In the latest installment of GM-produced two minute transparency videos, the company gives us a taste of what its like to test the Chevrolet Volt braking system.
Featured in the video is Performance Integration Engineer Valarie Boatman who describes how GM tests braking, stability, and traction control in Volt prototypes.
She notes that the stopping time test is very important and is measured as a pass or fail. The Volt’s brakes she says “are phenomenal,” and they are much faster than the brakes in a conventional car. This is because the Volt’s brakes use an accumulator which is more responsive and rapid than conventional vacuum-boost brakes.
Also measured is the ability to steer while braking and brake while steering. In this test, she measures the car’s yaw rate or rotational behavior, which is also measured on a pass fail basis.
For stability control the car’s tendency to spin out of control is measured, and engineered to be kept at a minimum.
Traction control is measured by seeing how fast the car can accelerate without spinning the wheels too much.
On all counts the Volt delivers.
She notes the testing process just for the brakes ” takes months and months” of eight to ten hour workdays, just to get things right. In the end though she finds working on the Volt “is a really cool opportunity.”
See video below:
This entry was posted on Friday, July 23rd, 2010 at 6:19 am and is filed under Performance, Safety. You can follow any responses to this entry through the RSS 2.0 feed. Both comments and pings are currently closed.
Jul 23rd, 2010 (6:22 am)Impressive video!
+3
Jul 23rd, 2010 (6:30 am)PS to my post #1: I’m wondering whether the Volt has stability and/or tracking controls —scrutinizing the console buttons, I can’t see any (unless “AS1-2″ could mean “automatic stability” control (1 or 2)??? My ’08 VUE has both traction & stability switches on the dash, so I would expect the Volt to also have switches. Does anyone know?
+3
Jul 23rd, 2010 (6:30 am)Also measured is the ability to steer while braking and brake while steering.
–
Are these different? No matter, still important and impressive.
+1
Jul 23rd, 2010 (6:41 am)Lyle, your judgement is impeccible. Very nice counter to the Jay Leno remarks. This is one facet of why the Volt really attracts me.
BTW, how the Volt handles rough road would be a nice article. The roads in Michigan are horrible.
+1
Jul 23rd, 2010 (6:48 am)Now I know what I want to do when I grow up
(and when does that Voltec Camaro come out?)
Jul 23rd, 2010 (6:51 am)Actually, some clarification about handling on rough roads: “my” last car was a 2001 Chrysler Caravan. Our place of work moved to downtown Detroit. The commute from the suburbs to downtown was actually quite pleasant until the major construction on I75 began. The detours and work-arounds just pounded the suspension of the minivan. After about 6 months of that it never felt tight or smooth again.
So, if I put money into the Volt (when, not if) I want to know if it can take it, or do I have to take extra time to avoid the pounding, punishing treatment that our roads dish up?
Jul 23rd, 2010 (6:54 am)“Chevrolet Volt braking system”
Tomorrow’s story….. CS mpg revealed!!!
GO EV!!!
+3
Jul 23rd, 2010 (6:56 am)It’s great to watch the car evolve into production. I don’t think there’s ever been a car that has been so closely watched and every step scrutinized through development by potential buyers.
That said, I’m surprised the video didn’t mention the regenerative braking and it’s relationship to the actual brakes at all.
+4
Jul 23rd, 2010 (6:57 am)Sometimes you wonder how it could cost a billion dollars for development of the Volt.
When you see videos like this one, and many of the others available, it starts to make sense.
And it is the reason I want a car like this from a major manufacturer. They know how to design, and test, re-design and re-test, until it is right!
Go GM!!! Go GM Volt Team!!!
NPNS
Have Outlet – Ready For E-REV – Hopefully in 2012 in Youngstown, Ohio!!!!!
+5
Jul 23rd, 2010 (7:02 am)It was so cool to see the Volt racing around a track at normal/high speeds. I’ve seen way to many videos of the Volt going 20mph in a coned out parking lot. I would love to see a race car driver get behind the wheel and get his impressions since the weight distribution is so different in this car. What does he think of the brakes? What about that steering response?
I want this car to be so good that it will get compared to any car in it’s price class. I think it will be more attractive to the masses if we all can forget about the electric and hybrid rivals and think of it as the first NEW NORMAL car. A car for the mainstream man.
Jul 23rd, 2010 (7:04 am)I’m thinking Volt’s acceleration should be wonderful, with use of traction control and Sport mode selected. Can’t wait to drive one with just me in it.
+1
Jul 23rd, 2010 (7:26 am)That is an impressive video. It also explains the cost and time associated with the production of a vehichle such as this. Is this much time and effort put in to every car on the road today?
+1
Jul 23rd, 2010 (7:36 am)I truly enjoy seeing these “finishing touches” videos and articles. It builds anticipation to what will be an amazing vehicle.
ICGMSE
(I can’t get mine soon enough)
+1
Jul 23rd, 2010 (7:36 am)“The brake system uses an accumulator…” for faster pedal to wheel response over a conventional hydraulic boost system.
In addition to balancing it in with the regen braking. Two exclusive systems. The brakes themselves are notable for how normal they are, not like having a grabbing hybrid car feel.
In what other vehicles does GM us an accumulator? I haven’t kept up with brake systems much beyond abs and yaw control.
To me, this addition to the Volt is another example of how GM is creating an enjoyable car first.
The Volt is raising the bar considerably in quite a few areas of hybrid and electric car development.
+1
Jul 23rd, 2010 (7:44 am)Valarie is a motorcycle racer, somewhat similar. (And a horseback rider, BTW.)
Jul 23rd, 2010 (7:57 am)TRACTION CONTROL is a BIG DEAL!
I posted the info below a few days ago when this video came out. The question I posed below was answered by another poster stating there is an OPTION to allow the driver manage traction control in some conditions when needed.
As others have already noted GM is doing a great job testing and validating the quality of the VOLT.
***
“Just saw a You Tube video about the VOLT braking system testing at the Milford proving grounds ( from the Chevy Volt web site – Facebook)
The Ms. Boatman noted traction and stability controls on the VOLT.
This brings a question I have had about the VOLT… actually a safety issue….
**Can the “traction control” be “turned off” so if one has to go up a hill in a winter snow covered driveway w/o the car stopping because of slippage? Winter driver sometimes requires the need for the driver to manage the wheel slip, not the car.
Sad example in my Prius .. when I tried to keep going up a snow covered hill to leave my drive the Prius keep “putting on the brakes.” The car stops and slides backwards. NOT A SAFE Option.
Does anyone know about the traction/stability control options on the VOLT in this area??? :+} ”
***
+2
Jul 23rd, 2010 (8:00 am)I’m guessing that the difference is in what activity you’re doing first. If you’re braking and then you steer, that may behave differently than if you’re steering, and then you brake.
Very cool video.
join thE REVolution
+1
Jul 23rd, 2010 (8:14 am)Just a quick question Valarie – when can we get married?
Jul 23rd, 2010 (8:17 am)Lets hope that Valarie is about done with all her testing, since “months and months” would mean not completing the testing until near the golden Nov date.
BTW: How does GM find all these hot women that really seem to know what they are doing? I want to work at GM!
+1
Jul 23rd, 2010 (8:18 am)Very good on the part I underlined. Quite a few cars have been too aggressive on the limiting of the wheel spin. This makes them useless in snow, mud or even deep loose gravel. On surfaces where there is loose material, the wheels have to spin faster than the vehicle to keep the car going. If the traction control won’t let the wheels over-spin the car speed at all, they will just come to a stop and refuse to move.
One car that got this wrong is the Ford Fusion all wheel drive. It’s a freaking all wheel drive car than can be stopped by snow because they won’t let the wheels spin up.
Jul 23rd, 2010 (8:20 am)One of the colors for the Volt is White Diamond Tri-Coat. Does this stand up to sand blasting better than standard white? And the other colors?
=D-Volt
The silver exterior with an emerald hue will be available exclusively on the Chevy Volt. The new, consumer-named paint will join a palette of other Volt exterior colors available to order at the start of production including Black, Silver Ice Metallic, Cyber Gray Metallic, Crystal Red Metallic and a premium White Diamond Tri-Coat.
Jul 23rd, 2010 (8:21 am)Glad to know that I’m not the only pig that notices….
I never figured Detroit would be the place to run into cute women engineers. I guess that’s why I haven’t run into them, they’re all working at GM.
Jul 23rd, 2010 (8:22 am)Never had that happen with the 2004. I upgraded to better tires. With the 2010, the system has been improved so much that even basic factory tires work fine.
Question is, what kind of tires will Volt come with? With weight well above average for that size vehicle, they are likely XL grade.
+1
Jul 23rd, 2010 (8:22 am)A LITTLE OF TOPIC:
http://finance.yahoo.com/news/GM-plans-to-file-for-IPO-rb-2838083425.html?x=0&sec=topStories&pos=7&asset=&ccode=
I guess Right before or right after we should get VOLT pricing
NEW YORK/DETROIT (Reuters) – General Motors Co (GM.UL) plans to file its registration for an initial public offering during the week of August 16, just after the expected date for its second quarter results, according to two people with direct knowledge of the preparations……
+6
Jul 23rd, 2010 (8:38 am)I had to ask… Lyle can we have a vote on the HOTTEST engineering women at GM?!
+1 for Valarie Boatman
I know I know, but she is a cutie. Anyone else with me
Jul 23rd, 2010 (8:40 am)I have had several people tell me that they experience this same issue. When you try to drive up a snow covered hill, that the wheels will actually lock, and you will not be able to move. When driving in snow, you need to allow the wheels to spin to allow you to move/control the vehicle. I know Honda has the same issue on the Accord and I think the Oddesey.
Jul 23rd, 2010 (8:43 am)When you steer first the car will tend to understeer (slide the front wheels once traction limits are exceeded). If you hit the brakes when already turning, the understeer increases because the front wheels already have a side load and braking can break the tires loose.
When you brake and then steer the care is more prone to oversteer (slide the back end around). Braking moves the weight forward which increases the front traction and reduces the rear traction. It give the ability for the car to yaw faster which then can cause it to spin out.
Most new (except high performance) cars then to understeer because it is deemed “safer.” When driven by sheeple, it probably is. An oversteering car can go around corners faster but the driver has to be careful to not spin out.
Jul 23rd, 2010 (8:46 am)Probably right. If the Volt’s price is lower than we expect then they’ll probably announce before. If we don’t get the price until after, then I would expect it to be closer to 40k then we are all hoping.
Jul 23rd, 2010 (8:48 am)Look at post 16. The 2006 Prius has the same disastrous issue. Sad to read the Ford Fusion has it too.
LET US HOPE THE VOLT HAS AN OPTION TO CONTROL THIS PROBLEM.
Could GM verify this once and for all?
Otherwise it could be a deal killer for some in snow states.
+1
Jul 23rd, 2010 (8:50 am)The fact that the Volt would spin out in the video is a good sign. In many new cars they won’t spin at all and this makes them useless in the snow, mud or even deep gravel.
I detected a bit of a souther twang in Valarie, so I bet that helps
“Of course it should be able to burn out, it’s not some prissi car”
PS: Your Prius is PERFECT. Toyota NEVER makes any mistakes. Many other cars on the road may have the same issue, but certainly not the Prius. The only possible defect is the driver. Don’t believe me? Some fanboy troll will be along to tell you so….
Jul 23rd, 2010 (8:56 am)They hire a lot of the female co-ops from Kettering University. (note: Valarie is an exception from Texas)
Jul 23rd, 2010 (8:57 am)We have crossing posts
I think the Volt is good to go without the switch simply because it spun out in the gravel. The cars with the problem won’t spin out at all.
Ford has fixed it in the new Fusion. They didn’t add a switch, but added more firmware that identifies that you are indeed on a loose material surface and changes the traction control. The car then locks up the differentials tight and lets you spin out all four wheels together.
+1
Jul 23rd, 2010 (8:57 am)The wheels don’t lock if you drop the pedal to the floor. Most owners are afraid to try that. They don’t realize it informs the system to pulse. Tire power will automatically alter from one to the other. It’s a type of rocking feature many owners are totally unaware of.
The 2010 model has a rare feature like that too, hill assist. It simply doesn’t cross an owner’s mind that pressing really hard on the brake pedal while on an incline will temporarily lock the brakes, allowing you to shift your foot over to the accelerator pedal without any rollback.
+7
Jul 23rd, 2010 (9:01 am)Another example of why the ‘performance’ of the VOLT should be compared to a BMW 3-series instead of a Prius. In fact, that should be the comparison test that MotorTrend or Road and Track does. Is it more like the Beemer or the Toyota?
+1
Jul 23rd, 2010 (9:01 am)I did get “better traction tires” it did help some BUT the rolling resistance was higher and I lost about 2 to 3 miles a gallon…… so the trade off. The new tires were 90k miles rated while the OEM tires as most Prius owners know are 40k miles.
I have been reading tires are improving in traction while maintaing lower rolling resistance. It would work for me.
But the better option would be a way to turn off traction control, when needed, on all cars.
Jul 23rd, 2010 (9:04 am)Friday July 23, 2010, 5:41 am EDT
GM plans to file for IPO during week of August 16
http://finance.yahoo.com/news/GM-plans-to-file-for-IPO-rb-2838083425.html?x=0&sec=topStories&pos=7&asset=&ccode=
=D-Volt
Jul 23rd, 2010 (9:05 am)Nissan ought to take notes. As far as I know, nobody knows if they are doing the same kind of testing as GM is doing with the Volt. I guess they are banking on trust.
Too bad for them. Seeing the dowdy looking LEAF being hammered like we’ve seen happen to the Volt would help shake off its fruityness and give it a bit more of a manly, solid image.
+2
Jul 23rd, 2010 (9:05 am)I, too find it impressive that women are well represented at GM. I forget all their names, but the women we have seen in all the GM Volt videos and web conference calls can be genuine role models for getting more girls interested in engineering and science. GM should be proud.
As far as stating that, “How does GM find all these hot women that really seem to know what they are doing?” you could have stated that better, but we get your meaning.
+1
Jul 23rd, 2010 (9:07 am)I trust you on that.
So, does Toyota or other manuf. instruct people on how to perform this maneuver, or do you they just assume you will figure it out. I really have little experience with AB systems, and my car does not have ABS, but I do have 30+ years of driving in snow. It would be extremely frustrating to own a newer car, and find that you could not get up your driveway, but your 15 year old car climbs right up.
I am not a big fan of ABS, but for my wife I would prefer it. I am of the opinion that, a person who understands how to brake/steer can actually out perform and out maneuver an ABS outfitted vehicle.
This whole ABS subject, brings me back around to issues with adding complexity to vehicles. While, I understand that some things can be improved upon and made more reliable with complexity, adding complexity does not always translate to better and more reliable vehicles. I still remember when Honda used to advertise “We make it simple”, and then they got bashed around by other car makers, saying Honda was simple. I like the idea of “We make it simple”, and believe that if car makers concentrated more on making the simple things better, instead of adding more gadgets and gizzmos to its cars, that it would be a much better car. So, relative to the Volt, I would contend that the ICE makes the Volt more complex, and more unreliable, in the sense that the ICE does not add any additional capability, but only provides a redundant drivee system.
Jul 23rd, 2010 (9:10 am)It might just be automatic and always on.
+3
Jul 23rd, 2010 (9:16 am)Speaking of hot women….
Recently while driving an a Chicago expressway I spot this big billboard sign that says in large letters: YOUR WIFE IS HOT!!!
Underneath in small letters it says “get her a central air conditioner from (can’t remenber the company name).
I hate billboard advertising but thought this one was clever and funny.
+1
Jul 23rd, 2010 (9:19 am)There’s no way I could pump my brakes in the snow as fast as my ABS does.
-1
Jul 23rd, 2010 (9:20 am)Why do we talk about GM’s “transparency,” when they don’t reveal the CS mileage or price?
They didn’t even post stats from their heavily hyped “Freedom Drive.” Why didn’t GM publicize their own publicity stunt?
+1
Jul 23rd, 2010 (9:21 am)BLDude,
Agreed. I should have said “who know what they are doing”, instead of “seem to know what they are doing”.
The coolest part, is that Valarie is the person actually driving the Volt during the testing. My first thought was that she was just taking all the measurements/data and was more of a mouthpiece, but then I saw her actually ripping around the track. Way Cool!
Now, if that would have been a guy, I would have probably thought that he was doing it all. I guess my male chauvinistic side was showing…
-1
Jul 23rd, 2010 (9:23 am)KDawg,
I 100% agree that I could not pump the brakes that fast either, but sometimes when you are in an emergency manuever, you want to actually be able to temporarily lock your brakes, then steer out of the situation. The ABS would prevent this.
+1
Jul 23rd, 2010 (9:29 am)Because they chose not to.
Jul 23rd, 2010 (9:42 am)That’s what I was thinking.
-6
Jul 23rd, 2010 (9:43 am)Would you care for some more Kool-Aid, JEC?
Jul 23rd, 2010 (9:43 am)My early ’90s Saturn SW2 wagon (the small one) had all-speed traction control that worked by managing the engine torque (via spark timing) and transmission gear. Since it didn’t involve the brakes, it never locked up the wheels in poor traction conditions. Cool side effect is that it would flash the TC indicator light whenever the tires started to hydroplane. That saved me from drama on a number of occasions.
With the electric drive motor, I’d be pleasantly surprised if the Volt’s traction control also worked, at least in part, by torque management.
Regarding the tire question, the Volt’s tires have already been announced somewhere around here. Specific, low rolling resistance.
CorvetteGuy: Interesting suggestion to comparison-test the Volt against the similarly sized/priced BMW 3-series. Point of snotty nomenclature: “beemer” is a BMW motorcycle. “Bimmer” is a BMW car. Yeah, it only matters to those utterly steeped in the lore of the kidney grill.
+1
Jul 23rd, 2010 (9:53 am)Oh, Yeahhhhhhhhhhhhhh!
Thanks!
http://www.youtube.com/watch?v=nBeUGqeYsQg
Jul 23rd, 2010 (9:58 am)You may be right, Steve. However, I’ll further guess that the Volt might default to AS-1 (a milder version?), but that pressing the AS1-2 nib once on the console enables AS-2 (a more aggressive version?) and pressing the same nib again temporarily disables BOTH stability control and traction control to allow better traction/stability in snow, soft sand, etc.
Jul 23rd, 2010 (10:20 am)http://gm-volt.com/2009/02/10/gm-announces-goodyear-to-supply-chevy-volt-low-rolling-resistance-tires-and-bose-to-supply-its-energy-efficient-stereo-system/
Jul 23rd, 2010 (10:34 am)I had assumed that the Volt would have some kind of pure electric braking. “Accumulator” suggests to me some kind of electro-hydraulic system in which something other than vacuum (a dedicated electric pump perhaps) maintains pressure for an electronically-controlled, yet essentially hydraulic braking mechanism. My only safety question here would be, is there any redundancy or fall-back mode in the event of electric pump failure? Otherwise, it sounds like a good solution; braking pressure is always optimal regardless of vehicle maneuvering: keeping hydraulics for the in-wheel mechanics, in order to take advantage of decades of engineering understanding (an electric actuator in a hot, pounding wheel would introduce significant unknowns). It also would maintain a familiar brake “feel” for today’s drivers.
I’m a southerner, so I don’t often see snow (not unknown, but extremely rare); however, black ice is much more common in an Atlanta winter than a northerner might think. I would think that since so much of the Volt’s operation is controlled by software, and that so many have this “traction control on snow” concern, that some kind of optional download or dealer patch would quickly be made available (if the braking system is not already capable of safe operation under these conditions).
Jul 23rd, 2010 (10:35 am)Great video. My two main concerns with the Volt are the weight at 3900 pounds and the low ground clearance. Tires will wear out fast and cost a fortune and the front end will be hitting the road a lot over bad bumps and potholes, etc. But I plan on driving carefully anyway to max out the all electric range!
Jul 23rd, 2010 (10:37 am)Any, preferably all, of the options would be very good.
Is there anyone from GM that can give us “the answer” to the traction resolution options on the VOLT?
Jul 23rd, 2010 (10:46 am)For any of us have who have seen this video before (a comment in an earlier thread may have brought it to the attention of some visitors); I would suggest that you watch it again. I just did, and found that this very question is addressed towards the end (and I had forgotten). See if her traction control statements don’t provide “the answer.”
BTW, I’ve found plenty of other GM videos on YouTube that I hadn’t seen which are worth a look.
+1
Jul 23rd, 2010 (10:48 am)Another fine job, Lyle. I would say “keep up the good work”, but I know that you will. Thanks, again, for the work that you are doing for all of us.
Jul 23rd, 2010 (10:50 am)Just another thought on this “Winter Traction Control” issue:
How hard would it be to let the computer know when it’s below freezing outside, to select a less aggressive algorithm? Probably the necessary sensor(s) are already present …
Jul 23rd, 2010 (10:56 am)LOL How did you know???? That is essentially what they told me at Toyota! The traction control is a SAFETY issue and you SHOULD NOT COMPLAIN about it. (This was a year before the s**t hit the fan for Toyota’s “we have no problems” attitude.) :+}
+1
Jul 23rd, 2010 (11:03 am)Actually, I would prefer the option for the driver to temporarily adjust or turn it off.
Many drivers “up here” have a lot of experience when conditions are snow covered and slippery. In most cases the need to reduce or turn off traction control is when starting on slippery surfaces that go up hill.
Just my 2 cents
Jul 23rd, 2010 (11:05 am)GM’s rough road testing
http://gm-volt.com/2009/11/05/video-gms-rough-road-chevy-volt-testing/
+1
Jul 23rd, 2010 (11:08 am)I have had ABS and Traction control on my last 2 GM’s (Grand Prix and the new Equinox). With the commute I have, down an escarpment, in Canada, winter driving, wet what ever. I will tell you that i will never be without it again.
The ABS COPLETELY lets you steer out in any emergency manoever and stops you faster. Locking tires slide ) traction is the result. Rolling tires wil have some traction / control.
As for traction control (TC). it is amazing in winter. My equinox (and the GP) I could turn it off. But (at least in the equinox AWD, it transfers the torque where needed..With it on,i CANNOT spin out on take off, or fishtail in a turn. (I know I tried it before I bought in December.)
GM’s TC and ABS work amazingly. (that is not kool aid, it is the only one I can authoritatively comment on as I only have GM’s)
+1
Jul 23rd, 2010 (11:08 am)I’m at a loss to imagine any situation on public roads where you want to forceably make all the tires loose adhesion with the road. At that point, the tires are no longer capable of providing any directional control whatsoever. Steering out of the situation is no longer an option.
+1
Jul 23rd, 2010 (11:10 am)I agree. I usually turn traction control off when i need to get going in snow (only when its really deep). But typically the traction control works well in normal snow conditions and detects slippage and reduces the engine torque.
I’ll also agree w/Mitch’s comments on ABS & TC. They are great assets I would not want to give up.
+1
Jul 23rd, 2010 (11:19 am)My personal experience with ABS braking is its great most of the time but the 20xx year GM versions seems to have issues when your on a gravel road and there are what I call repetitive ripple marks in the road.
They are 4 inch repetitive bumps created by trucks and cars, once one bump starts it creates another from the suspension jumping up then down. When you are braking over these ripples in the road the ABS seems to engage the whole time and you have extremely reduced braking what I call coasting. In this scenario its better to lock up the brakes and slow down from the friction as opposed to the ABS staying engaged the whole time.
Its kind of scary because when your going 35 – 45 MPH on a bumpy gravel road and these bumps are near intersections you start to break normally then the last 20 feet you basically have very little breaking when you need it the most, sometimes you can coast past your turn.
On dry roads the ABS works great.
Dont get me started on my traction control personally its totally worthless.
I remember one time, after snow was cleared from the parking lot, I pulled into a space with a slight downward angle and the tires were on the snow. Well I tried to back out but the tires would just spin, traction control only slowed the engine down. finally I took the cover off of my folding chair and shoved it under the tire and created my own traction control which worked.
You would think with all season tires, the weight on the front wheels from the engine you could easily back out of a space with a small patch of snow??
One a positive note I hit 270,000 miles on the 2.2 ecotec and is still going strong.
Maybe that perfect car will be created one day.
Jul 23rd, 2010 (11:31 am)Double-Jeapardy Question:
Since there is no conventional ‘transmission’ in a VOLT, can you tow it behind a motor home with all 4 wheels on the ground?
Jul 23rd, 2010 (11:37 am)I dont see why not.. just put it in neutral.
+2
Jul 23rd, 2010 (11:38 am)She’s a cutie…..
Drives aggressive….
Really the only reason I watched the video.
/I know….pig.
//good job on this one Lyle…. 2 thumbs up!
+1
Jul 23rd, 2010 (11:50 am)lol…..
Makes me wanna go back n get an engineering degree to work with/for or whatever with her. A rare sight in the engineering world if you ask me. She get’s my vote and her voice………….rrrrrrroow….
/wonder if she Facebooks?
Jul 23rd, 2010 (11:51 am)The closer we get to launch date, the more cautious GM will become about sensitive Volt data that could help the competition. That seems obvious.
Neverthess, GM still offer more information about the process of developing the Volt than any car manufacturer. We should appreciate that.
Jul 23rd, 2010 (11:51 am)Wait. It has neutral?
I thought we decided it didn’t?
+1
Jul 23rd, 2010 (11:55 am)For an electric motor, isn’t that the same thing as “Off”?
Jul 23rd, 2010 (11:56 am)I agree, but let’s say the CS mode in the Volt gets 50 MPG.
How quickly can a competitor stop what they are doing and do better?
I doubt they can in a few months.
Jul 23rd, 2010 (11:56 am)Then what is “Park” for?
I’m confused on the thing. I thought it didn’t have a “coast” mode.
Jul 23rd, 2010 (12:00 pm)OK, now I’m confused….
What locks the wheels when in “Park”? E Brake?
lol…
Jul 23rd, 2010 (12:03 pm)I guess i missed that conversation, but the shifter has PRNDM
Jul 23rd, 2010 (12:10 pm)But can I coast while driving down hill? To me, that is what neutral means.
Jul 23rd, 2010 (12:11 pm)I was absent that day.
“M”? What’s “M”?
Is it for…
“M”uthaf – - – that’s fast…..”
“M”uthaf – - – that’s some torque…”
“M”uthaf – - – hold on!!!!!!”
+1
Jul 23rd, 2010 (12:14 pm)Very good coverage and video… this is why I come back to this site. Educate the public. This is a refreshing change from the yellow journalism that is the media today. The VOLT is the largest leap in automotive technology in my lifetime… that’s 36 years of driving. Thank you GM engineers and all GM employees who are making the VOLT happen…your are doing a ecellent job! Do not rest.. there is a lot to do.
Jul 23rd, 2010 (12:15 pm)Some were guessing “mountain mode”.
Jul 23rd, 2010 (12:22 pm)OH!!!
OK, I remember now. Thanks for joggin the poor ol memory of mine.
That is the mode that gets you to CS mode sooner to reserve batt juice for climbing latter.
+1
Jul 23rd, 2010 (12:28 pm)Man Mode.
Monster Mode.
Magnificent Mode
Mercy Mode
McDonalds Mode
Macho Mode
Mouse Mode
Mini Mode (runs over the Mini-E)
Mystery Mode
Meander Mode
Melancholy Mode
Jul 23rd, 2010 (12:33 pm)Great video. She’s gorgeous. Lately Mercedes has been promoting their test courses. This is every bit up (for braking) as anything I’ve seen. I’d like to see some numbers – but that too will come eventually. Did I see front wheel spin? (Hard to tell in a video)
Anyways, VOLT’s handling looks to be competitive.
+1
Jul 23rd, 2010 (12:37 pm)Good info and video. I don’t understand the accumulator but I will look it up on line.
Thanks to all the GM workers who are working 10+ hrs a day to get a quality car out to us. They are making personal sacrifices that we will never know about. Having done that myself I understand it can be a thankless effort.
Slightly off topic. It would be interesting if someone put together a mock window sticker or an order form that captured all the features/options we know about the Volt and others that are TBD. There is a lot of information out there but not in one snapshot.
Thanks Lyle.
Hope we all get our Volts ASAP!
Jul 23rd, 2010 (12:50 pm)I was asking about towing because I seem to recall someone posted that the ‘electric drive unit’ was liquid cooled. If that is true, then I doubt you could tow it if the motor(s) need to be cooled. I am also pretty sure the VOLT is a little more complex than my son’s “slot cars” where the wheels spin freely even with no power.
Jul 23rd, 2010 (12:55 pm)That would be a whole lot of new invention just for the Volt. The hydraulic actuated disc brake has a lot of engineering momentum built up behind it.
(I’m assuming you’re talking about friction brakes actuated by electric servos).
Small trailers have used electric brakes for a really long time and they pretty much suck. Once you’ve towed a trailer with electro-hydraulic disc brakes you’ll never want to go back.
All they are doing is replacing the vacuum boost portion with a hydraulic cylinder. You still have the ability to push the pedal hard and apply the brakes with a loss of assist.
Systems like this are already popular on many luxury vehicles.
They are also used on many medium duty trucks, although many medium duty trucks utilize the power steering pump to charge the accumulator instead of using brake fluid pumped by an electric pump.
Jul 23rd, 2010 (1:02 pm)Sliding will get you stopped… but you will then have flat spot tires.
It’s better than running through an intersection, but not a good thing. For that reason I would like a kill switch on ABS.
Jul 23rd, 2010 (1:04 pm)As long as the transmission is splash lubricated.
Given that the transmission has a two mode heritage, it might have an electric oil pump for lubrication.
Jul 23rd, 2010 (1:06 pm)With the power off the motor doesn’t produce any heat, hence no need for cooling.
+2
Jul 23rd, 2010 (1:06 pm)There’s a trip down memory lane.
I find that Kool-Aid tastes best if you use the little packets, cut the sugar by a third to a half and use about a 75% water / 25% rum mix instead of straight water.
Jul 23rd, 2010 (1:09 pm)A good place to read up on it is here:
http://hydratechbraking.com/hydroboost_faq_old/
I’m sure the Volt will use an electric powered pump instead of tying it to the steering system. (Jeep does this for one.)
-5
Jul 23rd, 2010 (1:10 pm)They offer plenty of useless information, supplemented by hype. They switched to a narrower shifter? Who cares?
What sets this vehicle apart? The drivetrain and the fuel requirements. Do they release information on their “Freedom (hype) Drive?” Nope. People want to know the CS mileage and the price, these are the questions that are routinely asked and GM tap-dances around them.
I’ sure I can look forward to hearing about the floor mats and engine bay lighting.
Jul 23rd, 2010 (1:19 pm)Never mind the drive-train, I want this SUSPENSION! I don’t see any lean or sway in the corners! Sweet!
+1
Jul 23rd, 2010 (1:29 pm)Sounds like a calendar …
Jul 23rd, 2010 (1:34 pm)On GM cars with traction control they have a switch to turn them off just for that purpose. If you are on ice or in deep snow or at an intersection and have to goose it to get into traffic you can shut off traction control to let the wheels spin and get you going.
Tom C
Jul 23rd, 2010 (1:34 pm)Even at relatively low speeds, I was extremely impressed by the complete lack of lean in our marked out S curves (when I drove a prototype in NY this past March). I am not a ‘Performance Car’ person by any stretch, but this and the strong sense of stability overall lead me to start making my “people will be buying a Volt for the performance” comment. I don’t know how Volt handling compares to a real “performance car,” but I suspect it will knock the living snot out of the cars it is currently compared to.
Jul 23rd, 2010 (2:12 pm)
Jul 23rd, 2010 (2:15 pm)I guessed that, or some said manual. I think it may increase the regernative braking, acting sort of like a low gear “L” in typical cars. (or maybe thats what AS1-2 is for?)
Jul 23rd, 2010 (2:28 pm)What transmission, you lost me?
Jul 23rd, 2010 (2:29 pm)I really think “M” refers to the new mountain mode GM has said they’ve added, although it may have other effects in non-mountain driving as well. Also, thanks to your excellent and diligent efforts that gave us the very helpful annotated photo below, I deduce that the close location of AS1-2 to the ECO/SPORT switch supports my hypothesis that the “AS1-2″ controls the car’s “automatic stability” modes as I explained in post #51 here.
Jul 23rd, 2010 (2:32 pm)Depends on how the off switch is wired. From the small permanent-magnet DC motors I’ve played with, “open” (where you just unplug the motor) allows the motor to freewheel, but “shorted” (where you unplug the power and connect the motors leads together) makes the motor resist being turned. Both are conditions that I would consider “off”. I’ve never tried this with an AC motor, or a motor that doesn’t use permanent magnets.
But, the Volt is a car, not a benchtop toy. I suspect that it has some sort of parking-gear in their axle. It pretty-much has to have a way to lock the wheels when the car is turned off, because some people never use the parking brake and never will, since we have some sort of cultural hangup about that requires that nobody ever have to learn anything new about how to drive a car — even a fundamentally different kind of car.
So, I wouldn’t tow the Volt on all 4 wheels just yet…
Jul 23rd, 2010 (2:35 pm)Small motors are usually permanent magnet. The Volt uses an Induction electric motor – no magnets.
Jul 23rd, 2010 (2:41 pm)I’m not sure if this is quite right. An accumulator is an air over oil system. The presurized air in the vessel provides the hydraulic pressure. I use these all the time to get around having to use a hydraulic power unit. Just pressurize a tank w/system air and you get hydraulic pressure.
Jul 23rd, 2010 (3:33 pm)To further that, an AC induction motor requires the electrical excitation for the stator coils for either regen or power for motion. If the motor is electrically an “Open”, no current flow or voltage applied, it’s freewheelin!
Jul 23rd, 2010 (3:47 pm)Does anyone know how fast the Volt will go in reverse? Imagine cruising at 70 mph in reverse through morning traffic…that would wake everyone up!
/just curious.
+1
Jul 23rd, 2010 (3:48 pm)That’s what “transparent” means. We can easily see through the lack of substance.
Sorry, but it is rather absurd that so much practical consumer purchase information is still being withheld by GM and on the Toyota side some consumers (non-employees) are now getting opportunities to putter around with a plug-in Prius on their own at any speed & charge-level they want.
Jul 23rd, 2010 (4:11 pm)Hey john1701a, dude, what info do you have on the plugin Prius? More specific the all elec range? What are they seeing/getting under best case (hypermile) scenario and worst case (my wife driving yelling at everyone) scenario on these drives they are doing?
As I recall, certain sites like ABG/Motortrend/etc…, were posting 10-13 miles all electric up to 60mph (100km/h).
I’m just curious cuz even the 10 mile AER will work perfect for me. And I *think* I may be able to afford one if it is less than the LEAF…….ok, quite a bit less than the LEAF.
/all I have ever read were “speculations”.
Jul 23rd, 2010 (4:15 pm)lol…
Contrary to what many think, and most think that the speed in one direction is the same the other direction, it will probably be much less if not limited electrically.
An electric motor for traction will usually be “tuned” for best performance by the “Timing” of the AC waves, especially a 3 phase motor. It’s even more critical on those DC “Warp” motors from NetGain.
-2
Jul 23rd, 2010 (4:26 pm)It’s too bad GM can’t find a way to sell some of this ‘transparency” for actual revenue and be more like Ford. You know, report some significant profits.
Jul 23rd, 2010 (4:41 pm)A brushed DC motor can have different characteristics forwards and backwards if the brushes are not set at 90° electrical from the field winding. If the brushes are “square” electrically to the field windings then there is no difference forwards or backwards. This is demonstrated daily on diesel electric locomotives and older subway trains that happily run full speed either way.
To an AC motor, the only difference possible is with the cooling fan. Since the Volt motor is liquid cooled, I assure you it doesn’t give a rip about rotation direction.
Jul 23rd, 2010 (4:44 pm)Given that I own a truck that uses this exact system from the factory, I can assure you it’s all correct.
The initial charge is nitrogen at 800 PSI. There isn’t any hydraulic fluid in it when it’s charged. It is then filled with hydraulic fluid by the power steering pump until there is 1500 PSI.
Jul 23rd, 2010 (4:47 pm)Well, the correct term would be transaxle. The electric motor turns over faster than the wheel speed. There is a reduction gear to do this. There is also a differential. Put the two together and you have a transaxle.
Jul 23rd, 2010 (5:10 pm)The reverse speed of the Volt is limited, with software. There is no difference in effective ratio, unlike conventional reverse; which sends an engine’s single-direction rotation through additional gears (changing the ratio, in most cases).
Jul 23rd, 2010 (5:34 pm)Valarie says,
“My entire life, I’ve been interested in two things: racing and cars. It all began when I was a kid growing up in Galveston, Tex., hanging out at my mom’s skydiving “drop bone,” where skydivers landed from their high-sky plunge. Years of exposure to these crazed skydivers ignited the adrenaline junkie in me. Paired with my love for racing and cars, it was a no-brainer to go to school for engineering and pursue an automotive career. And there’s my confession: my name is Valarie and I’m an adrenaline junkie turned engineer.
“When I got to the University of Missouri – Rolla (now known as Missouri University of Science and Technology), I knew I wanted to get my bachelor’s degree in mechanical engineering and get involved with automotive-related student groups. My love of racing made the choice between the solar car and formula car teams easy. If I wasn’t in class, I was almost always in the formula car shop designing and fabricating our racecar. Really! I spent about 40 to 50 hours a week there. I started off in the drive train group, moved on to the powertrain group as a group leader; and finally, became team president, during the summer break and fall semester of my senior year.
“Since GM recruits directly from my college, and because I had already interned for the company in 2004, no one was surprised when I started working full-time for GM in 2006. I started off working in the Stabilitrak 3.0 group, learning how to calibrate electronic stability control (ESC) of the Cadillac STS. After that, I was off to the hybrid group, doing chassis control on hybrid trucks.
“Right now, as a Performance Integration Engineer on Chassis Control (ABS, Traction Control and ESC), I’m working on the Chevrolet Volt electric vehicle with extended range among other vehicle programs. I get to do cool things like take the cars up to GM’s winter test facility in the Upper Peninsula during the winter months to test them on the giant ice pads and snow fields. And I get paid for it!
“The best part of my job is knowing I’m personally contributing to our customers’ driving experience and safety. Even though the software is already in the car, my job is to drive it and make any necessary tweaks to fine-tune its performance. That way, once the car is in the customer’s hands, it will run as seamlessly as possible.
“The best part of my day? Well, that’s a tossup. When I’m not running tests or driving cars on the track and through snow fields at work, I spend nearly all of my free time riding something exciting – either on the race track with my Yamaha R-6 motorcycle, or my two Arabian horses, MSU Superstitious and MSU Missile Man AM. Even though my schedule is packed between crazy test-driving maneuvers, racing and horses, I can honestly say that I love every minute of it and wouldn’t change a thing.”
Jul 23rd, 2010 (7:37 pm)Michael:
Valarie already got one proposal. What are you doing, trying to get a few more?
Jul 23rd, 2010 (7:44 pm)I just wanted everyone to see what a well rounded person she is and the driving skills are not an act.
Jul 23rd, 2010 (8:40 pm)She sounds like a fun girl, …. knows what a “drop bone” is and all.
Jul 23rd, 2010 (10:02 pm)excellent ! Thanks for the info.
Jul 24th, 2010 (1:27 am)I am sure it is legally required to be able to stop if power assist fails.
Jul 24th, 2010 (2:14 am)Ra, ra! Go Volt!
Jul 24th, 2010 (2:30 pm)The Volt handles like the smoothest race car ever driven.