I want to build a 100-mpg car (and I want it to look vintage)

[sgtlethargic]

It seems to me that you could and should handle any disagreements you have with information (especially from a long-time member that's been trying to help people) _______________ .

Originally Posted by JulianEdgar

... with respect ...

[freebeard]

Originally Posted by JulianEdgar

But any car shape can be truncated.

That was my approach in the mid-1990s.

[Fat Charlie]

Originally Posted by JulianEdgar

And, "you could do a lot worse than" is, with respect, rather strange logic isn't it? Don't we want people to achieve the best that's possible for them?

Actually, it acknowledges the variety of shapes out there. In tuning a specific engine, the car's weight, aero drag and gearing will all affect what the most efficient tune is. A standard "economy tune" is a good starting place, but it will need to be tested for each unique set of options available. The fact that Porsche can build a low drag car that doesn't meet the template is great- I'd hope that their people with their resources could outperform a dotted line on the internet. If they couldn't, then what would be the point of any of this?

But as a rule of thumb, the template is saying "unlike in tuning, where you can swap or edit maps at your whim, here's a very safe rule of thumb that you can build once". It went on to explain "keep in mind that this is a 2-D ideal, cars are 3-D and better results can be achieved IRL". But If I've got some coroplast, angle aluminum and epoxy to throw at my daily driver over a weekend, I don't have time for testing of multiple designs. My boat tail is probably going to come as close to the template as I can make it.

Listen- I'm one of the people who reads your posts with great interest. People who have the time and ability to do actual developing and testing are the ones who move everything forward, and it's fascinating to watch and read.

But I don't have the same car you have. My car won't benefit from applying your every last refinement to it, because it's starting from a different place- but I can learn a lot from what you come up with.

What isn't helpful is posts like this:

Originally Posted by JulianEdgar

I am thunderstruck. Just gobsmacked. Amazed, astonished, flabbergasted. Words fail me in my sheer astonishment.

The Gen 1 Honda Insight doesn't match The Template.

How could Honda engineers have possibly made this mistake? My gosh; what fools they must be.

The Insight isn't perfect. And it doesn't exactly match the template. Those are both okay. Note, however, that some of the tufts (in the second pic in your post) on the left side of the backglass get a little squirrely, while the ones on the right that have the rear wiper blade acting as a strake are straight. That shows the rear profile is less than ideal and agrees with your aeromods on your own Insight:

Originally Posted by JulianEdgar

My Insight with rear spoiler and fins that measurably reduce lift and drag (fins also provide much better lateral stability):

I cut out the pics that didn't help with the question this all brings up: Given that the stock Insight doesn't match the template and that your fins and spoiler have reduced lift and drag, why don't you apply the template to your Insight with its modifications? Your spoiler does look like it brings the Insight closer to the template.

[JulianEdgar]

This belief in a 'template' (any template) as some kind of help in designed and modifying cars is just very strange. If car aerodynamics were as easy as following a template - any template - then aerodynamic textbooks would be two pages long!

But don't take my word for it. Go and read any mainstream textbook on car aero and see how much space they devote to these 'ideal' shapes - let alone, just one of them!

People here are so lost in the world of templates that they seem to have forgotten reality!

I am sorry you don't have the time to do some testing, because it means your results will almost always be poorer than they could be.

Me? I have this strange belief that in car modification (any car modification), guesswork isn't as good as finding out what actually works.

[sgtlethargic]

Here's the direction I think I'll go instead of doing a cab-all-the-way-forward design. Yeah, it's a toy, but I think you get the idea.

[sgtlethargic]

Originally Posted by JulianEdgar

This belief in a 'template' (any template) as some kind of help in designed and modifying cars is just very strange. If car aerodynamics were as easy as following a template - any template - then aerodynamic textbooks would be two pages long!

But don't take my word for it. Go and read any mainstream textbook on car aero and see how much space they devote to these 'ideal' shapes - let alone, just one of them!

People here are so lost in the world of templates that they seem to have forgotten reality!

I am sorry you don't have the time to do some testing, because it means your results will almost always be poorer than they could be.

Me? I have this strange belief that in car modification (any car modification), guesswork isn't as good as finding out what actually works.

I believe the template is based on information garnered from car aerodynamics books. And, again, you're putting more into the template than what was intended.

[JulianEdgar]

Originally Posted by sgtlethargic

I believe the template is based on information garnered from car aerodynamics books. And, again, you're putting more into the template than what was intended.

I am putting no more into it than I see done here.

And as for "the template is based on information garnered from car aerodynamics books". Well, only insofar as Aerohead took maybe 3 pages out of 500 in a book - and then suddenly made it apparently the most important aspect of car aero!

As I say, go look for yourself - don't take my word for it.

[sgtlethargic]

Originally Posted by JulianEdgar

I am putting no more into it than I see done here.

And as for "the template is based on information garnered from car aerodynamics books". Well, only insofar as Aerohead took maybe 3 pages out of 500 in a book - and then suddenly made it apparently the most important aspect of car aero!

As I say, go look for yourself - don't take my word for it.

I don't know what people here have or have not done that's based on the AST- do you? If someone has ignored the caveats given, then they've misused the information.

And you continue to ignore the point I and others brought up: your approach/delivery. That's after Aerohead said (in this thread) to ~defer to your wisdom~.

[JulianEdgar]

Originally Posted by sgtlethargic

I don't know what people here have or have not done that's based on the AST- do you? If someone has ignored the caveats given, then they've misused the information.

Are you serious?! Apart from grille blockers and wheel covers, basically every aero modification that I have seen people do here has been based on religiously following the template!

And you continue to ignore the point I and others brought up: your approach/delivery. That's after Aerohead said (in this thread) to ~defer to your wisdom~.

Well, clearly I am not much concerned with following your advice in that regard, am I? You're never going to make friends on a forum pointing out how much people have been sucked in by rubbish, or as another poster here puts it, "BS".

[Fat Charlie]

Originally Posted by JulianEdgar

But don't take my word for it. Go and read any mainstream textbook on car aero and see how much space they devote to these 'ideal' shapes - let alone, just one of them!

People here are so lost in the world of templates that they seem to have forgotten reality!

Why shouldn't I take your word for it? You've got the brains and do the work, and your work looks really good.

But I can read. I see your "OMG, the horror, the Insight doesn't meet the template!" I also see "Look at how I improved the Insight." ... by bringing it closer to the template.

Pick one reality. Put your Insight mods against the template. But if you insist on "putting no more into it than I see done here", then post a good profile pic of your Insight so we can. If you won't even do that, leave. Go away. We'll call Darin in to delete all your spammy looking book links.

I'd rather they not be spam, though. Because you do really good work. You improved the first gen Insight, but you're pissed off that other people have also put time into aero work. Can't we all just get along? You're doing great work, why the need to trash other work? Ecomodder is a place to share so that everyone doesn't have to reinvent the wheel. A lot of good work has been done already, and a lot of it has been shared here. You've been adding to that.

Really, though- look at your Insight pic that didn't meet the template, and look at your personal Insight with your own spoiler. It looks like you wanted the Insight to meet the template.