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 have tried to locate a BSFC graph for my engine:

    Dodge Dakota 4x4 V6 3.9L 275HP (1997)

    but as of yet I have been unable to find one. I have reviewed the one that has been floating around on the forums here but that is for a small higher reving engine. I have been doing my best to pulse with about 63% LOD and keeping it under 2000 revs but it don't seem to be giving the results that I am expecting.

    Can any one help me???? Please:confused:
  2. Damionk

    Damionk DWL Lover

    BSFC charts hard very hard to come by, you may not be able to find one at all. I am still working on my P&G, but most here agree that a LOD of 75-85 seems to be the ideal range for most engines. You just have to find that sweet spot.
  3. JusBringIt

    JusBringIt Be Inspired

    Your tps should be increased as your speed increases. Do that while staying in the highest gear possible.

    If that doesn't work, I'd try to find a clinic. P & g shouldn't be too difficult.
  4. Die2self

    Die2self Saving more by using less!

    Thanks guys

    I have usually been decreasing the TPS as speed increases as tourqe and HP increase. I will try and start at 30-35 and increase 1-2 TPS with increaseing speed. i will try and remember to come back and post any updates.;)

    bringit, are you offering a clinic?? I would love if there were a clinica around the 4 states area as I have noticed there about a dozen or more poeple around the area here on the map.:D
  5. JusBringIt

    JusBringIt Be Inspired

    If you decrease tps as speed increases you are having a lot of losses due to slipping, which I'm sure is what the issue is if you are using P & G.

    As for clinics, I'm up for giving them, however I'm in the Capital region area on the east coast which is quite a ways away from where you are ;).
  6. Right Lane Cruiser

    Right Lane Cruiser Penguin of Notagascar

    Jason has a MT truck so there is no slipping to worry about. On the other hand, easing up on the pedal is taking the vehicle out of the ideal load range -- that's why the P&G isn't working.

    Jason, swap around your method and start out with a lighter pedal (lower TPS) and increase it as you accelerate (higher TPS). Watch your LOD value and try to keep that about the same as you accelerate.
  7. JusBringIt

    JusBringIt Be Inspired

    oh heheh...I didn't see where that was posted...oops:p.
  8. PaleMelanesian

    PaleMelanesian Beat the System Staff Member

    I agree. Lower tps at low rpm, higher tps at higher rpm. Aim for equal LOD the whole time.
  9. Die2self

    Die2self Saving more by using less!

    Ok, thanks for the info, I tried it on the way home, but it didn't feel much different (21.0 over 13.1). I will keep trying it for next week and see if I can narrow in on the LOD and increasing the trottle.

    I went from TPS 35-44 (which is getting to 100% TSP45), I guess it just seems odd to me to speed up the faster I go :eek: but so be it, I will keep the post going with information.

    Thanks again guys. ;)

    MT in the sigs ;)
  10. Die2self

    Die2self Saving more by using less!

    what V6 do you have in your avenger bringit? Is it basically the same one as mine or something totally only for the car side of dodge?
  11. visionseeming

    visionseeming Well-Known Member

    I'm going to reply for him only because I looked up his car a while ago.:p It has a P.O.S. Mitsubishi 6G73 2.5 L V-6 mill, mated with a pretty decent Chrysler 41TE 4 Speed tranny.
  12. Die2self

    Die2self Saving more by using less!

    I was hoping that the engine might be similar to see if we could compair numbers but since it is not, I guess it is back to my cold dark cave for me :0b
  13. Die2self

    Die2self Saving more by using less!

    On the commute this morning I tried to keep the LOD at around 30 to 35, which is about 75% of the LOD, but I noticed that when I tried to keep a steady foot on the accelerator, the LOD values would go up as the speed increased. Is this normal? I don't know if this technique will transfer from a car engine to a truck engine that was built for torque. I will keep an eye on it and contiue with the trials
  14. Taliesin

    Taliesin Well-Known Member

    Are a couple of those "LOD" supposed to be TPS or something else?
  15. JusBringIt

    JusBringIt Be Inspired

    The specific x-mission in my car is tha A-604 (just one of the 41te). The transmission could have been a bit better though. I would have preferred to go into OD at 25mph, but it's set to 37-38mph :(. That means I rev EXTREMELY high (2400rpm) to get it to upshift.

    The engine is too heavy for the power that it produces, coupled with poor mileage ratings. Chrysler's 2.0l was better.
  16. Die2self

    Die2self Saving more by using less!

    No they were LOD values. I am still trying to keep the TPS around 30-35 and that is right about 28-30 for LOD on Level ground. When LOD gets to about 33-36 TPS is up around 40TSP.

    My TSP seems very short were 12 is idle and 48 is WOT. Is any one elses that narrow?
  17. JusBringIt

    JusBringIt Be Inspired

    I think he was talking about this
  18. Die2self

    Die2self Saving more by using less!

    I hear that Ricardo, the 3.9L would seem to be under producting power from the size that it has. It always seems to be out of breath. That is why I got an Airaid intake for it, which does help out with low end power and torque which is where i want it now :D

    I likes to cruise between 45-55 with out much effort, but getting it up to that is just a big hit on the tank. That is why I like to keep it on the highway more than in town.
  19. Die2self

    Die2self Saving more by using less!

    That was meaning that LOD at 33 is 75% of the max 44-45 for WOT or 100%. Does that help

    LOD Value Percentage
    4 0
    33 75
    44 100

    It just seems odd that the LOD and TSP are so narrow on my truck.
  20. Taliesin

    Taliesin Well-Known Member

    LOD is (or should be) a percentage value that varies from X (a variable depending on the vehicle) at idle to 100 at WOT.

    If your LOD never goes above 44-45, something is wrong.

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