...and I had the guy autograph my copy of the magazine when I saw him at Makerfaire.
The San mateo Maker Faire? That wasn't the same guy featured in the magazine. Told me that he'd never heard of it. (unless he was pulling my leg - which is entirely possible.)
No, I went to the one in Orlando that I started a thread about. If you talked to him about MakerFaires, that's likely the reason why he and his EV club were at the one I went to.
Keith wrote: Once the batteries are depleted, can the gas engine recharge them while also hauling the car down the road at 60 mph?
Yes and no. This where GM got into the quandary. Originally the generator engine (gas, diesel, rotary, whatever) wasn't going to connect to the drive wheels at all. Basically you could have mounted the power plant on the roof because the electric motor(s?) were the only means of propulsion.
Later some techies figured out that the Volt's gas engine can power the actually driven wheel, but only in extremely specific situations (IIRC, it's like 65MPH+ with a dead battery) as it's just more efficient. Thus making it a "Hybrid" as opposed to an extended-range-EV (like the Fisker).
So in a Targa type situation (speed changes) it wouldn't work, but maybe for inter-stage cruises?
Keith wrote: Here's a Volt question, brought on by the Targa suggestion. Once the batteries are depleted, can the gas engine recharge them while also hauling the car down the road at 60 mph?
It won't fully recharge the batteries. In normal Charge Sustaining (CS) mode, the car runs the engine with the intent of keeping the State Of Charge (SOC) at about 22%. Note that the gas engine produces about 85hp but the total system output can be 150hp. In other words, the gas engine does not produce enough power to sustain maximum output. To accommodate power draws greater than 85ish hp, the car maintains about a 1kw/h buffer. It will draw down to as low as 15% SOC, then you are in Reduced Propulsion Mode, driving an 85hp, 3700lb car, presumably up a long, steep hill with the engine wailing away at peak hp. You are probably not very pleased with your driving experience at that point.
I'm not sure you'd ever encounter this cruising steady state on the flats. Maybe at 100mph? It easily does 80+ all day long. You will hit it on a mountain pass out west though.
So they added a "Mountain Mode", which configures the car to maintain about 45% SOC, extending the buffer to about 4kw/h. GM claims this is enough to get over any major climb in the US at "normal highway speeds".
Back to your question: if you run the battery down to "empty" (22% SOC) and engage Mountain Mode when your NOT climbing across the Rockies, it will charge it back up to 45% SOC after about 20 minutes of a pleasant 4 cylinder symphony of 2800rpm/WOT. From the user standpoint, it's about 1/3 charged at that point.
Personally, when I'm on a long trip running the gas engine, I'll engage MM 10 minutes before I exit so I can switch back to normal and drive along "electrically" (at that point you're really using stored gasoline energy if you chose to be pedantic about it) on surface streets.
Note that none of this is related to whether the engine is clutched in "directly". It can charge the battery whether it is or not.
""
If anyone really cares to learn what the heck the mess of motors, clutches, and ICE do in this car, I encourage setting aside 1/2 an hour to view the Chevy Volt Powertrain Deep Dive on youtube, presented by Pamela Fletcher, Chief Powertrain Engineer on the car. The quality is handheld-video-in-the-audience but there's a LOT of information.
http://www.youtube.com/watch?v=d9-9atMw6Zs
mfennell wrote: If anyone really cares to learn what the heck the mess of motors, clutches, and ICE do in this car, I encourage setting aside 1/2 an hour to view the Chevy Volt Powertrain Deep Dive on youtube, presented by Pamela Fletcher, Chief Powertrain Engineer on the car. The quality is handheld-video-in-the-audience but there's a LOT of information. http://www.youtube.com/watch?v=d9-9atMw6Zs
Just watched that whole video, and now I feel stupider than ever. I need to go watch a VanDamme movie or something.
To paraphrase her explanation of the Volt's powertrain:
"The Volt is a witch, and operates through principles of demon magick."
jg
In the Targa, you run a timed stage (assuming we're in Targa division) at maximum attack. I'm assuming this will deplete the batteries - maybe not on one stage, but some of them are fairly lengthy and involve sustained high speeds.
Then you have to go to the next stage. Sometimes it's just a matter of turning around and blasting back from whence you came, sometimes it's 130 km away on a 100 km/h highway. Thus my question about battery recharge behavior. It sounds as if Mountain Man Mode would be helpful here to bring the batteries up somewhat, but you would find yourself with a car less capable at the end of the day than it had been at the start.
Yes?
Sounds like it's time to hack the system and develop Targa Mode, where the gas engine labors mightily to pack a whole bunch of electrons into the batteries while on a transit, and thus gird its loins for the next stage.
Keith wrote: In the Targa, you run a timed stage (assuming we're in Targa division) at maximum attack. I'm assuming this will deplete the batteries - maybe not on one stage, but some of them are fairly lengthy and involve sustained high speeds. Then you have to go to the next stage. Sometimes it's just a matter of turning around and blasting back from whence you came, sometimes it's 130 km away on a 100 km/h highway. Thus my question about battery recharge behavior. It sounds as if Mountain Man Mode would be helpful here to bring the batteries up somewhat, but you would find yourself with a car less capable at the end of the day than it had been at the start. Yes? Sounds like it's time to hack the system and develop Targa Mode, where the gas engine labors mightily to pack a whole bunch of electrons into the batteries while on a transit, and thus gird its loins for the next stage.
What you're looking for is theoretical if the driver had full control and monitoring ability over the various systems. Unfortunately, you don't have either of those things. Well, unfortunately for smart people, but most people aren't smart. It would be a disaster for dumb people to have access to all that voltage.
My guess is there's a way to work within the parameters required by the computers to at least create "best case" scenarios for each stage.
jg
Keith wrote: Sounds like it's time to hack the system and develop Targa Mode, where the gas engine labors mightily to pack a whole bunch of electrons into the batteries while on a transit, and thus gird its loins for the next stage.
That would be pretty interesting but I wouldn't hold my breath on someone reverse engineering the code in the car any time soon. It's not like a 'normal' car where all the engine management functions are in a well-understood Bosch or Siemens ECU. It would be more like hacking BMW iDrive X100.
The Targa would not be much fun IMHO. The battery supplies the energy equivalent of about 40oz of gasoline (10.4kw/h out of the 16kw/h pack). The motor can draw 111kw. You might get 15 minutes of EV, then spend the rest of the day listening to the poor 1.4L thrashing about trying to keep up, wishing you had brought a more appropriate car.
mfennell wrote: If anyone really cares to learn what the heck the mess of motors, clutches, and ICE do in this car, I encourage setting aside 1/2 an hour to view the Chevy Volt Powertrain Deep Dive on youtube, presented by Pamela Fletcher, Chief Powertrain Engineer on the car. The quality is handheld-video-in-the-audience but there's a LOT of information. http://www.youtube.com/watch?v=d9-9atMw6Zs
O. M. G.
She is so hot!
mfennell wrote:Keith wrote: Sounds like it's time to hack the system and develop Targa Mode, where the gas engine labors mightily to pack a whole bunch of electrons into the batteries while on a transit, and thus gird its loins for the next stage.That would be pretty interesting but I wouldn't hold my breath on someone reverse engineering the code in the car any time soon. It's not like a 'normal' car where all the engine management functions are in a well-understood Bosch or Siemens ECU. It would be more like hacking BMW iDrive X100. The Targa would not be much fun IMHO. The battery supplies the energy equivalent of about 40oz of gasoline (10.4kw/h out of the 16kw/h pack). The motor can draw 111kw. You might get 15 minutes of EV, then spend the rest of the day listening to the poor 1.4L thrashing about trying to keep up, wishing you had brought a more appropriate car.
Oh, I know it would be hard to hack. But you know GM could do it if they wanted 
A really competitive Targa car isn't that much fun on the transit stages anyhow, I wear ear protection in mine as we watch the heatshielding melting on the transmission tunnel. But 15 minutes of EV time followed by (say) 45 minutes of charge time might work, especially if you can convince the gas engine to recharge the batteries when the car is idling.
Obviously this is just imagination, as JG's not going to strip out his own car and it's unlikely anyone's going to make a pitch to GM to run a Volt in the Targa instead of a Camaro ZL1. But it does help identify how the car works in a performance setting.
Semi-related, the EV/Hybrid class at Pike's Peak is shaking up to be really, really interesting. Seems like that would be a good place to "show what the Volt can do", IMO.
Keith wrote: Obviously this is just imagination, as JG's not going to strip out his own car and it's unlikely anyone's going to make a pitch to GM to run a Volt in the Targa instead of a Camaro ZL1. But it does help identify how the car works in a performance setting.
Heck if I thought I could get away with it I'd drive a Volt, provided they provided the car and parts, just to run the Targa. I bet there would be some interesting/explosive results. But no one is going to take the amateur racer / professional mechanic seriously without some actual semi professional race results.
Keith wrote:mfennell wrote:Oh, I know it would be hard to hack. But you know GM could do it if they wantedKeith wrote: Sounds like it's time to hack the system and develop Targa Mode, where the gas engine labors mightily to pack a whole bunch of electrons into the batteries while on a transit, and thus gird its loins for the next stage.That would be pretty interesting but I wouldn't hold my breath on someone reverse engineering the code in the car any time soon.
Hobbit (the guy who wrote netcat) could to it. He is not just a luminary in computer security, he's also become fairly well known of late for modifying priuses in many ways.
The0retical wrote:Keith wrote: Obviously this is just imagination, as JG's not going to strip out his own car and it's unlikely anyone's going to make a pitch to GM to run a Volt in the Targa instead of a Camaro ZL1. But it does help identify how the car works in a performance setting.Heck if I thought I could get away with it I'd drive a Volt, provided they provided the car and parts, just to run the Targa. I bet there would be some interesting/explosive results. But no one is going to take the amateur racer / professional mechanic seriously without some actual semi professional race results.
I think most of us would drive just about anything in the Targa, provided someone else provided the car and the parts
As for not being taken seriously, don't write yourself off until you try it. You're not in the position to say no, the potential sponsor is. I do think that if JG wanted to take a serious run at Targa with my help, we should be able to get GM's attention. But you'll notice he hasn't made any comments to that end, it's the rest of us that are planning this for him.
Keith wrote: A really competitive Targa car isn't that much fun on the transit stages anyhow, I wear ear protection in mine as we watch the heatshielding melting on the transmission tunnel. But 15 minutes of EV time followed by (say) 45 minutes of charge time might work, especially if you can convince the gas engine to recharge the batteries when the car is idling.
The car doesn't 'idle'. :)
HOWEVER, you reminded me of something. If you pop the hood with the car ON, the ICE starts up and idles. GM says it's a safety thing - they want the owner to know the car is ON so they don't go poking around and encounter 360VDC. They say it's not for charging but a gm-volt poster insists he has charged his car to full simply by opening the hood and letting it run.
At idle, I imagine that takes forever and is terribly inefficient. The "awesome point" for converting gasoline to electricity for charging is around 2800rpm/WOT. The system burns about 240g of gasoline per kW/h generated at that point. There's a nice efficiency map in one of the SAE papers.
[nerdy maths] The battery exposes 10.4 kW/h, so it would take (240*10.4/1000) approximately 2.5kg of gasoline, or about .92 gallons to fully charge it. The EPA says the car travels 35 miles with that 10.4 kW/h. 35/.92 = 38 miles/gallon. The EPA gasoline rating is 37 MPG. I don't know if that's a coincidence or not but I do know the calibrators gave up a little in absolute MPG for NVH considerations. [/nerdy maths]
Keith wrote: But you'll notice he hasn't made any comments to that end, it's the rest of us that are planning this for him.
Please continue. Before long you'll have me running LeMans :)
Nothing is set in stone for the car, other than I don't want to get hit with a $42,000 bill when I turn it in in three years. In the meantime, we're letting things develop naturally. I'm tentatively planning on running the PDX at Sebring next month if I can work through some family schedule stuff. That event should tell us a LOT about the true nature of the car.
jg
It's a 1:1 scale slot car.
My prediction is that 3 years and $13K from now, JG will wish he spent 3 years and $13K converting a lightweight mid engined car like an MR2 over to electric power.
In fact, a $13K Challenge between a Volt and a homegrown setup would make for some good readin'.
Hmm, Le Mans....
Okay, I can see how the car wouldn't "idle". But since we're magically reprogramming the drivetrain logic for Targa mode, it would seem that it would be possible to have the ICE kick in when the car is at rest if it is trying to recharge the battery.
I'm trying to imagine what this would be like to drive The engine is just roaring away at 2800 rpm as you sit, as you creep forward, as you cruise. It would not necessarily be pleasant.
Steve Chryssos wrote: O. M. G. She is so hot!
I bet she drives a GM program car Chevrolet Suburban.
JG Pasterjak wrote: I'm tentatively planning on running the PDX at Sebring next month if I can work through some family schedule stuff. That event should tell us a LOT about the true nature of the car.
I'll save you the trouble: the true nature of the car is ... it's an awesome commuter. It handles pretty well for what it is (will rotate under braking as I mentioned before) but I'm not so sure it will be the highlight of your track driving experience.
Nevertheless, I look forward to the track results of 149hp/3700lbs/580 treadwear tires if only because the idea is so ridiculous. :) At least the brakes should be OK. Regen is pretty strong, handling almost all braking duties up to about 0.3g deceleration.
Since everyone insists on comparing them, you must bring a Prius too!
Pete240Z wrote: I bet she drives a GM program car Chevrolet Suburban.
The guy who did the ICE calibration drives a twin-turbo C6 with Grand Sport bodywork.
I find this all very interesting.
mfennell wrote:JG Pasterjak wrote: I'm tentatively planning on running the PDX at Sebring next month if I can work through some family schedule stuff. That event should tell us a LOT about the true nature of the car.I'll save you the trouble: the true nature of the car is ... it's an awesome commuter. It handles pretty well for what it is (will rotate under braking as I mentioned before) but I'm not so sure it will be the highlight of your track driving experience. Nevertheless, I look forward to the track results of 149hp/3700lbs/580 treadwear tires if only because the idea is so ridiculous. :) At least the brakes should be OK. Regen is pretty strong, handling almost all braking duties up to about 0.3g deceleration. Since everyone insists on comparing them, you must bring a Prius too!
My prediction as well.
I would like to be able to get at least a few laps on electric, though. Obviously there won't be time to charge between sessions, but at least my morning session can be juiced. Maybe I'll just run an extension cord from my hotel room.
jg
In reply to mfennell:
just have to say.....I love the variety of the cars in your garage!
You'll need to log in to post.
