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Tuning my 347 with rear mount turbo

Discussion in 'EEC V' started by Dono, January 29, 2016.

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    1. Dono

      Dono V8 Limited turbo and retired SC 4.0 OHV Elite Explorer

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      I'm getting closer. I still get an exhaust smell in the truck with the roof open sometimes, but my eye's don't burn and water anymore. That's a good thing. I can work on slight modifications of exhaust pipe placement and see what works better.

      Tim came by last weekend, and showed off without even knowing it. As he was leaving, he jumped in his truck, and it started right up. Imagine that? I was/probably am still struggling with that. I was ready to try different injectors, thinking I must have one leaking.

      I found that playing with the cold start fuel table really makes a difference on where the crank fuel pulse width needs to be. Makes sense, screw with one thing and you throw other things off. Laws of nature. I hope I finally nailed it though. Today it actually started every time without having to touch the gas. For whatever reason, my combination is way more finicky about starting (or adjusting for starting) than I think is normal so a vehicle that has had the crap modified out of it.

      Anyway, I just might have found the magic. I'm actually pretty excited about it. One of my goals has been to make this truck completely drive-able with no quirks (other than the fact it has a unmistakable sound to it, in the cab it sounds pretty quiet).

      I'm still playing with timing as I want to just see the J&S sensor activating slightly when I lean on the gas. This tells me that its probably only modifying the timing on a couple of cylinders, which means best power. Pulls super hard from 3000rpm and up.
      I have no warning from the sensor at all below 3000 rpm, so I'm slowly adding at 2500 and 3000rpm (under load with at least 0 vacuum so the brain is turned on). This tells me to add timing slowly. Its a process as I'm trying to get as close to the raggedy edge as possible.
       
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    3. vroomzoomboom

      vroomzoomboom Elite Canuck STOCK SUCKS! Elite Explorer

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      for what ever reason, we have opposite problems. yours is warm start. mine is cold start. i have a slight surge when its cold for about the first min or so. think i am going to have to live with it.
       
    4. Dono

      Dono V8 Limited turbo and retired SC 4.0 OHV Elite Explorer

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      Here's my first thought, but it would probably only affect the first 15 seconds.

      upload_2017-9-1_11-57-59.png

      I know your idle integrator is set correctly, so that's not it.
      Maybe the base fuel table cold is adding too much, or too little fuel from 70 to 100 degrees at low (idle) load? We would have to play around with it and see if anything makes a difference.

      upload_2017-9-1_12-0-54.png
       
    5. Dono

      Dono V8 Limited turbo and retired SC 4.0 OHV Elite Explorer

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      Iv'e been struggling with taking out the thrust bearing in my motor, and am looking at all possibilities.
      What might be happening is that there is to much trans fluid line pressure pushing the torque converter in to the flex plate, and in turn the pressure pushes the crank hard in to the bearing, wiping it out.

      This includes fixing up some trans cooler lines that were cut, and returning them to factory. There was a couple of tight L connectors that might have been restricting flow. I also have a new torque converter with a billet front cover on it to take the possibility of ballooning out of the picture.

      This led me down a road also as to the need to check trans line pressure. I obviously can't do this until the motor is back in, but I still want to see if I can reduce the pressure using tuning. Decipha wrote this article (Thanks Decipha!) Transmission / EFIDynoTuning and it specifically talks about trans line pressure being affected by the torque table.
      Here's a quote from Decipha that made me take a second look:

      "Dynamic TV pressure is calculated by engine torque, the ecu uses the current airmass from the MAF Sensor to calculate engine torque. That value is compared to the engine
      torque table FN1615A - Engine Torque Table, which is scaled by Load and RPM, if the actual torque is less than this table then you get excess pressure,
      If the actual torque is greater than this table then you get less pressure. This table must be manually dialed in by the tuner. "

      Now, Decipha does not tune SCT, but the ecm still has the same programming, no matter what method you use to tune it. This made me look in my current tune in the SCT Pro Racer Package. There are some area's I had not really looked at, and had purchased a tune from Don Lasota to see if he could help me with some issues.

      Here's the description of the Torque Table in the SCT software:
      upload_2018-7-26_8-36-45.png


      The following are 3 screen shots of the factory torque table, what Don Lasota has mine set to, and the 3rd is the torque table I am thinking of starting with when the motor goes back in.

      Factory
      upload_2018-7-26_8-38-14.png

      Don Lasota Settings
      upload_2018-7-26_8-38-59.png

      My "Best Guess" wild arsed guess settings:
      upload_2018-7-26_8-39-46.png

      @4pointslow is willing to put the effort in to helping me with this and let me know with some fact (Rather than my guessing) if I'm on the right track, or lost in some field. There is really no way to completely understand some of this stuff as a pure hobbyist. Taking out these thrust bearings is getting really expensive, so its worth looking at everything.
       
      Last edited: July 26, 2018
    6. 2000StreetRod

      2000StreetRod Staff Member Moderator Elite Explorer

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      Interesting. As you have determined, PCM calculated load is an important variable. That is the reason I refused to alter the MAF sensor function to achieve the desired AFR.
       
    7. 4pointslow

      4pointslow Explorer Torture Tester Elite Explorer

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      The best way to dial in that table might be to get the whole truck on a dyno and see what real torque output is at each rpm and load range.
      Don Lasota probably would have used a table that was generated by him and others who did the work to increase torque of the engine, and then ran it on the dyno themselves to see where it all was and then the table was saved as an example to get you close as possible without running your vehicle on the dyno.
      If Don himself wasn't involved, it probably would have been someone at SCT.

      Keep in mind that if your vehicle was not modified in the exact way then you would have to adjust for the differences (On dyno), to be exact.

      The Factory load table you posted goes up to 1.250, what is your datalogging showing for max load at WOT?
       
    8. Dono

      Dono V8 Limited turbo and retired SC 4.0 OHV Elite Explorer

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      for max load at wot, the last datalog was about 1.09
       
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    9. Dono

      Dono V8 Limited turbo and retired SC 4.0 OHV Elite Explorer

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      ok, I hope I can actually get to the dyno stages without taking out the thrust again. lol.
      I also think for the time being I'll stick with those wild arsed settings that are lower than Don Lasota's to bring the pressure down some.

      Thanks for helping with whats required to actually know the right way to adjust this table.
       
      Last edited: July 26, 2018
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