Diagram: How to Ecomod Your Car
 

I can't remember who suggested we should have a visual but here it is.

Feel free to edit it with actual text or something. My writing looks pretty messy.

Also feel free to save it or repost elsewhere. This is for the good of the community!

http://farm8.staticflickr.com/7013/6...84b68a7b_b.jpg

Full Size 11x17 (A3)

Awesome.

great job!!!

you forgot......'gut the interior' :eek: and lose the spare.:thumbup:

i like it

Very nice, Sven. I like the hand lettering, I wouldn't change a thing.

That looks very well done. The hand lettering gives it that casual yet professional look.

Awesome. You forgot "lower it"

Nice job Tyler.

I seem to recall the Kammback on a sedan style car wasn't a guaranteed success, or was it ?

I see no reason why it wouldn't. Maybe vortex formation but that could be dissipated depending how you make it.

This should help reduce vortex formation, by virtue of, well, nearly everything about it is "right" as far as I can tell.
http://i42.tinypic.com/epnj7.jpg
http://ecomodder.com/forum/showthrea...tml#post277037

Referring to this scan which, I think, is out of Hucho, it would change the form from G to a mix between B(a) and F.
http://farm8.staticflickr.com/7017/6...470e94c9_z.jpg

Another option would be a Bonneville style flat spoiler extending horizontally from the trunk. I don't know much about these so here's the theory (maybe someone can chime in and confirm/deny) Much like a truck's tailgate, it would control and take advantage of the tumbling air behind the rear window. This would not be as effective as a Kammback but it would maintain that precious 3 box form so many people love.

PS- I really need to buy a Hucho book. Does anyone have an extra they'd like to part with for considerably less than the $80 used ones on Amazon?

I can't recall it right now and it will take some searching...maybe someone else has it at their finger tips. But, there is an illustration out there that shows the rear transition area and relates it to the radius of this area. It basically showed that the greater the radius of the "Top of the back glass" area, the more aerodynamic it was. Since my Civic has a large radius, I figured that was giving me the best aero performance short of a full Kamm type thing.

So, I think the question of whether a partial Kamm will help or hurt depends on the initial design of the car. Civic..Not so much, 96 Tempo....prolly will help.

Kammback
 

I think Hucho,Jannsen,Emelmann,Buchheim,and a bunch of others were involved with streamlining on the Golf/Rabbit/Jetta/Polo,Quantum,etc..In their drag tables you see that the lowest Cd is achieved when the squareback roofline is relaxed down to the subtle curvature of the K-form.
It's always lower than a notchback.If a notchback is converted to a K-form roof,it can achieve the lower drag.
If even lower drag is desired,just extend the rear further rearward,bringing in the sides as well as Hucho personally oversaw with Jetta.
From there it's just plug and play for lower Cd.

Sven7 -

Fantastic work! I'm gonna make a laminated copy and leave it in my car to show people. You'll get full credit, of course.

CarloSW2

Nice job, Man. I've always been envious of people that can draw well.

Should there be and arrow from the end of the alternator kill switch description pointing to the deep cycle battery instead of the ... , or is it just me?

That is awesome ! :thumbup:

It would be cool if that image would be interactive; as in redirecting to an actual real-life example by clicking on any "green-highlighted" zone. I vote for making it a sticky as some people are way more visual.

Thanks everyone for the comments. I have to admit I traced the Civic to save time, though. Perhaps later on I can make the necessary improvements and mayyyybe even do some sort of interactive document. That would be difficult for me though so if someone is fluent in dreamweaver i might need to ask you a favor ;)

I'm thinking a stop motion GIF would be cool. I could walk around the stock car, stop on a part and photoshop the mod in, then explain it and move on to the next one. Not sure if this would be too large of a file though.

Love the art. Was just yesterday outlining the "lowered cost" approach on vehicles to another, and, if they reply with interest will link to this: See, it isn't as drastic as one might think! A bit here and a bit there . . choose your approach.

Do you mean this one?:

http://ecomodder.com/forum/member-pi...ck-vehicle.jpg

Great idea Tyler! It is a nice visual aid. Thanks for posting this. If you have acces to a video camera perhaps a YouTube link would be a quick way to put this together.

It is a very nice piece of work. Thank you!

...the proverbial "...a PICTURE is worth a 1,000 WORDS..."

Does an alternator kill switch really improve your mpg? All the electricity you draw from your battery has to be put back with a 15% penalty when recharging the battery.

alternator
 

On my CRX,Honda configured the electrical for the field such that at low manifold vacuum( accelerating/climbing,passing) the alternator would drop to 12-V output until the load was reduced,such that at cruise or deceleration,the battery would be topped-off.
A small measure to help out a pretty low-power engine.

So it allows them to downsize an engine more to save fuel. If the technique is added to an existing car it would just be a performance enhancement and not a fuel saver. Correct?

This is great. I'm going to use it tomorrow as a handout at a university event with my students who have been learning the basics of the ecomodding. Your timing is perfect!

Very cool... thanks for creating and posting!!

If only you could teach at my school and perhaps make a difference in future production cars!

A change in production cars would be a great thing to contribute to. But I think there is an opportunity in aftermarket stuff for the existing millions of vehicles too. I talk with students about this and other forms of entrepreneurship that can fill niches and when clever enough and with the luck of the market win changes in how some companies work by effecting their understanding of the opportunities in the market.

True, but I always imagine that in 15 or 20 years the old, inefficient designs will have petered out and we will have pre-aeromodded cars all over. That won't happen if design students don't learn about economy. I'm in my last semester at one of the top two automotive design schools in the country and have not heard more than a passing word about aerodynamics.

There was a student who decided he wanted to put giant wind turbines on the car to charge the battery with wind power while driving on the freeway. I'm not going to name names- he's a good guy- but it just kind of shows the lack of instruction in matters not directly relating to drawing, sculpting and aesthetics. The curriculum is lacking.

I guess what I'm trying to say is I'm very glad you're teaching your students about this and helping to create a grassroots ecomodding aftermarket, but what the world really needs is informed design from the drawing board to the factory.

/rant

Good point but sometimes, yes. Especially if you can charge the deep cycle battery off the grid at night and your commute is short enough to make it home without switching on the alternator. Alternately, (no pun intended) if your route is hilly you can switch it off climbing a hill and switch it on while engine braking on the descent. Modern fuel injected engines use no fuel while in overrun.

OFF while accelerating = less HP and less FUEL needed

ON while decelerating = recharge while coasting.

performance/mpg
 

I reckon that since transient loads are the least efficient,and steady-state the most efficient,that Honda was killing both birds.
When under acceleration,they were removing some load during this least efficient operation to get the car up to operating velocity,then making up the difference on the battery when the engine was near peak BSFC and would suffer a smaller mpg hit.
The same could have been done with the AC compressor employing a normally-closed vacuum switch which goes open circuit upon loss of manifold vacuum.AC is a major hit with a 60-bhp engine.

Nicely said, but the reform of such curriculum is for others (it's not my field). But what I can tell you is that my January course in the histories and cultures of modding cars yielded plans for a new student club focused on modding and scores of stop-bys at my car. Also, my students handed out dozens of copies of your flier, the flier that started this thread. It was very well received. One person picked it up and obviously impressed said "your students made THIS" (a little incredulous). Hahahaha!! I told her no and that a guy from Detroit on ecomodder.com made it. Thanks again...
james

So I guess its only a win to use it when your BSFC drops 15% below your average BSFC.

No, this to me is like showing how the rear window on a Model T might work, almost all modern cars (after 1990) have a radius there at the top of the rear glass, this looks like a study in roof to rear glass with no radius. Could care less about Pinto Aero....

But fer sure thanks a ton for finding this bit here, it just wasn't the thing I remember. The diagram had Radius as the variable, not angle.

Hehe, cool. I'm glad it's well received outside the "cult"!

15%
 

We may want to think of it on a case specific basis.Those with instantaneous mpg readout could monitor mpg behavior with and without 'n see if it showed on the radar screen.

radius
 

In Hucho's book he has eleven graphics depicting Cd as a function of 'sharp' angle roofs.
The last,Fig.4.59 shows optimum angles as a function of length of rear portion of the car.The table shows five different optimum angles for five different lengths.So if you're unfortunate enough to have a roof like this,then you could construct a curve from this scatterplot,and using your own dimensions,find your best angle.
--------------------------------------------------------------------------
Directly following the sharp-edged roof section is Buchheim et al ' work on rounded rooflines.It is this work from which Hucho selects 23-degrees as the maximum recommended slope angle,as is depicted in Fig.4.60.

Yes I agree it would be a case by case basis, however I'm not sure that instantaneous mpg readings are going to tell you when you need to enable it.

Looking at the BSFC chart for my car I can see that enabling the alternator below normal road load (slowing down, braking, going down hill, etc) on the engine would be a loss in efficiency. It has to drop quite a ways to cross the threshold of using 15% more fuel where turning the alternator off would be beneficial. Everywhere else that it is above normal road load has better BSFC or is using less than 15% more fuel.

In my case it would be very difficult to determine where my efficiency dropped below normal enough to justify turning the alternator off would actually help.

threshold
 

Honda's logic was probably to partially deplete the battery on acceleration,then during deceleration,load the field coil and let the alternator do some 'engine-braking',bringing the battery up to full charge,rather than waste all the kinetic energy to hydraulic brake heat.
A thing like this would alter the dyno setting at EPA Mobile Sources certification testing,perhaps giving Honda a tasty MPG number to advertise.