BSFC help needed

Discussion in '4x4's, SUV's and P/U Trucks' started by Die2self, Apr 17, 2009.

  1. Die2self

    Die2self Saving more by using less!

    I will put that up on the SG screen and see what the LOOP is doing on the way home. And I have been trying to Glide longer (which is getting easier with the warmer temps):D. If there is no one coming up for a awhile and I am pulsing up to 60 I will let it glide (NICE-on) to 40 before I pick it back up. But there are a few spots on the highway interchange that I don't want to be caught doing 40 up hill. So, I try and keep it around 55 through the interchange as to not impead traffic in that area.

    I found this:
    [​IMG]

    Now if i can get the lower graph I would have the BSFC i was looking for. What is the lower graph line, gas consumption?
     
  2. PaleMelanesian

    PaleMelanesian Beat the System Staff Member

    From that chart, peak torque is at 3200 rpm. You don't want to be going that high, though. The step at 2000 looks like a good spot to aim for. Mine is similar, with a lower peak around 2000 and another peak in the 3-4k range.
     
  3. Die2self

    Die2self Saving more by using less!

    That is what have been shooting for in all my shifting points is 1800-2000. :0)

    I guess if I wanted a Fuel consumtion graph I would have to do it with the SG to GPH (Gal/hour) and get a number for at least every 500 or 1000 RPM point. Is that what you would do? Or do you think it is not worth it and just stick with what we know now.

    Shift at >2000K
    Pulses
    TPS = 35-42 (as you stated not to really go higher andrew)
    MAP = 12.5-13.1 or so (depending on the data from tonight with LOOP readings.
    Then glide as long as possible (45-40 depending on traffic);)
     
  4. PaleMelanesian

    PaleMelanesian Beat the System Staff Member

    Sounds like a good starting point. You'll have to adjust it for hills and traffic, like you mentioned above.

    I've considered mapping out my BSFC, but it'll take a lot of work. You really need to do multiple runs at varying tps points as well.
     
  5. Die2self

    Die2self Saving more by using less!

    :eek: not sure I have that much time, atleast not right now.

    Ok sorry for being late tonight, we just got home from services and put the kidos to bed.

    Alright, it was a nice day to test as it was 84 and no wind.:D (I still got 22.4 (think that had mainly to do with the weather and no wind) pulling into the driveway, I had over 23 until I hit town.:eyebrow:)

    After getting all the displays on the SG and getting on the highway and got to my first spot to P&G I started at 45 MPH in 5th and put the Trottle down:

    TPS = 35 (normally what I was using)
    MAP = 12.6
    LOOP - Closed

    started increasing the pulse until I got to 60 MPH
    TSP = 40 (new possition)
    MAP = 13.6
    LOOP - closed

    TSP = 45
    MAP = 13.8
    LOOP - closed

    TSP = 50
    MAP = 14.1
    LOOP = closed

    I noticed after a few pulses that the LOOP value would change when TSP was over about 55 to Open, but this was about the time I reached my 60 limit. I would not normally push the trottle from 35 up to 55 on a pulse. I usully use 35-45 or 48 max.

    What do you think?

    I think I will try to only do the new pulses and longer gluides tomorrow to see what happens, althought we are suppose to have strong winds from the South tomorrow (good for the trip to work, but head wind on the way home).
     
  6. Taliesin

    Taliesin Well-Known Member

    It looks like all of your pulses were just after a bump start?

    It takes the engine a few seconds to go from closed loop to open loop operations after a restart.

    That's what you were noticing the few times it did switch to open (the Ranger often switches to open right at the end of some of my pulses).
     
    Last edited: Apr 23, 2009
  7. Die2self

    Die2self Saving more by using less!

    I am not typically using NICE-Off glides. I am only doing that at this time to coast to lights that have just turned red and they will be a few minutes. I got to engine braking until I am in open loop, and then turn the engine off as it will then read 9999 when it wakes back up instead of the milage that it was when I turned it off.

    I mainly am still NICE-on gliding, because I have noticed after I bump start the ICE must think that it is cold again because the idle RPMs stay above 1100 instead of the 750 when warm. This is also why I try not to get caught at a light where I have to shut down because it does the same thing if I have to sit there very long, so it kills any glide after the initial start from the light once up to speed.

    The only time I see it in open loop is in engine braking, just starting the cold engine, and when I go from some stead state driving to gliding, the loop will go open and I will get 9999 on the iMPG read out and then it catches back up.

    I thought there were only 2 values in the SG for LOOP, Closed and Open.
     
  8. Taliesin

    Taliesin Well-Known Member

    Those are the only two. I edited my response aboe so it may be less confusing.

    I can't be sure if my memory is backwards, or if your truck is reporting backwards.

    Hmm... someone else will chime in on that, I am sure.
     
  9. PaleMelanesian

    PaleMelanesian Beat the System Staff Member

    It looks like you don't really have to worry about hitting the fuel enrichment of WOT, then. As long as it's in Closed Loop, you still have the computer adjusting the fuel mix. Some vehicles are much more eager to go to Open Loop and enrich the mix, but yours is not. I gave you a nearly and practically false alarm.
     
  10. Taliesin

    Taliesin Well-Known Member

    So my memory was backwards (or my truck is reporting backwards).

    If mine isn't in open loop for some other reason (just started) it won't go open loop until 95% LOD.

    Sounds like pulses with max TPS of 45 to 48 would be good (just don't let it hit that 55 or so when it goes open loop).
     
  11. Die2self

    Die2self Saving more by using less!

    right o, I will give a shot at these numbers for a few days to see what we get

    Thanks all for the help and sticking this out with me, especially Taleisin, Andrew, Ricardo
     
  12. PaleMelanesian

    PaleMelanesian Beat the System Staff Member

    Here's to your continued MPG improvement!
     
  13. Die2self

    Die2self Saving more by using less!

    even with the wind today 22.0 on the way home. I am still sure the warm weather is helping :D
     
  14. Die2self

    Die2self Saving more by using less!

    23.6 with the S wind @20-25 this morning.
     
  15. Die2self

    Die2self Saving more by using less!

    22.3 with a very stiff south wind at 25 Gusting to 35. I could feel that I made ground on the wind with more trottle (not going above 50) but since the wind was fighting me so much I was not able to gluide as long a normal.

    I have a nice 1/2 mile gluide that is down hill so I crest the hill at 45-40 (where the PSL changes to 35) and just NICE-on glide the bottom which nets about 1.5 MPG raise. I have to add a little Load to guide it up a little hill to sustain 35 and then coast it down and then up again to a light which I can see for a ways away so I know if I will have engine break a little of coast with engin off. It is a much better route than a 55 PSL road that crests the hill and is all down hill to a light you can see until you are over the hill and by that time there is not much you can do.
     

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