Sam Abuelsamid of Autobloggreen, out in Detroit, had the chance to tour the GM wind tunnel and E-Flex Design studio the othe day and heard from Frank Weber, E-Flex vehicle line executive.
Sam has written a post about it: (LINK)
He talks about why aerodynamics are so important in this car, more so than mass.
He also goes through a bit of the styling changes that have to and are taking place.
Well worth a read. Thanks Sam.
This entry was posted on Wednesday, December 12th, 2007 at 10:58 am and is filed under Design, E-Flex, Efficiency, Engineering. You can follow any responses to this entry through the RSS 2.0 feed. Both comments and pings are currently closed.
Dec 12th, 2007 (11:15 am)“We were also shown a one-third scale model in the wind tunnel that was covered in duct tape to obscure details.”
Heh. Photo-ops are funny sometimes.
Dec 12th, 2007 (11:26 am)Thanks, Lyle! The article you supply a link to above provides a few more styling cues, viz: “Clearly the front of the Volt had to change. Looking at the car in plan view (the view looking down from above), the concept was almost flat across. Not good. A more parabolic shape was needed to allow air to flow smoothly around the sides of the car without separating from the body (which causes turbulence). The headlights are now flush with the body rather than being set back as they are on the concept (as you can see in the gallery below). The main twin port grille is blocked off and engine compartment airflow comes from below the bumper. The car will have a full belly pan to manage airflow under the car…
…The line from the roof to the rear deck is much like the concept. The base of the windshield has moved forward providing more rake to the glass. It appears the center line of the front axle has moved back a bit allowing for more front overhang while the front corners are swept back to provide better airflow as well as helping to meet European pedestrian safety standards. The other main visual difference that was apparent from hints around the studio was a reduction of the Coke bottle effect along the sides. While the concept had prominently flared fenders, this will be toned down significantly to help keep the airflow attached to the sides. One other design element that will be prominently maintained on the sides is the plug ports since this is such an important part of what this car is all about.”
Note that, as suggested by the previous “teaser photo” from a few days ago, “the main twin port grille is blocked off and engine compartment airflow comes from below the bumper”. I just hope GM finds an eye-pleasing way to do this other than by use of ugly, plain panels as in the teaser photo!
Dec 12th, 2007 (11:39 am)Clarification: It’s the video from a day or so ago, in which a guy pulls back a blue tarp to show the front corner & part of the grill, where the ugly plain flat panels are shown blocking the twin ports of the grill.
YUUK!!!
Dec 12th, 2007 (11:50 am)It’s all good.
The discussion of the relative influence of mass and airflow on range is really thought provoking.
In the midst of this Holiday season, I have gotten to thinking about how lucky General Motors is to have such a dedicated cadre of bloggers who are so passionately interested in its future success and viabiliity.
Whether I personally agree with people or not, all of the discussion and back and forth clearly serves to illuminate the issues and keep them up on the radar screens.
A wise political operator once told me that, for every person who will take the time to write a letter or make a phone call, there are 200 who feel the same but won’t take the trouble. My experience is that the multiplier is probably even higher than that. I think that the same goes for blogs. I think that GM realizes that, or at least they had better.
So, starting with our leader Lyle, happiest of Holidays to each and every one of you, and the most successful and prosperous of New Years. May we all be diriving Volts and doing our bit for energy independence and the environment as soon as possible.
Dec 12th, 2007 (12:03 pm)If GM is serious about real aerodynamic styling for the Volt, the 2010 version will look nothing like the concept version that we have now.
Dec 12th, 2007 (12:04 pm)I’d take a flat panel grille if I knew that it retracted when the ICE kicked on. That would make it cool.
Dec 12th, 2007 (12:19 pm)Jim G, #6:
Good idea!
Kind of like high tech Nascar tape on the grille!
Dec 12th, 2007 (12:43 pm)Noel #4:
“In the midst of this Holiday season, I have gotten to thinking about how lucky General Motors is to have such a dedicated cadre of bloggers who are so passionately interested in its future success and viabiliity.”
‘Tis very true. I just got done reading The Tipping Point on a recent flight. It explained in detail how epidemics (diseases, product growth, etc) start and are spread. Epidemics are initially spread by a surprisingly few number of people. These are the Connectors, the Mavens, and the Salesmen.
Connectors are people who know everyone. They are seen as “cool” with an ability to be culturally contrarian and set new trends. They are sociable personalities who bring many disparate people together. An example is a bunch of teens in East Village, New York who started wearing seemingly old fashioned Hush Puppy shoes, and subsequently the product sales mushroomed. Because these fashionable types started wearing the shoes, they gave “permission” for society at large to start buying them in droves.
Mavens are people who like to pass along knowledge and give advice. They are very knowledgeable in a specific area and enjoy sharing it. Their advice is respected and sought after and are profoundly influential in the critical mass phase of a product launch, despite their small numbers. An example is the individual who started camcorderinfo.com. Other examples are Sam of autobloggreen.com and Lyle of gm-volt.com.
Dec 12th, 2007 (1:43 pm)Very informative and impressive post. Thank you Lyle and everyone who made it possible. You can almost feel the car coming together.
Dec 12th, 2007 (4:46 pm)I guess our hopes of seeing something new at the Detroit Auto Show have been squashed…
I would really like to see where they are with the interior and exterior design.
Maybe if we get enough teaser shots, we can put them all together in photoshop and make our own teaser!!!
And I echo the “Happy Holidays To All” comments. I may disagree with some of you completely, but I still wish everyone a healthy, safe, happy and prosperous new year!
Dec 12th, 2007 (5:45 pm)Happy Holidays from me too…
I bought LED light strands this year to replace the conventional ones. They are a bit pricey ($9.99 for a 60-light strand at CVS vs. $3.99 for a 100 light strand of the conventional ones) but they use up to 90% less electricity!
Dec 12th, 2007 (6:03 pm)Hey GM! Regarding the Volt’s front end styling vs aerodynamics, why not let your own ’08 Corvette front end design inspire a new approach? As with the ‘Vette, eliminate a conventional grill and slope the hood downward dramatically to a “snoop”. The slope of the Volt’s less-crammed hood could be even more severe than the ‘Vette’s and its snoop could be as wide but even lower. This snoop should allow you to easily conceal 1) air vents into the Volt’s ICE/generator/motor area, 2) an all-important air dam and 3) an air deflector to steer air below the car’s under belly panels by blackening out these recessed surfaces. The proportions of these 3 aerodynamic components could then be easily adjusted to achieve the lowest possible drag without affecting the styling.
Then, for icing on the cake, eliminate ALL emblems except for a large flat gold lighting bolt on the hood for a little intrigue/pizzazz! (My 1982 Z-28 had NO BowTie or Chevy/Chevrolet emblems on it either inside or out –and I got LOTS of interested inquiries at the car wash!) This approach to the Volt’s front-end styling should say, “GM is getting serious about an “E-REV-OLUTION”!!!
Dec 12th, 2007 (6:08 pm)It looks like Tesla is considering a range extended EV design for their next gen Whitestar sedan.
http://www.teslamotorsclub.com/showthread.php?p=4459
Isn’t competition great.
Dec 12th, 2007 (6:13 pm)Hey GM! Regarding the Volt’s front end styling vs aerodynamics, why not let your own ’08 Corvette front end design inspire a new approach? As with the ‘Vette, eliminate a conventional grill and slope the hood downward dramatically to a “snoop”. The slope of the Volt’s less-crammed hood could be even more severe than the ‘Vette’s and its snoop could be as wide but even lower. This snoop should allow you to easily conceal 1) air vents into the Volt’s ICE/generator/motor area, 2) an all-important air dam and 3) an air deflector to steer air below the car’s under belly panels by blackening out these recessed surfaces. The proportions of these 3 aerodynamic components could then be easily adjusted to achieve the lowest possible drag without affecting the styling…..
Dec 12th, 2007 (6:21 pm)Base post: “He talks about why aerodynamics are so important in this car…”
If gas hadn’t been so cheap for so long we’d learn aerodynamics (reducing drag) is important for any vehicle designed to drive highway speeds. With everything else being equal, less drag, better MPG. Personally I won’t care how it looks, though I realize the mass market does so there’s going to be a trade off.
Brian M, consider it an investment as it’s possible your LED strands will also last many (possibly 10) times longer without a buld burning out.
I don’t believe I’ve read yet whether or not the Volt will use LED exterior lights (including the headlights) to extend range? I think the Tesla is but they aren’t trying to sell it for under $30k
Dec 12th, 2007 (6:30 pm)As a followup to my #13 above, review that suggestion while you take a look at:
http://www.motortrend.com/roadtests/coupes/112_0708_2008_chevrolet_corvette/photo_01.html
Then, for icing on the cake, eliminate ALL emblems except for a large flat gold lighting bolt on the hood for a little intrigue and a lot of pizzazz! Hey, my 1982 Z-28 had NO BowTie or Chevy emblems on it either inside or out –- and I got LOTS of interested inquiries at the car wash! This approach to the Volt’s front-end styling should say, “GM’s getting serious about an “E-REV-OLUTION”!!!
Dec 12th, 2007 (6:46 pm)OhmExcited, does make you wonder when Ford is going to announce one given they also were talking about one in their 2003 slide show on the EPA website, ie. http://www.epa.gov/oar/caaac/mstrs/ford.pdf (pages 6 and 7)
As far as I can tell it was GM who was the 1st big auto company at least thinking about one in the 2001 article http://www.autoworld.com/news/GMC/Series_Hybrid.htm (this one an EV-1 with a range extender). So it’s only fitting GM be the 1st going to production.
Dec 12th, 2007 (8:03 pm)[quote comment="19164"]Connectors are people who know everyone. They are seen as “cool” with an ability to be culturally contrarian and set new trends. They are sociable personalities who bring many disparate people together. An example is a bunch of teens in East Village, New York who started wearing seemingly old fashioned Hush Puppy shoes, and subsequently the product sales mushroomed. Because these fashionable types started wearing the shoes, they gave “permission” for society at large to start buying them in droves.[/quote]
I was a ‘connector’ responsible for numerous fads and trends.
Do you remember back in the 70′s when everybody was walkling around with ‘boom boxes’ on their shoulders? I started that, I was one of first people to walk around with a ‘boom box’ on my shoulder.
How about parachute pants, anyone remember those?
I started the parachute pant craze, and get this, I did’nt even wear them!
And finally, before me cats and dogs got along just fine; it was I who turned cats and dogs against each other.
Dec 12th, 2007 (9:06 pm)[quote comment="19223"]It looks like Tesla is considering a range extended EV design for their next gen Whitestar sedan.
http://www.teslamotorsclub.com/showthread.php?p=4459
Isn’t competition great.[/quote]You almost certainly won’t be able to get it for the price of the Volt.
Dec 12th, 2007 (9:07 pm)[quote comment="19224"]Hey GM! Regarding the Volt’s front end styling vs aerodynamics, why not let your own ’08 Corvette front end design inspire a new approach? As with the ‘Vette, eliminate a conventional grill and slope the hood downward dramatically to a “snoop”. The slope of the Volt’s less-crammed hood could be even more severe than the ‘Vette’s and its snoop could be as wide but even lower. This snoop should allow you to easily conceal 1) air vents into the Volt’s ICE/generator/motor area, 2) an all-important air dam and 3) an air deflector to steer air below the car’s under belly panels by blackening out these recessed surfaces. The proportions of these 3 aerodynamic components could then be easily adjusted to achieve the lowest possible drag without affecting the styling…..[/quote]
Have you ever seen the length of the Corvette’s hood?
This car has to seat 4 people as comfortably as a normal car you know.
Dec 12th, 2007 (9:16 pm)FYI, the wait list number isn’t showing up on IE6 but shows up fine on Firefox at work. Odd…
Dec 12th, 2007 (10:24 pm)Saying that areo is more important for this car than others is kind of dumb. (Also, people are forgetting the word ‘relatively.’) The justification is that additional mass would be used for more battery capacity which isn’t necessarily true. I’m sure that improving aero by a certain amount would help a similar gas car just as much and I’m sure that reducing the amount of steel in the Volt would help it just as much too.
Dec 12th, 2007 (11:21 pm)In the video in the link, it was certainly great to hear that the A123 battery pack has been delivered to GM for testing. It will be interesting to find out how it performs.
Dec 12th, 2007 (11:39 pm)I just thought of something (off topic)…
How do you turbo charge a 3 cylinder engine?
With a 4 or 8 cylinder engine there’s always at lest 1 piston on the intake stroke. But with a 3 cylinder engine I don’t see how that’s possible. So if the turbo is spinning with inertia, it will be pumping air all the time even when there’s no intake valve open. So will the wastegate on the turbo flap open once every main crank RPM?
Any mechanical wizards out there?
death to oil
http://www.oiljihad.org
Dec 12th, 2007 (11:52 pm)Vernon-Ga-Tech #23:
I believe A123 has sent the batteries to their partner, Continental, for packaging. I have not heard GM has received them yet. I have read GM will receive them towards the end of this month or beginning of January. Has anyone heard or read otherwise? This would be another big milestone.
Dec 12th, 2007 (11:52 pm)[quote comment="19273"][quote comment="19224"]Hey GM! Regarding the Volt’s front end styling vs aerodynamics, why not let your own ’08 Corvette front end design inspire a new approach? As with the ‘Vette, eliminate a conventional grill and slope the hood downward dramatically to a “snoop”. The slope of the Volt’s less-crammed hood could be even more severe than the ‘Vette’s and its snoop could be as wide but even lower. This snoop should allow you to easily conceal 1) air vents into the Volt’s ICE/generator/motor area, 2) an all-important air dam and 3) an air deflector to steer air below the car’s under belly panels by blackening out these recessed surfaces. The proportions of these 3 aerodynamic components could then be easily adjusted to achieve the lowest possible drag without affecting the styling…..[/quote]
Have you ever seen the length of the Corvette’s hood?
This car has to seat 4 people as comfortably as a normal car you know.[/quote]Point taken, James. But note that the ’08 Corvette also has a much longer REAR overhang than the Volt concept, enough to allow for the extra 20″ or so needed for the Volt’s 2 rear seats.
But my REAL point is that the traditional grill on the Volt concept could be replaced with a steeply-sloping smooth hood that eliminates the grill, and instead tapers to a low & wide “snoop” as on a late-model Corvette or Ferrari. This is a way of achieving BOTH highly-distinctive styling AND a very low drag coefficient, and it should be feasible since the Volt’s 3-cyl ICE + generator + 160HP electric motor are MUCH smaller and dissipate much less heat than a Corvette’s big V-8 or a Ferarri’s V-12.
Dec 13th, 2007 (12:00 am)….again, here’s the ’08 Corvette to illustrate how a steeply-slooping hood with no separate grill and a low-wide “snoop” looks:
http://www.motortrend.com/roadtests/coupes/112_0708_2008_chevrolet_corvette/photo_01.html
Dec 13th, 2007 (12:11 am)The Chevrolet Sprint / Geo Metro had a 1.0L 3 cylinder turbocharged engine. Just google to read all about it. I hope to God they have improved it since then.
Dec 13th, 2007 (12:47 am)With regards to the Corvette front-end suggestion… The long hood sloping down to a wedge-like nose is one way to improve leading-edge aerodynamics, but probably not the best approach for a compact car like the Volt.
The better approach for this kind of car is to have the windshield slope smoothly into a short hood and a blunt (but smooth) nose. In other words, less like the Corvette, more like the new Civic body.
The combination of a long hood and blunt nose in the concept body is a big aero mistake. Long hoods go with wedge-like noses, blunt noses go with short hoods and sloped windshields.
From the side-view, the profile should minimize or eliminate the harsh angle between the hood and the windshield as well as that between the rear window and the tail. If the curve from the top of the canopy to the top of the front wheel wells is smooth, then the nose can be compact and blunt.
Dec 13th, 2007 (1:20 am)OhmExcited, regarding the Geo Metro. I remember one of my friends after college buying one of those in the Summer of 1986.
It got over 50 miles per gallon, sat 5, and did a good on the highway (had no problem merging with traffic, etc, even if it couldn’t go 0-60mph in 4 seconds).
Could have given the Prius a run for the money. Just amazing that congress may soon be patting themselves on the back for upping the CAFE numbers to 35mpg by 2020, almost 35 years after the Metro got 50mpg.
Dec 13th, 2007 (1:27 am)Jihadi,
On aircraft I have worked on, the wastegate is controlled by an actuator which is operated by the incoming pressure into the intake manifold. It moves in a smooth fluid motion, so it doesn’t “flutter”.
So the number of cylinders is irrelevant to it’s operation, just intake pressure.
Death to oil.
Dec 13th, 2007 (2:06 am)guy, you still whining on here? i swear you’re doug k. incognito.
Dec 13th, 2007 (2:49 am)[quote comment="19300"] Long hoods go with wedge-like noses, blunt noses go with short hoods and sloped windshields.
[/quote]
It looks like they’ve chosen the long hood and wedge-like nose approach. The long hood was part of what really defined the concept to me.
Long hood will be better for mounting the two engines underneath, anyway.
[quote comment="19300"] the profile should minimize or eliminate the harsh angle between the hood and the windshield as well as that between the rear window and the tail.[/quote]
Sam’s comment of “The base of the windshield has moved forward providing more rake to the glass” seems to have addressed the front angle problem.
Also, if you look at this picture:
http://futuredrive.files.wordpress.com/2007/12/picture-8.png
There’s a sketch on the whiteboard that seems to show a much smoother angle at the rear.
Dec 13th, 2007 (10:38 am)I agree, AES, that a long sloped hood makes lots of sense both aerodynamically and in terms of styling distinctiveness ….given the small volume needed by the Volt’s under-hood components it should be feasible. And I’d LOVE the look of a big, flat, gold lightning bolt on that hood (where the Corvette winged emblem is on its long smooth hood, and instead of the Chevy Bow Tie)!
Dec 13th, 2007 (11:00 am)“Saying that areo is more important for this car than others is kind of dumb.”
Here is what the article said:
“Driver behavior is clearly a factor for both traditional and electric cars. Beyond that, on traditional cars, factors like mass, aero drag and rolling resistance come into play in that order. In testing and simulation GM has found that for electrically-driven vehicles mass actually drops to third on the list behind aerodynamics and electrical loads with rolling resistance coming in fourth.”
Do you dispute this?
Dec 13th, 2007 (11:46 am)[quote comment="19370"]“Saying that areo is more important for this car than others is kind of dumb.”
Here is what the article said:
“Driver behavior is clearly a factor for both traditional and electric cars. Beyond that, on traditional cars, factors like mass, aero drag and rolling resistance come into play in that order. In testing and simulation GM has found that for electrically-driven vehicles mass actually drops to third on the list behind aerodynamics and electrical loads with rolling resistance coming in fourth.”
Do you dispute this?[/quote]Mike756, from GM’s comment that you quote above (last sentence) they’re ranking for an EV is: 1) aerodynamics, 2) electrical loads, 3) mass & 4) rolling resistance. My guess is that they’re weighing aero highest because of the fact the drag at 35 MPH (around town) will be only about 1/4th the drag at 70MPH (on the Interstate). Since the average buyer will focus primarily on the Volt’s non-extended ELECTRICAL range, which will deteriorate much faster than a conventional car’s range at 70MPH, aerodynamics indeed becomes a VERY important parameter!
Dec 13th, 2007 (12:37 pm)nasaman
I agree, thats why I was very surpised by the previous article that said that aerodynamics accounted for only 20% of the energy.
Oct 22nd, 2009 (8:22 pm)Both of these examples illustrate how librarians are not just adding new software but tweaking it to improve the experience for their users. ,