Quote:
Originally Posted by Porsche
I note that the coolant temperature typically begins far higher than ambient temperature. I assume that's not residual heat remaining from the previous drive, so I'm guessing it's because the engine has been on and idling before you drive off. The graphs seem to begin when you drive off, not(?) when you first start the engine.
|
Most of the graphs actually start within less than 30 seconds of engine start, so make of it what you will. The only graph that has a late start was the one from Oct 4th, because I had to restart the car twice before the bluetooth would connect so you're actually looking at a third "start engine and wait for revs to drop" in a row there (I know, terrible for the engine... ugh). In every other graph you can see the vehicle speed starting out at zero for about 15 to 30 seconds which is me waiting for the revs to drop and we all know that that usually takes about 30 to 45 seconds.
Once the revs drop I almost immediately head out because I don't wanna be late for work and I know I'm gonna have to granny it on the way out so every second counts. So, knowing that the zero-speed section at the beginning represents me waiting for the rev drop one can come up with an approximate timeline of how far after engine start any given graph starts. I can't conclusively say that it's NOT residual heat, but I also think that maybe the water in this car gets hot SUPER FAST.
Quote:
Originally Posted by Porsche
Do I guess correctly that you live within about 2 minutes drive of the Interstate?
On these graphs, you're accelerating briskly up to 75 mph within less than 3 minutes from first driving off.
|
Yep, very close.
That load measurement is wacky, I'm actually REALLY babying the car even on the onramp, like never more than 20% throttle (if that) until I get to the offramp for my work. This car just holds the corners so tight that I'm able to carry the momentum from the surface streets all the way through the loop so I hit the straight part of the ramp at 45 MPH or more. Even while grannying it this car is (relatively) quick, very often smooth driving will get you out of a turn just as fast (or faster) than brute force.
Quote:
Originally Posted by Porsche
I wonder if the time to bring the oil to proper operating temperature would be extended were one to spend the first 10-15 minutes just gently driving around town at no more than, say, 40 mph? My guess is that it would not take significantly longer to bring the oil up to temp. But, I don't know.
Perhaps you'd care to log that and share that, too. (It is interesting what you can do with that tool.)
|
So, I take the freeway route because I feel that it is a gentler warm up than going through town. If I take the surface streets all the way to work it's actually a lot faster (only 8 minutes) but it is all stopsigns and stoplights on the way... so it would just be a long series of "launch car, get to second, bump into third, oops time to stop" and the car would barely even spend any time in third gear. The blocks in my town are VERY short so all that repetitive stop and go would not be very nice to the car.
There have been a few days where I was gonna be late to work if I took the freeway route since that takes about 15 minutes but the town route only takes 8. I didn't have the logs running but I unscientifically concluded that the car gets up to temp just as fast if not faster based on how quickly the needle hits that second mark where it always settles and how quickly the heater starts blowing hot air. I mean, it makes sense that all those repetitive launches would put quite a load on the engine considering Newton's first law.
I will get a log of that alternate route ASAP, probably Monday if I remember.
Quote:
Originally Posted by Porsche
As you noted, the Engine Load % is interesting. I wonder what parameters they're measuring? Do you suppose the software may regard very low rpm + large throttle opening as lugging and show that as high load percent? Just guessing, trying to account for what you've seen as odd graph lines for that measure.
|
Yeah I have kinda come to the same conclusion... but I
never lug it so I dunno. My best guess is that it has very little to do with ACTUAL engine load, but instead is some super-complicated mathy formula that the ECU is doing based on vehicle speed, engine RPM, MAF readings, etc and it's using this here "engine load" number as an input to another formula for determining timings and AFR and whatnot. I don't log timing or AFR but I do have live graphs of them running on Torque and they both seem to have a very close relationship to engine load. Keep in mind that I only log data points every 5 seconds as well, so there could be some hysteresis induced errors in the readings and we might be completely missing the whole picture that we might see if I could log 10 times a second or something.
I mean, there's no way that a less than 20% throttle slow climb to 30 MPH could actually represent "75% engine load" (look at about the one minute mark on most of the charts to see the particular moment I'm referring to). If THAT was 75% engine load then what am I doing when the car is hot and I hard launch, chirp the tires, and am at 30 in the blink of an eye... 250%?
Quote:
Originally Posted by Porsche
Finally, is there anything I might do for you in return for your kindness? Anything about our wonderful cars or about driving, perhaps, that I could share with you? Any questions at all about, oh, handbrake starts on hills, or heel-and-toe, etc? (I don't know your age or experience. Me? I'm old and may have learned a useful thing or two over the years.  ) |
Awe thank you so much, you're too kind. The truth of the matter is that I have SOOOOOOOO much fun geeking out over all this stuff that no thanks is necessary at all. I'm an EE and doing R&D stuff is my hobby, hence why I was already logging all these things and really just needed to click a few buttons in Excel to get those graphs made up... no problem at all, pure fun! The fact OTHER people would even be interested in my results is the best reward of all!
Haha, I'm self-described as old but physically I'm not. Married, graduated, career'd, shaking fist at hooligan teens, etc... I check all the boxes for being "old" despite still looking like a kid to most people twice my age. Go buy some cool dude a beer and chew his ear off about car stuff and we'll call it even
