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Thread: 6-71 blown Hemi going full lean on throttle tip-in

  1. #1
    Tuner Mattechperf's Avatar
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    6-71 blown Hemi going full lean on throttle tip-in

    I've driven myself bonkers trying to figure this out and I'm sure its something obvious right on front of me.
    First, this a 2006 300c SRT8. It's now a 6-71 blown 398ci with a progressive, dual Hellcat throttle body setup on top. The linkage to the 2nd TB is mechanical on a progressive setup that doesn't start until about 33% of the primary TB opening.
    2bar MAP, 80lb Ford injectors, boost referenced FPR set at 43PSI. Cam is .598/.598 and 248/252 @ .050.

    I've settled the idle AFR out and dropped the base timing to 14 around the idle areas to start. I haven't had drive time yet to work on the VE or spark tables yet. This is all in open loop. Fuel pressure doesn't drop during this problem.

    When I give any amount of throttle quickly, it goes full lean. Slow raise of the pedal will get the RPMs up, but a good rev just makes it lean pop hard.
    In the attached log, the instance takes place around 07:11:41.257 to 41.267
    Huge thanks in advance for any help. I can't tell you how much I've already learned from the great people around here.

    A-Bom_LSFO_007d_01_Tip in Lean Out.hpl
    MattL 2006 300c ABom_LSFO_007d.hpt

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  3. #3
    Tuner Mattechperf's Avatar
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    Quote Originally Posted by spoolboy View Post
    Thanks! That's some super helpful info.
    I didn't notice how much my TPS was ramping up compared to my pedal input.
    Pedal goes .93v-2.10v and TPS goes .56v-3.33v,

    I found my FA WOT Pedal (WOT Pedal Thresh) which is set at 3.1961. But, it must be something with the Pedal V to TPS V relationship.
    I'm not sure if this is the TB Airflow tables or another voltage to voltage relations ship table I'm not seeing somewhere.

    Capture1.JPG

  4. #4
    I?m just learning myself, but I think with the positive displacement blower you want power enrichment early, but a slower throttle opening. Or maybe not. Still learning. Maybe look at the Hellcat tunes and see what?s going on there? I know they run a stoich ratio of 13.X:1 instead of the 14.x you would normally expect.

  5. #5
    Woah, I hadn't looked at your tune before when I commented.

    You definitely want to fill this table in where the 0's are with some stuff. And the numbers at the bottom are very small/lean. Probably start with filling the whole table with .0153 and lean it out from there? That should get you a requested 12:1 AFR any time you are in power enrich.

    powerenrich.jpg

    Also, under airflow general tab, it looks like you have mixed data from 2 and 3 bar map sensors?

    Take a look under characteristics and pressure ratio. Characteristics look like 2 bar and pressure ratio is 3 bar? What sensor do you have on there?

    Again, I'm just learning too, but I feel like that stuff is correct.

    Anybody else care to chime in?
    Last edited by spoolboy; 5 Days Ago at 11:00 PM.

  6. #6
    I also think these tables both need to be scaled the same. Max pratio of 1.5 on one and 1.8 on the other.vepratio.jpg

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    Tuner Mattechperf's Avatar
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    Quote Originally Posted by spoolboy View Post
    Woah, I hadn't looked at your tune before when I commented.

    You definitely want to fill this table in where the 0's are with some stuff. And the numbers at the bottom are very small/lean. Probably start with filling the whole table with .0153 and lean it out from there? That should get you a requested 12:1 AFR any time you are in power enrich.

    powerenrich.jpg

    Also, under airflow general tab, it looks like you have mixed data from 2 and 3 bar map sensors?

    Take a look under characteristics and pressure ratio. Characteristics look like 2 bar and pressure ratio is 3 bar? What sensor do you have on there?

    Again, I'm just learning too, but I feel like that stuff is correct.

    Anybody else care to chime in?
    See? This is why another good eye is so helpful. I've changed things around so much, I've just overlooked these things.
    The PE Table I didn't think would be an issue until I actually started driving. But, since something is commanding the throttle to crank open all of a sudden, it's definitely hitting that table.
    I've populated that table accordingly now.

    Now, the MAP I'm using is a Neon SRT4 2-bar (5033224AB) and I used the data straight from a 2004 SRT4 file. Although, the PRatio Max Turbo I had set at 3.00 instead of the 0.950 shown in the SRT4 file.
    Also, in the Engine Diag section, I have the same MAP voltage numbers, but my Max MAP is 300.0 kPa and Min MAP is 2.0 kPa while the stock SRT4 shows Max MAP as 227.0 kPa and Min MAP as 4.8 kPa.

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    Quote Originally Posted by spoolboy View Post
    I also think these tables both need to be scaled the same. Max pratio of 1.5 on one and 1.8 on the other.vepratio.jpg
    Again, good catch. And you're right. Thanks!

  9. #9
    What does your MAP signal look like at idle? Voltage and pressure.

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    Quote Originally Posted by spoolboy View Post
    What does your MAP signal look like at idle? Voltage and pressure.
    I don't have the MAP voltage logged, but at a 1100 RPM idle, MAP is 59 kPa. That seems consistent with the 10-11 inHg of vacuum I've seen on my mechanical gauge.
    I'll have to log the voltage later today.

  11. #11
    How big is the cam?

  12. #12
    inhg.jpg

    I changed the units on your scanner file and screen shotted it.

  13. #13
    Please take my responses with a grain of salt - just started with HP Tuners and ECU tuning in general.

    Been playing with cars a long time, but not exactly like this. I could be leading you astray.

    Anybody else care to refute?

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    Tuner Mattechperf's Avatar
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    Quote Originally Posted by spoolboy View Post
    How big is the cam?
    Cam is .588/.588 248/252 @ .050 114 LSA


    Quote Originally Posted by spoolboy View Post
    I changed the units on your scanner file and screen shotted it.
    I had to create a math for the vacuum reading since you have to subtract one atmosphere (14.14 PSI at my elevation in Phoenix).
    So, 19.5-28.8-ish gets you about 9.3 inches of vacuum.

    Quote Originally Posted by spoolboy View Post
    Please take my responses with a grain of salt
    I absolutely appreciate the effort. We're all learning something at any given time and us working through some of this will hopefully help someone else later.

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    Quote Originally Posted by Mattechperf View Post
    I don't have the MAP voltage logged, but at a 1100 RPM idle, MAP is 59 kPa. That seems consistent with the 10-11 inHg of vacuum I've seen on my mechanical gauge.
    I'll have to log the voltage later today.
    I added MAP Volts to the Scanner and logged some run time. With the idle around 850 RPM, the MAP is around 67 kPa.
    I dumped the log into Excel and, with a range of 26 kPa to 111 kPa, I found an average of 46.20 kPa/V.
    My current settings are:
    MAP Sensor Linear - 46.38 kpa
    MAP Sensor Offset - 4.80 kPa
    MAP Sensor Offset - 0.10 V

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    Seems to me you just need to add some decent chunks of percentages to your VE tables or your injector data is just way off. What injectors are in this? And what type of fuel system (return style with rising rate regulator?).

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    Quote Originally Posted by 06300CSRT8 View Post
    Seems to me you just need to add some decent chunks of percentages to your VE tables or your injector data is just way off. What injectors are in this? And what type of fuel system (return style with rising rate regulator?).
    Thanks for the input 06300CSRT8. FYI, I've learned TONS from your posts all over this forum. So, thanks for that.
    Now, I'm using the Ford 80# injectors. The fueling is a boost referenced return style set at 43.50 PSI. I built the fuel tables (PW vs Mass, Mass vs PW, and PW Offset) directly from the Ford datasheet and interpolated the numbers for this fuel pressure.
    The injector data came right from a spreadsheet built by Dave Steck of DSX Tuning.

    When I first had the VE tables in there, it seemed like it was just DUMPING fuel in. So, I just took it down by 10% until the idle wideband AFR matched the Commanded AFR.
    What bothers me is the rate of throttle opening vs pedal input seems off the charts. In the attached picture, you can see as the Pedal input increases, the Commanded throttle % just skyrockets.

    I'm totally missing something, so I appreciate the help.

    TooMuchTPS.jpg
    Last edited by Mattechperf; 2 Days Ago at 10:56 AM.

  18. #18
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    Its following exactly to your Engine->Torque Management->Driver Demand -> Power % request which maps TPS voltage versus power output.

    I would cut the 0.9, 1.5, and 2.0 fields by 30% and see how you like it. Go too far and itll feel dead.

  19. #19
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    But i don't think its the cause of your lean condition. Any check engine codes? What you describe sounds like crank sensor error (cuts out fuel etc anything about like 3000rpms in drive. Also be aware your in neutral and park rev limiter is set to 5000 in your tune.

  20. #20
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    Oh and just for sanity sake, Engine->Torque Management->Driver Demand -> Expected Pedal should be a mirror image of the Power % Request table. If you look, the column headings of the Expected Pedal table are the actual values going across the Power % Request table (or it should be), and the values in the graph of the Expected Pedal should be the column heads from the Power % Request table.