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Thread: 2019 mustang GT roush 2650 closing throttle

  1. #1
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    2019 mustang GT roush 2650 closing throttle

    So, this is basically a stock 2019 ford mustang gt on a roush supercharger, it has the stock roush tune except i leaned it a bit, removed the CAT and turned off the cat overtemp protection, it put 590whp on the dyno on 93 octane, the thing is its closing the throttle on higher gears, i tough maybe it was only doing it on the dyno but it also did it on the street.

    Log
    dyno5.hpl

    tune
    roush1 93oct final.hpt

    any ideas on how to cure this?

  2. #2
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    bigger injectors u hit max limit

  3. #3
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    not that, check on the other part of the log when i run it thru the gears

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    You are hitting Combustion Stab.-limit and injector limit.
    I attached a modified file for you to test.
    roush1 93oct final_test.hpt

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    Back from more testing, still doing the same thing, tested taking driver demand 15% higher and didn't change anything, also tried eliminating the throttle airlimit reductions with no success, there has been no change in the behavior except that now im not getting any advance from the knock sensors, i dont even know where else to look so ill be happy to listen to any idea.

    heres the last log and tune
    roush1 93oct final3.hpt
    street3.hpl

    You would have though that roush's tune would be good for a stock car and end up finding out is garbage.
    Last edited by mJolnir; 02-16-2020 at 03:20 PM.

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    Read above. - u are out of injector and the computer is closing throttle body too save your motor
    Keep reving motor and kiss motor goodbye

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    What are the signs of it running out of fuel?

    "insufficient fuel flow" msg i get is above 7500 and im commanding the gears at 7000-7200, fuel pressures seem to keep up and fueling is folllowing commanded.

    when it was commanding fueling in the 0.72 and going into cat overtemp it was indeed out of fuel.

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    I was under the impression the MU52 can support 700RW?

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    I agree with the guys here, you need to be logging inj duty cycle. Inj pulsewidth etc. It definately is out of injector. Its not commanding op, that i can see, its staying in closed loop, granted its showing fueling on the factory widebands, however its only commanding .9lambda. You are fighting fueling( or lack there of) and most likely torque settings. This motor will eat ring lands if left like it is
    Michael Bray
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    Quote Originally Posted by mbray01 View Post
    I agree with the guys here, you need to be logging inj duty cycle. Inj pulsewidth etc. It definately is out of injector. Its not commanding op, that i can see, its staying in closed loop, granted its showing fueling on the factory widebands, however its only commanding .9 lambda. You are fighting fueling( or lack there of) and most likely torque settings. This motor will eat ring lands if left like it is
    In the log above it is logging injector pulse width, you can see how it goes down when the throttle starts closing, wb1 and wb2 is showing 0.79-0.80, fuel trims are around -7% and fuel source says "Power enrichment", i don't believe the engine is in any danger, but it is annoying that the car will simply stop accelerating.

    Remember these engines don't go into open loop like the chevys or the older 3v stuff that had narrowbands, they stay in closed loop and let the widebands do corrections even when WOT, that's what makes it possible for guys like Lund to tune any mustang remotely

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    So what’s the end result, it seems the car shuts the TB, I believe as IAT2 rise? I’m curious how to fix this safety on the injectors that the kit came with? Can u tune a 18 2650 Roush for 93 octane on the pulley that it comes with safety?

    I was thinking a BAP, run a bigger pulley (lower boost to 10psi) and retune it?

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    Quote Originally Posted by Stymee View Post
    So what?s the end result, it seems the car shuts the TB, I believe as IAT2 rise? I?m curious how to fix this safety on the injectors that the kit came with? Can u tune a 18 2650 Roush for 93 octane on the pulley that it comes with safety?

    I was thinking a BAP, run a bigger pulley (lower boost to 10psi) and retune it?
    With the roush stock tune the car would output only 470whp, it went into COT and that would make it throw a "insufficient fuel flow" protection, we removed the cats and its protections as we dont have any laws that prohibit doing it, with that it got better, but still would get insufficient fuel flow, so instead of targeting 0.73 lambda at WOT i targeted 0.80, that brought the horsepower from 510whp up to 560whp, low side fuel pressure was falling so i added voltage to the pumps to stop it from falling and thats how i ended at 590whp.

    For a single gear pull on the dyno it was all ok, but when i tested the car on the road i noticed that it would close the throttle after 3rd gear down to 60%. The owner bought the car with the roush package and of course when he called them to say the car only had 470whp they blamed the fuel, then they blamed him for removing the cats and last but not least they blamed me for "tampering" with their program.

    BAP could be an option but the customer now is just disappointed and does not want to spend any more money on the car and will just sell it.

    Here is roush stock tune in case you where interested.
    roush0.hpt
    Last edited by mJolnir; 03-20-2020 at 10:28 PM.

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    I was under the impression HIGH IAT2 are the reason why the Roush tune closes the TB?

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    Ok can one of of u answer me this?

    On these dyno runs, did u shut down DI and only ran off the 47lb Injectors? That would be kinda dumb if u did, rail pressure would absolutely drop if u did?

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    Quote Originally Posted by Stymee View Post
    Ok can one of of u answer me this?

    On these dyno runs, did u shut down DI and only ran off the 47lb Injectors? That would be kinda dumb if u did, rail pressure would absolutely drop if u did?
    i did not turn DI off, but i did test changing the blend to 30%DI/70%PI and low side fuel pressure fell even after i brought the pump voltage up

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    Looks like we’re gonna need a BAP to fix this but have u seen the TB closing because of IAT2 climbing too?

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    Advanced Tuner veeefour's Avatar
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    Quote Originally Posted by Stymee View Post
    I was under the impression HIGH IAT2 are the reason why the Roush tune closes the TB?
    Those latest Roush blowers...lame TB location, poor cooling that leads to overheating IAT and chopping power...

    Get Whipple or Edelbrock.

  18. #18
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    OP,

    2019 and out of fuel at 590rwhp?LOL You are not hitting your fuel limit cuz your system is 800rwhp ready from factory - you are hitting LOAD and TORQUE limits.

  19. #19
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    Quote Originally Posted by mjolnir View Post
    remember these engines don't go into open loop like the chevys or the older 3v stuff that had narrowbands, they stay in closed loop and let the widebands do corrections even when wot, that's what makes it possible for guys like lund to tune any mustang remotely
    i see your logging fuel system status, which remains closed loop. I assumed fuel source, thats what should be logged, as it will determine if it is actually going into power enrichment, or being fuel(torque) limited
    fuel source should display (ol) power demand enrich, if its not being limited. When its only commanding .9lambda, i assume its not, as it should be showing a commanded .8lambda
    Michael Bray
    Rusty Knuckle Garage
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    Custom Car Fabrication, Customization, High Performance.
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  20. #20
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    VPerformance, Instead of telling us how bad the Roush is how bout answering my my question?

    I can drop IAT2 with an ice tank at the track, so that’s solved. What about the tuning, I assume the Roush cal is so tame it’s just not gonna run a good number until u actually modify they tune?

    PBD/VMP went 10.4@130+ with the 18+ kit
    It runs if tuned correctly