carguy123 wrote: But even if this were groundbreaking, which it's not, Toyota would find a way to make it boring.
Groundbreaking is relative.
The industry has spent billions on other ideas ( including Toyota) and this simple development beat them all. At almost no cost.
To many of us, it groundbreaking. And frustrating in other ways. Very frustrating.
alfadriver wrote:carguy123 wrote: But even if this were groundbreaking, which it's not, Toyota would find a way to make it boring.Groundbreaking is relative. The industry has spent billions on other ideas ( including Toyota) and this simple development beat them all. At almost no cost. To many of us, it groundbreaking. And frustrating in other ways. Very frustrating.
Why frustrating? Because it wasn't you or because you were working in other areas?
To comment on the earlier conversation, our engines are rated at the equivalent of WOT. I suspect that someone could make great use of that efficiency island with clever throttle mapping and transmission scheduling.
In reply to tuna55:
No, nothing personal to me- my career is firmly stalled and am just waiting until I'm fully vested. I'm more focused on anything that delivers more profit sharing. That's why it's frustrating.
On the BSFC note- when you look at that map, it's hard to realize how little of it is actually used. Any of you who have MS or anything you put in, record some daily driving. That's the real context that the engines are used for 90% of the owners. You'd be surprised how hard it is to efficiently make 5-25 hp. And when I saw the Toyota chart (assuming it's real), that's what impressed me.
Too many people in the industry are focused on the peak number, not seeing that so few people really use WOT. We want 500lb-ft of torque at 1500rpm, not realizing that unless you are towing a large trailer up a hill, by the time you get anywhere near that torque, you are way up in engine speed. They are advertising numbers that compromise the design of a powertrain for real people. Which causes upset customers, and they do sue (I'm aware of 4 for different OEMs related to a specific technology that they are doing).
Enough of that rant.
I'm very impressed with this Toyota engine, and I hope a lot of good comes from it. For Ford, GM, Fiat, etc.
No surprise on the electric water pump... they've done that for years on the Prius. Actually, my only surprise is that it didn't happen sooner. I'd like to see the electric oil pump as well.
One thing I did find surprising - the new engine has much more stroke than the 'current' engine, yet they show it with a substantially higher redline. This thing has a 103.4mm stroke, so nearly 7k is spinning pretty damn fast.
It always amazes me what can be done with simple tweaking & optimizing of existing tech vs. a new technology.
alfadriver wrote: Most engines are best at about 80% output in the 2000rpm range. But that's way too much to use in real life.
Steady state, yes. Accelerating & hills push most smaller engines into that range easily (assuming no kick-down).
The sweet spot for the engine in my DD is right around there. Power values are around 40hp at the center. Not exactly blistering acceleration in a ~2700lb car with driver/stuff.
In reply to ProDarwin:
But that's exactly the point... ideally the sweet spot would be at cruise, not acceleration. So 40hp is making too much power for the sweet spot unless you're cruising at 80-90mph.
Knurled wrote: In reply to ProDarwin: But that's exactly the point... ideally the sweet spot would be at cruise, not acceleration. So 40hp is making too much power for the sweet spot unless you're cruising at 80-90mph.
Sorta, but cruising at 90mph wouldn't be in the sweet spot unless I had a 0.400 5th gear 
. Yeah, getting a sweet spot at low-medium rpm, low load is pretty difficult to do - which is why hybrids and Atkinson cycles make a lot of sense.
Also, it depends how long you spend cruising, if you accelerate for 10 seconds using 40hp, and cruise for 100seconds using 4 hp, then BSFC improvements in each area would result in equal improvements. Im actually curious on the FTP-75 or UDDS what the amount of total energy consumption is due to acceleration vs RR+WR.
ProDarwin wrote:alfadriver wrote: Most engines are best at about 80% output in the 2000rpm range. But that's way too much to use in real life.Steady state, yes. Accelerating & hills push most smaller engines into that range easily (assuming no kick-down). The sweet spot for the engine in my DD is right around there. Power values are around 40hp at the center. Not exactly blistering acceleration in a ~2700lb car with driver/stuff.
Not really, and the time you spend there is very short. At best, it's a transient location, and even 40hp worth of acceleration will take you out of the area very quickly.
If you are using 40hp to run steady state, something is very badly wrong. Your car probably uses around 20hp to go 70mph.
ProDarwin wrote:Knurled wrote: In reply to ProDarwin: But that's exactly the point... ideally the sweet spot would be at cruise, not acceleration. So 40hp is making too much power for the sweet spot unless you're cruising at 80-90mph.Sorta, but cruising at 90mph wouldn't be in the sweet spot unless I had a 0.400 5th gear
Just to point out that, yes, there are people who drive like that. But they are very, very rare.
On an FTP, for most vehicles, the acceleration is about twice the energy in the cruising. Backward for the highway part (which is a lot more cruising). Haven't paid that much attention to the US06 part- but watching that being driven- not many people drive like that- it's super aggressive.
alfadriver wrote:ProDarwin wrote:Not really, and the time you spend there is very short. At best, it's a transient location, and even 40hp worth of acceleration will take you out of the area very quickly. If you are using 40hp to run steady state, something is very badly wrong. Your car probably uses around 20hp to go 70mph.alfadriver wrote: Most engines are best at about 80% output in the 2000rpm range. But that's way too much to use in real life.Steady state, yes. Accelerating & hills push most smaller engines into that range easily (assuming no kick-down). The sweet spot for the engine in my DD is right around there. Power values are around 40hp at the center. Not exactly blistering acceleration in a ~2700lb car with driver/stuff.
Absolutely.
I just checked the UDDS cycle with my car and it crosses the 25kw mark only once. Of course, that calls into question how realistic that cycle is, with a max accel of only 1.47m/s^2 or 0.15G and zero elevation change.
I should dig up a datalog of my commute again and check what a more realistic numbers are.
Fun question that few would have the potential to answer with any certainty:
Would there ever be an engine peaky enough in BSFC in terms of RPM and throttle position that would actually increase fuel efficiency by increasing drag on the vehicle, either through speed or something else?
Meaning, would a vehicle ever get better mpg at a higher speed than a lower one?
I think yes, because I think I owned one. I imagine those situations are unique though.
tuna55 wrote: Meaning, would a vehicle ever get better mpg at a higher speed than a lower one?
Depending on how draggy the vehicle is, how it's geared and engine BSFC, this is quite possible. There will always be a "peak mpg" speed (or sometimes a range within which mpg is almost identical or more than 1 peak). Going slower or faster than the peak will result in worse mpg.
Slower than peak would either put you at too low an rpm to be efficient or put you down a gear, too fast is either too much rpm or enough power demand from aero drag to cause mpg to suffer.
Generally a more aerodynamic vehicle and one with taller gearing will hit peak mpg at a higher speed than something draggy with short gearing.
tuna55 wrote: Fun question that few would have the potential to answer with any certainty: Would there ever be an engine peaky enough in BSFC in terms of RPM and throttle position that would actually increase fuel efficiency by increasing drag on the vehicle, either through speed or something else? Meaning, would a vehicle ever get better mpg at a higher speed than a lower one? I think yes, because I think I owned one. I imagine those situations are unique though.
I would say that for a vehicle with anything resembling typical gearing, you could only get better efficiency at a higher speed within the speed range of first gear - or on a CVT, within the range of speeds that could be reached at the lowest geared position.
When driving on the street it might seem that a car gets better mileage at higher speeds because there are just a few speed ranges you drive in on the street (crawling in traffic / open city & residential streets / highway cruising), and the car could very well do best at the highest range without unusual gearing if the engine is very peaky.
tuna55 wrote: Fun question that few would have the potential to answer with any certainty: Would there ever be an engine peaky enough in BSFC in terms of RPM and throttle position that would actually increase fuel efficiency by increasing drag on the vehicle, either through speed or something else? Meaning, would a vehicle ever get better mpg at a higher speed than a lower one? I think yes, because I think I owned one. I imagine those situations are unique though.
That's kind of a trick question.
Mostly because- which is more- the increase in power or the decrease in BSFC? If the power increase is more (which to me, is more likely) that will still work out to use more fuel.
On the other hand it does make a lot of sense to me that an engine can get better fuel economy making the same power at a higher speed than a lower one.
The gray area for that is in the 30-55 mph range where the aero drag starts taking over from the linear drag. Plus, as odd as it sounds, it's more difficult to do a steady slow speed- and all those tiny transients kill fuel economy.
Making 4hp is a bitch, making 40hp is easy. But the BSFC difference has to be 10x to get better fuel economy at 40hp than 4hp.
alfadriver wrote: Making 4hp is a bitch, making 40hp is easy. But the BSFC difference has to be 10x to get better fuel economy at 40hp than 4hp.
Not quite. 10x better would give the same fuel flow per unit of time. But if making that extra power means you're going 2x as fast, you'd only need a BSFC improvement of 5x to get the same fuel economy.
rslifkin wrote:alfadriver wrote: Making 4hp is a bitch, making 40hp is easy. But the BSFC difference has to be 10x to get better fuel economy at 40hp than 4hp.Not quite. 10x better would give the same fuel flow per unit of time. But if making that extra power means you're going 2x as fast, you'd only need a BSFC improvement of 5x to get the same fuel economy.
Ok, that's true, but it's still a point that normally it takes a lot more power to go twice as fast. Up to a point, it's pretty linear, but it quickly does not become that. My math example kinda sucked.
But that kind of change in BSFC doesn't happen, unless something odd is going on.
alfadriver wrote:rslifkin wrote:Ok, that's true, but it's still a point that normally it takes a lot more power to go twice as fast. Up to a point, it's pretty linear, but it quickly does not become that. My math example kinda sucked. But that kind of change in BSFC doesn't happen, unless something odd is going on.alfadriver wrote: Making 4hp is a bitch, making 40hp is easy. But the BSFC difference has to be 10x to get better fuel economy at 40hp than 4hp.Not quite. 10x better would give the same fuel flow per unit of time. But if making that extra power means you're going 2x as fast, you'd only need a BSFC improvement of 5x to get the same fuel economy.
I got better fuel economy in an older Civic at 80 mph than I did at 70 mph. I know the drag was higher, my only reasoning was that BSFC was way better at that load, enough to overcome the drag increases.
tuna55 wrote: I got better fuel economy in an older Civic at 80 mph than I did at 70 mph. I know the drag was higher, my only reasoning was that BSFC was way better at that load, enough to overcome the drag increases.
Makes sense. If the car had a CVT, you could've found that 80mph sweet spot in the engine's power at 70mph.
Tuna: It is not terribly hard to convert the drag to effective required horsepower. That compared to the engine rpm and throttle required to make just overcome the aero/mechanical horespower will give you the answer to your riddle. There are likely to be several 'efficiency peaks' depending on gearing/revs/throttle/drag.
I outlined the drag calculation method (combined aero and mechanical) in a sidebar for JG when he was looking at the mileage change due to tire changes on a NewBeetle. The tires made a huge difference, suprise.
Well, all my cars get better fuel mileage at 1 mph than they do at 0 mph. So at least you have and edge condition in your favor.
tuna55 wrote:alfadriver wrote:I got better fuel economy in an older Civic at 80 mph than I did at 70 mph. I know the drag was higher, my only reasoning was that BSFC was way better at that load, enough to overcome the drag increases.rslifkin wrote:Ok, that's true, but it's still a point that normally it takes a lot more power to go twice as fast. Up to a point, it's pretty linear, but it quickly does not become that. My math example kinda sucked. But that kind of change in BSFC doesn't happen, unless something odd is going on.alfadriver wrote: Making 4hp is a bitch, making 40hp is easy. But the BSFC difference has to be 10x to get better fuel economy at 40hp than 4hp.Not quite. 10x better would give the same fuel flow per unit of time. But if making that extra power means you're going 2x as fast, you'd only need a BSFC improvement of 5x to get the same fuel economy.
A good question is why. How different is the engine running at those two states?
A probable possibility is that at 70mph, it was running stoich, but had real issues with knock, and retarded the spark to prevent that- but at 80, you ran a little rich, putting all of that spark back. So the loss of efficiency due to spark is more than the enrichment.
Interesting. Glad to see innovation like this.
It's not really innovation. That's why it's a double edged sword to me. Glad someone's doing it, aggravated that it took so long. There is no single thing outlined in that article or video that needed any explaining to me. It was all pretty intuitive and obvious. It mostly makes me think that the only reason this got posted in 2017 and not 2007 is that there was finally the right mixture of incentives to just put the time in and implement things that were always pretty certain to work. I'll elect not to go on a rant about under-regulation... this time. Anyway, in a world full of stupidity and bad news i'll take the good where i can get it and just hope the rest of the OEMs implement similarly in the near future. 
tuna55 wrote: Fun question that few would have the potential to answer with any certainty: Would there ever be an engine peaky enough in BSFC in terms of RPM and throttle position that would actually increase fuel efficiency by increasing drag on the vehicle, either through speed or something else? Meaning, would a vehicle ever get better mpg at a higher speed than a lower one? I think yes, because I think I owned one. I imagine those situations are unique though.
I got 32 actual MPG in a 12A RX-7 crusing at 80mph. Mostly I just parked the throttle at the point just before the secondaries started to open, and that was the speed I ran at.
The funny part: This was with some really steep gears and short tires, so the little thing was humming along at 5000rpm or so. 75-80 was the sweet spot for that car, less speed made for running in a crappier part of the BSFC map.
I'm thinking that the carb happened to be running a bit lean there, and rotaries don't care about lean if they are loaded enough. I also did some tinkering with the distributor and I think I had the mechanical advance locked out and base timing set to 22 degrees, and the trailing was way advanced and I was only running trailing vacuum, so there would have been a lot of negative split at higher vacuum. Which also makes lean running more efficient.
Running negative split is 90% of why I want to go distributorless, as my current distributor setup can only run zero split and that's that.
Pretty much any t56 car gets better mpg at higher speeds. All of them arr big torquey motors with a super long 6th gear.
So you could make a pretty large change in cruising speed, like 70 to 80 with a small change in rpm.
Both my camaro and vette, always seem to get the best mpg at or above 80
Vigo wrote:Interesting. Glad to see innovation like this.It's not really innovation. That's why it's a double edged sword to me. Glad someone's doing it, aggravated that it took so long. There is no single thing outlined in that article or video that needed any explaining to me. It was all pretty intuitive and obvious. It mostly makes me think that the only reason this got posted in 2017 and not 2007 is that there was finally the right mixture of incentives to just put the time in and implement things that were always pretty certain to work. I'll elect not to go on a rant about under-regulation... this time. Anyway, in a world full of stupidity and bad news i'll take the good where i can get it and just hope the rest of the OEMs implement similarly in the near future.
The aggravating part is the tiny problem that the entire industry, other than a small group from Toyota, pretty much abandoned the optimization of the basic gas engine. It's not as if Toyota didn't sway away, too- just that a group of dedicated engineers went out on their own to do this.
Now that I think about it- the team of engine designers for the hybrid program likely did this. We have one, too. But they did make the leap from a hybrid motor (which is a little different than a normal motor, since the duty cycle is more controlled) to a conventional powertrain.
This is going to shake things up for a few years. Maybe get some of the marginal tech that doesn't add much out of the system.
The innovative part is that they kept doing the work. Which sucks for the rest of the industry.
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