100 *SOLD* - GT40s.com
https://lh6.googleusercontent.com/-q...0/DSC_9926.JPG

Originally Posted by ChazInMT (Post 372447)

You misunderstood me I think. I am saying that attached flow will always be required for the ideal aerodynamic car, but, It is a consequence of good design, it is not the main goal. Everyone gets all hairbrained about attached flow like that is the only thing we need to accomplish in order to achieve aerodynamic nirvana, but it is not. Of course he wants attached flow, he probably has it now, but just because the flow is attached does not mean it is optimized. You need to carefully consider how fast the air is being asked to close in behind the shape, if it is too fast, it creates low pressure. If this low pressure is in close proximity to an area of high pressure, the air will move up from the high to the low and if strong enough a difference, will set a vortex in motion which will be a real drag.

And Yes, If you have something sticking up on a car, a mini template is the best way to mitigate the damage done. I always look at AC units on RV roofs and think "That should be mini-templated". But, when you look at the major structures of cars, like the trailing edge of the roof, you can't just start with a mini-template there and expect it to be optimal, it probably wouldn't hurt, but it won't minimize the drag for the space that it takes up.

Again, I'm not saying here that the existing Kamm is a disaster, just that it is not optimal. It is giving back 60-70% of the potential gain for a structure of it's size and type when it could be doing 100%

Originally Posted by kach22i (Post 372492)

This is how my roof wing (see link in signature) works.

I had not really considered that if drawing too much air downward via pressure differences that a large drag causing vortex could be formed.

To tell the truth, it is difficult to see large trailing vortexes in wind tunnel smoke streams.

And CFD models mostly look like irrelevant swirls of psychedelic colors to me.

The CFD models based on pressure (verses flow) are even more ambiguous to my eyes.

Essentially everything aft of the car just looks like a mess to me, but I am slowly learning the differences.

Originally Posted by Sven7 (Post 372545)

Just, whatever you do, please refrain from scaling the template like this. It will just confuse others and help to concrete bad habits in others. If you're unsure how to use it, re-read this thread.

Not trying to get all down on you or anything. I just want to make sure that the info we're posting is going to be useful to others who may happen upon it.

Originally Posted by Xist (Post 372557)

How much for a Hammond bubble? http://db2.stb.s-msn.com/i/D2/76415F...5D3EC99A7E.jpg

Sven7, who made that image? Did you properly discipline them?

Originally Posted by kach22i (Post 372639)

When you say useful, you mean following conventional wisdom, right?

As pointed out in this thread there are several Japanese hybrids which truncate the arc over the roof at a greater angle than "our template". The reason for this is still being debated, and that debate is healthy in my opinion.

Back when we talked about altering the roof of a +2005 Mustang to fit the template the idea of re-scaling the template for the canopy somehow gained more acceptance than in this thread.

My goal in examining the re-scaling of the template is to discover the exceptions to the rules, not to redefine the rules or aero template.

There is something to be learned here, I just haven't quite figured out what yet.

The Gurney Bubble, wheel blisters and so forth are part of a micro aerodynamic package inside/outside of the overall general aero template.

How large is "micro", and may it include an entire passenger cabin canopy?

Still learning the answer to that one.

Originally Posted by Sven7 (Post 372652)

Those interested in Geo Metro Kammback advice can skip this post.



I take it Conventional wisdom would be the culmination of decades of aerodynamic research by seasoned professionals? Then yes, I would suggest sticking to conventional wisdom.

Yes, we do know each car is designed and modified on a case-by-case basis, HOWEVER, major changes such as the ideal angle of the rear glass are taken on by seasoned professionals in full-size wind tunnels in huge design and engineering facilities. They are tested and re-tested. They are built from the ground up to be a cohesive form.

Adding a kammback to an existing car without wind tunnel testing is an entirely different beast and we need to play it safe, using tried-and-true methods and forms in order to make things work as well as possible. We need to build off of known values and "conventional wisdom" to be reasonably confident the things we build will work as intended.

Throwing your hat in the ring because you think maybe unconventional changes might work in the right circumstances is not productive in this thread. Don't post an unfounded opinion as some sort of "alternate" fact.



Until you test these theories and exhibit some form of real-world expertise on them, please refrain from posting them in otherwise serious threads. Moving drawings around in Photoshop does nothing to advance aerodynamic theory and only serves to confuse those who don't know better.

If you haven't learned what you're trying to learn it might be good to learn it before trying to teach others.

We have the Unicorn Corral for spitballing about this kind of stuff, and I personally think that's where this "debate" should stay. Until it's proven.

Until then, we have no reason to believe that the template is not serving its intended purpose. We have no reason to discard it or modify it. Next time, if you're thinking about using the template improperly, just STOP and think about what you're doing.

Just follow WWJD (What Would Jaray Do). Imagine having to explain to Paul Jaray why you're doing what you do. Saying "it looks like it'll work" or "why not?" isn't good enough.

Originally Posted by Sven7 (Post 372654)

Kach22i.

Seriously, we do airflow testing here at work and some stuff comes out the exact opposite of what you'd think. I obviously can't go into detail. Just be aware that in many aero circumstances, how a thing looks has little bearing on how it actually works. If you're trying something that deviates from conventional wisdom, you need to test it.

Originally Posted by Xist (Post 372664)

Can you give me any examples? Just whisper into my microphone--I mean, my ear!

I think that it was Aerohead that said that in a windtunnel, the air going over the trunk of a 914 actually flowed forward!

Stuff like that?

I have seen this diagram several times lately and when Aerohead shared it in http://ecomodder.com/forum/showthrea...rag-25845.html I responded:

and he answered:

http://i1271.photobucket.com/albums/.../drawings2.jpg

You guys seem to have agreed that attached flow is not enough, but would you have even that much if the angle is too steep?

Originally Posted by kach22i (Post 372706)

Tyler, next time you feel like coming off as some snotty kid and know it all, just stop and think about it - seriously.

There have been several recent postings on the late 1970's and early 1980's work NASA did at out at Dryden. It's information like this which investigates things outside an idealized 3D shape which I find most useful to our DIY backyard applications on real world vehicles.

http://i184.photobucket.com/albums/x...ps2aae42fc.jpg
http://i184.photobucket.com/albums/x...ps468f9c5b.jpg

The Dryden truncated boattail has been discussed many times in this forum without anyone suggesting the that template is in error. I don't see why it cannot be done again.

One of many NASA/Dryden PDF's posted in the forum:
Access forbidden!

Photo Gallery on several of their research projects"
NASA - Dryden Image Gallery

EDIT-1 ............image added:
Automobile 2 - Odds And Ends Photos by kach22i | Photobucket
http://i184.photobucket.com/albums/x...psb4f53ba8.jpg

Originally Posted by aerohead (Post 372708)

If the contour is steeper than the 'Template' it puts the boundary layer in a very precarious position.The sudden pressure rise will trigger separation and your wake begins right there,with a tremendously low base pressure,killing you with pressure drag.
The 1922 Klemperer' streamlined brick runs a 'fast' rear contour but it won't go below Cd 0.15.It's right at 22-degrees and it gets there pretty fast.

Originally Posted by ChazInMT (Post 372721)

Kach, apply the template however you want for yourself. When you apply it wrong in open forum, don't expect us all to fall all over ourselves heaping praise on you for your insightful genius. I have patiently tried numerous times to explain where your thinking is in error. Your post #33 is proving to me that you disregard what I say and are unwilling to listen to anyone but yourself. I'm done trying to help you.

Originally Posted by kach22i (Post 372766)

ChazInMT, I never said that you were wrong, Tyler was wrong or the aero template was wrong - remember that.

I've stated that rescaling the template for smaller scale protrusions like the Gurney Bubble works and achieved agreement.

The earlier +2005 Mustang example also caused some people to rethink how the template could be interpreted.

The trailing edge roof spoilers on econoboxes and the roof garnish on pick-up trucks also seems to be cases where increasing the angle of inclination over that of the aero-template (at full scale) works.

At some point you have to admit my discovery of a connection between the template and rescaling has validity. One size in fact does not fit all.

You have seen and noted several Japanese hybrids veering from the idealized 3D aero shape at least in profile, and this raised a question. This very question I have attempted to answer with rescaling exercises.

If you cannot see what is before you, then you are surely blind.

Automobile 2 - Odds And Ends Photos by kach22i | Photobucket
http://i184.photobucket.com/albums/x...ps04978180.jpg

How much more obvious can I make it?

The aero-template works.

Rescaling the aero-template works to some degree, but it is not the maximized application of this tool.

EDIT-1:

A more detailed examination of this body style and rescaling of template.

Automobile 2 - Odds And Ends Photos by kach22i | Photobucket
http://i184.photobucket.com/albums/x...psb93382f1.jpg

Originally Posted by Sven7 (Post 372845)

I try reason and it just bounces off. I'm going to try one more time. This is the last one.

-Gurney bubbles and trailer A/C unit are not applied to the trailing edge of the vehicle.

-New hybrids are designed as entire vehicles, where the designers are able to tweak and test virtually any part or surface of the vehicle.

-There are more factors in overall Cd than the center profile. Tumblehome, mirrors, plan taper... many if not all of these are adjusted and tinkered with in the design phase of high-efficiency cars.

-The only thing the OP is changing is the trailing edge of the greenhouse.

-You're taking a lot of liberties with the NASA truck, suggesting in one image that it is simply 22 degrees and in another that it matches a scaled template.

-The Volkswagen Golf was designed in the early 70's and was by no means an aerodynamic masterpiece. Picking apart the exact curvature from a non-orthographic image is pedantic.

-I've listened to reports from the aero lab at work and can tell you the car needs to be considered as a whole, not just some 30cm long segment on the back of the roof.



Yep.

Originally Posted by Sven7 (Post 372876)

Not yet; you'll want to do this. Seven degrees on the top. :thumbup:

http://i41.tinypic.com/ayubuq.jpg

And yeah, the longer the better. When you revise it post up some more pics!

Originally Posted by Xist (Post 372892)

I will repeat that filling the wake seems to provide benefits, but should not achieve the full potential.

Originally Posted by kach22i (Post 372993)

I don't think you are that unobservant, so I have to assume you enjoy being a spit wad. In one image I show it does not exceed 22 degrees, in the other that it's a close match for an extremely scaled down version of the template.

Is this what you would rather see?
Automobile 2 - Odds And Ends Photos by kach22i | Photobucket
http://i184.photobucket.com/albums/x...ps8e809ac3.jpg

Kind of makes my point and not yours, don't it?


Close enough to a true side view to make my point, I don't see you providing a better image.


I would agree, but this is not an attempt to design a from scratch car body is it?

Here is a thread in which several early discoveries were made leading to my current perspective on things.

http://ecomodder.com/forum/showthrea...ign-18632.html


A response:


Mind you that I was not and am not in 100% agreement with winkosmosis, but taking what he had to say about the importance of attachment can certainly be applied to a scaled down version of the template. We are probably saying the same thing just going about it from a differing perspective or using a different choice of words.

The proof is in the numbers (Dryden Truck and Porsche Cd numbers).

EDIT-1:
Automobile 2 - Odds And Ends Photos by kach22i | Photobucket
http://i184.photobucket.com/albums/x...psc55a137f.jpg

Originally Posted by aerohead (Post 372998)

I would comment that the NASA' Dryden Econoline has twice the drag of the 'Template.'
The Porsche would see a 57% drag reduction.
Neither vehicle could get there using what NASA or Porsche used.
If 0.238 and 0.28 were the ultimate goal,then NASA was able to squeak by Carl Breer's 1934-1/2 DeSoto Airflow,and Porsche was able to match Edmund Rumpler's 1928 Tropenwagen.
Both a great success!

Originally Posted by kach22i (Post 373001)

When you scale down the template, you scale down your success.;)

I have a new catch phrase.:D

Stock Porsche 911.......................................0.28 Cd
Porsche completely redesigns the 911 Carrera
http://images.gizmag.com/hero/porsch...11-carrera.jpg

http://ecomodder.com/forum/showthrea...1-a-13538.html
(1) Standard DeSoto Airflow sedan----------- Cd 0.546
(6)............................Full experimental aero: Cd 0.238
http://ecomodder.com/forum/attachmen...p;d=1277572689

More than one way to get there?

Rumpler Tropfenwagen: Description of the model, photo gallery, modifications list ...
http://encarsglobe.com/data_images/m...enwagen-02.jpg

http://ecomodder.com/forum/showthrea...-6-a-2670.html

Originally Posted by Xist (Post 364651)

For a given body moving through air, does the air itself care the size of the body?

Originally Posted by aerohead (Post 364849)

As far as size,the air doesn't know the difference (My Fortran IV professor would kill me for saying that).The air velocity must match such that 'dynamic similarity',or,'verisimilitude' exists for the body as far as Reynolds number is concerned.
If you found a boat hull which at the height of the Prius,happened to match the contour of the 'Template' you could use it for an 'ideal' body.And narrowing would be a must.
I've tried this with the full-boat-tailed trailer project.You'd want to find a better 'candidate' boat than the one I used.
The only parameter that's critical is the overall height above the ground where the body will be the tallest.Everything is scaled from there.
So with the go-kart,you'd probably use the top of the rollbar as your 'peak' and go from there.But bear in mind that you've got to have 'clean' air coming at the tail,so the kart would have to be completely enclosed for it to function.
I have a 21-foot sailboat hull which will become a 5th-wheel RV trailer.
If I live long enough to do it.

Originally Posted by ChazInMT (Post 373056)

Originally Posted by ChazInMT (Post 373056)

The Aero template is a tool, designed to be used a certain way for best results. It is meant to overlay on a car with the high point on the top of the car at its highest point, and the bottom chord at the bottom of the tires.

Originally Posted by kach22i (Post 292262)

Audi confirms new model premiere for July 16 centenary celebration
http://images.thecarconnection.com/m...00194215_m.jpg

Originally Posted by aerohead (Post 373004)

If you inspect Hoerner's 'AERODYNAMIC DRAG',his treatment of canopies and blisters(pontoon fenders and separate greenhouse) actually goes in the other direction.
Instead of a 5:1 fineness ratio,he'll recommend 10:1.
It has to do with interference drag and super-velocities created by these individual elements when placed in proximity to one another.
This is a reason for keeping the aerodynamic 'singularity' of the 'Template' half-body rather than 'combination-forms.'
Since the half-body doesn't allow separation and produces minimum shear it's virtually unbeatable for a door-slammer.

Originally Posted by kach22i (Post 373169)

Xist, thank you for taking the time to compile these collections of posts.


I have to slightly disagree ChazInMT, the template is for an idealized 3D shape, and the way it's often used/abused in the forum is in 2D profile only with little consideration for the resulting vortexes. And when used, it is affecting only the upper aft canopy above the tires or pick-up truck bed.

I've explored this issue from several angles in an attempt to gain a better understanding, going from a 2-part body to a 5-part body. See thread linked to below.

http://ecomodder.com/forum/showthrea...tml#post292262


The very idea of adding mass/frontal area to a vehicle such as the type above to meet an idealized template requirement which is not specific to this vehicle's task runs counter to common sense to say the least. And begs the question: then why try it to a common road vehicle?

If there is another way to enclose the wheels of this car without adding mass (area), I'm open to suggestion.

As mentioned in the 2012 Mustang verses the 1978 Escort thread, the frontal area is as important as anything else affecting the drag.

Auto Union Type C Streamline
1:18 Die-cast Model cars and bikes Perth, Western Australia. CMC, Exoto, Carousel 1, Maisto, Hotwheels.

Originally Posted by kach22i (Post 373175)

A cut & paste from the 1936 GM thread:

In short, if you scale down the template, count on making it twice as long.................if it's next to anything else.

Originally Posted by Xist

We were arguing?

Originally Posted by Xist

Say for instance we mount a 1/6 scale model of the car to the roof of the full sized car. The Cd of the model should be close to that of the full sized car without the roof attachment, right?

Originally Posted by Xist (Post 373223)

http://ecomodder.com/forum/attachmen...5&d=1367238665

Whether or not the template scales, I believe that we can start tapering in the bottom as soon as possible behind the rear wheels.

Originally Posted by ChazInMT (Post 373261)

The bottom of the boat tail should not exceed 10° from what I've seen in ecomodder a bunch of times, so your template under the template thing isn't really a good idea.

Originally Posted by aerohead (Post 368955)

I'd maintain the upper curvature as you have it,but for the lower,it will depend on where you begin your diffuser.So it's angle will be 2.5-degrees,or around 4-degrees depending,and you can ignore the red line since you have so much ground clearance to begin with.
You may want to do it in 'installments',to see how you like parking 'n such.If you think you can live with more length then go for it.:)

Originally Posted by ChazInMT (Post 373482)

Here is a link to the new template outline alone in HiRes if you wanna grab it. Made it Just4U.:D

Originally Posted by ChazInMT (Post 373482)

Oh. And you still can scale the thing if you want, and you're right, you'll probably have attached flow when you do scale it, but it won't be an optimized shape.

The template is a guide to optimize the shape of an Entire Vehicle, because when you scale it to fit, the top line of the rear portion automatically becomes the ideal shape the air likes to see for the least overall resistance taking into account the form drag and the skin drag.

Originally Posted by ChazInMT (Post 373482)

And most cars are flat on top for 4-6 feet across, making them something of a wide 2D shape, so you may wanna think about that before you muddy the waters with a 2D vs 3D thing. If you want to build a trike or bike, then you may not be able to make much use of the template because they are taller than they are wide.

Originally Posted by ChazInMT (Post 373482)

Finally, 0.13 is the ideal Cd for a vehicle following the template.

Found it here

Originally Posted by Sven7 (Post 373198)

According to that, this would be correct? Am I interpreting that right? Phil?
http://i43.tinypic.com/2uiuou9.jpg

Originally Posted by aerohead (Post 373520)

..........the Wolfgang Klemperer streamlined 'minivan' of 1922.

Originally Posted by aerohead (Post 373524)

*The 1/6-scale model would not have the same Cd as the full-scale car until 120- mph due to the Reynolds number effect with the boundary layer.
*The 'Template' can only be applied as is shown.It is absolutely contextual.The alignments must be at identical scale and position.
---------------------------------------------------------------------------
*For canopies,blisters,tanks,radomes,nacelles,etc.,you should consult 'AERODYNAMIC DRAG',by Sighard Hoerner.It is the book(s) which is most listed as a reference for such specific information,including Hucho.
*When 'combination',or,'composite' body structures are pieced together,the interaction of each component can create 'super-velocity' effects upon adjoining components and their aerodynamic characteristics are altered by the interactions.
The 'Template' would in no way be appropriate for designing such structures.
--------------------------------------------------------------------------
If you're interested in only limited 'low drag',then there are many options.
The NASA Dryden van would be one.This design would be patterned after DOT vehicle length and other restrictions.It does not reflect an 'ideal' solution,just an arbitrarily optimized one.

Originally Posted by aerohead (Post 221943)

Here's something to consider.
*The lowest Cd for a streamline body of revolution in free-air is 0.04.
* The Template,in free-air,has Cd 0.04.
* When the Template is 'split' in ground-reflection it is Cd 0.07
* When the 'ground-clearance' is cut away from the 'half-body' the Cd is 0.08.
* When skinny wheels are added to it the Cd jumps to 0.12.
* When wheel fairings are arranged around the wheels/tires,the Cd drops to 0.089.

Originally Posted by freebeard (Post 353489)

If you're up for it, try the Squircle. That's the one in the middle here:
http://i.imgur.com/6EYZT.png

Originally Posted by ChazInMT (Post 373482)

I think it lines up great with the 2nd Gen Aero Template.

http://i43.tinypic.com/658krk.jpg

Bigger Version


Here is a comparison of the old template (Green Line) vs the new one (Red). Aerohead figured out a shorter faster template might be a smidge better if you read what he wrote in the Aerodynamic Streamlining Template: Part C thread.


http://i44.tinypic.com/2ajuewy.jpg

Bigger Version

Here is a link to the new template outline alone in HiRes if you wanna grab it. Made it Just4U.:D

Oh. And you still can scale the thing if you want, and you're right, you'll probably have attached flow when you do scale it, but it won't be an optimized shape.

The template is a guide to optimize the shape of an Entire Vehicle, because when you scale it to fit, the top line of the rear portion automatically becomes the ideal shape the air likes to see for the least overall resistance taking into account the form drag and the skin drag.

And most cars are flat on top for 4-6 feet across, making them something of a wide 2D shape, so you may wanna think about that before you muddy the waters with a 2D vs 3D thing. If you want to build a trike or bike, then you may not be able to make much use of the template because they are taller than they are wide.

Finally, 0.13 is the ideal Cd for a vehicle following the template.

Found it here

Originally Posted by kach22i (Post 373629)

In my search to find images of this vehicle I found an intersting website.

Concept Cars and Aerodynamics, 1917-1940
by PETE on MAY 2, 2013
Concept Cars and Aerodynamics, 1917-1940
http://www.velocetoday.com/wp-conten...i-Kel-lead.jpg

Still no signs of the Klemperer in question.

EDIT-1:



Seems to me like there are very limited opportunities to apply the template to existing and typically flat sided (and rectangular wheel layout) automobiles.

I don't think that I'll even bother considering these limitations, as it will never be perfect. Anyone who does a template overlay must be a misguided fool and totally ignorant to boot, right?::rolleyes:

http://ecomodder.com/forum/showthrea...c-9287-13.html


http://ecomodder.com/forum/showthrea...c-9287-47.html
http://ecomodder.com/forum/member-te...-boat-tail.jpg
http://ecomodder.com/forum/member-te...-boat-tail.jpg



Is this the official Part-C aero-Template Cross Section?

Squircle - Wikipedia, the free encyclopedia
http://upload.wikimedia.org/wikipedi...ircle2.svg.png

I've always assumed the Part-C aero-template would look like this (see image below) in front view, but I'm still looking for it.

An Illustrated History Of Automotive Aerodynamics – In Three Parts | The Truth About Cars
http://images.thetruthaboutcars.com/...-FrontView.jpg

Originally Posted by freebeard (Post 373910)

I've been examining my own actions. The loaded terms slipped right past me, but the name questioning stuck out like a sore thumb to me.

So, we're all good then? How about that Morelli Shape?

Originally Posted by aerohead (Post 373899)

*When the Template is coming at you,you see a semicircle minus the area removed for its 'ground clearance.

Originally Posted by ChazInMT (Post 373883)

Kach has come out and basically called the template worthless in all but a very narrow range of circumstances.

Originally Posted by aerohead (Post 373887)

For Klemperer's Cd 0.15 -0.16 model :

Originally Posted by Sven7 (Post 373927)

This is why we always recommend putting large radii on boat tails.

Originally Posted by freebeard (Post 373960)

I've taken the same journey as you—that's what prompted the 'Does it have to be a half-body...' thread. I was asking how much violence you can do to the template and still have it respect you. Nobody addressed it as I had hoped.

Originally Posted by freebeard (Post 374015)

......... and you should see what passes for aerodynamic speculation on other car sites.

Originally Posted by ChazInMT (Post 374033)

All due respect,
Charlie