Advertisement

Much less torque after 6000-6200 rpm normal or issue?

Discussion in '2019-2020 Bullitt Mustang' started by npole, Aug 1, 2020.

  1. npole

    npole Well-Known Member

    Vehicle(s):
    Mustang Bullitt 2019
    Joined:
    Jul 12, 2020
    Location:
    Italy
    Posts:
    48
    Likes Received:
    7
    0   0   0
    As per title, now that I'm driving it by some days (and have collected already thousand kms!), today I'm starting to experience something that doesn't feel "normal". I don't remember if I've pushed it before, so I can't say if it's happening right now (or if it is the normality), I've tried to watch the videos online but I couldn't come to a conclusion.
    Basically after 6000-6200 rpm the torque goes down a lot, it pushes like crazy before then it start to "sleep", it takes a considerable amount of time (compared to the first 6000 rpm) to reach the limiter (7400) from 6000, to the point that i obtain a better performance by switching the upper gear at 6200 rpm than stay with the current gear until 7400.
    Obviously it is more noticeable in 3rd gear coz the acceleration is slower.
    I don't think this is normal (?), I have no errors, the car is perfect in every other aspect, the feel is like the electronic is limiting the power above those rpm (no it's not about the aid assists or such...), it does it in every gear and in every drive mode (I used to drive Sport+).
    What do you think it could be? Fuel pump? Catlyst? Does anyone had a similar issue?
     
  2. Schwerin

    Schwerin Well-Known Member

    Vehicle(s):
    2019 Mustang BULLITT
    Joined:
    Jan 31, 2018
    Location:
    Philly
    Posts:
    2,365
    Likes Received:
    1,097
    0   0   0
    Is this only when full throttle or when also just slowly reving it out?
     
  3. OP
    OP
    npole

    npole Well-Known Member

    Vehicle(s):
    Mustang Bullitt 2019
    Joined:
    Jul 12, 2020
    Location:
    Italy
    Posts:
    48
    Likes Received:
    7
    0   0   0
    Good question, I think I tried only full throttle (starting from different gears)... you thinking at the clutch protection?
     
  4. Schwerin

    Schwerin Well-Known Member

    Vehicle(s):
    2019 Mustang BULLITT
    Joined:
    Jan 31, 2018
    Location:
    Philly
    Posts:
    2,365
    Likes Received:
    1,097
    0   0   0
    Wondering more if its slipping, falty or wasnt installed properly.
     
  5. OP
    OP
    npole

    npole Well-Known Member

    Vehicle(s):
    Mustang Bullitt 2019
    Joined:
    Jul 12, 2020
    Location:
    Italy
    Posts:
    48
    Likes Received:
    7
    0   0   0
    Shouldn't I notice it at different rpms, not something that kicks in at that exact range (the car is perfect under that range).
    Also a slipping clutch shouldn't affect the traction? But the rpm should go up, even faster (unless the electronic sense the slippage by limiting the engine... as I mentioned above the clutch protection).
    I'm reading around that the shift point is when the torque start to fall, for a stock bullitt what range it should be? Maybe I'm just paranoid and it works as intended (as I don't have any other Mustang around here to test with...).
     
  6. Schwerin

    Schwerin Well-Known Member

    Vehicle(s):
    2019 Mustang BULLITT
    Joined:
    Jan 31, 2018
    Location:
    Philly
    Posts:
    2,365
    Likes Received:
    1,097
    0   0   0
    Those principals apply to any car.
     
  7. OP
    OP
    npole

    npole Well-Known Member

    Vehicle(s):
    Mustang Bullitt 2019
    Joined:
    Jul 12, 2020
    Location:
    Italy
    Posts:
    48
    Likes Received:
    7
    0   0   0
    I know, but looking at the videos online I believed that the stock max hp and torque in 3th and 4th were delivered well beyond 6200... (around 7k), that's why I'm confused to see it going down so early, but if that's true for every Bullitt out there, then I'm OK (hence this post). :)
     
  8. Schwerin

    Schwerin Well-Known Member

    Vehicle(s):
    2019 Mustang BULLITT
    Joined:
    Jan 31, 2018
    Location:
    Philly
    Posts:
    2,365
    Likes Received:
    1,097
    0   0   0
    There is a difference between TQ dropping off and the way you are describing it.
     
  9. OP
    OP
    npole

    npole Well-Known Member

    Vehicle(s):
    Mustang Bullitt 2019
    Joined:
    Jul 12, 2020
    Location:
    Italy
    Posts:
    48
    Likes Received:
    7
    0   0   0
    Do you mean I should experience no slow down going up to the limiter after 6200rpm (or so), like I have no problems going up to 6200? If that's true the optimal shifting point (best acceleration performance) up to 4th gear would be always to shift to the next gear right before the rpm limiter kicks in, but reading the other forum posts it seems that's not the case.

    As I mentioned in the first post, I feel the "push" up to around 6200, then the push is considerable less until 7400 rpm, and I obtain better performances by switching to the next gear at around 6200 than going above that. I just wanted to know if it's the same for anyone here, or if I have some sort of issue (which in that case, I'll book an appointment with the shop for more accurate tests... I don't wanna go there claiming to have an "issue" while discovering that this is perfectly normal :) ).
     
  10. K4fxd

    K4fxd Well-Known Member

    First Name:
    dan
    Vehicle(s):
    2017 gt
    Joined:
    Apr 2, 2020
    Location:
    NKY
    Posts:
    367
    Likes Received:
    97
    0   0   0
    According to Ford the bullet has peak HP at 7000 RPM, so no you should not feel it nose over at 6200.
     
  11. Burkey

    Burkey Well-Known Member

    Vehicle(s):
    2016 Mustang GT
    Joined:
    Feb 9, 2016
    Location:
    Australia
    Posts:
    3,493
    Likes Received:
    1,853
    Garage Profiles:
    1
    0   0   0
    Given that torque dictates the rate of acceleration for a given gear, what you’re saying seems fairly consistent with the dyno chart below.
    As always, peak acceleration occurs at peak torque and you can even see on the dyno chart that the torque is falling off fast enough that the Hp curve flattens significantly just after 6k.
    The point being that even though it’s fallen over and feels slower, the acceleration in the lower gear is still faster than the next gear because of the (approximately) 33% reduction in torque to the wheels with each shift on the 18+ MT82.

    If you have the time, you can input your data into the calculator below and work out the optimal shift point per gear.

    https://glennmessersmith.com/shiftpt.html


    7ECCB80C-21F9-4EB9-9305-FB18B6917BF7.jpeg
     
  12. Burkey

    Burkey Well-Known Member

    Vehicle(s):
    2016 Mustang GT
    Joined:
    Feb 9, 2016
    Location:
    Australia
    Posts:
    3,493
    Likes Received:
    1,853
    Garage Profiles:
    1
    0   0   0
    Hp yes, torque no (see dyno chart for peak torque rpm). Torque is what motivates your car, not hp. Horsepower is simply a measure of torque x rpm. Torque is the force, Hp is a calculation that serves a purpose
     
  13. Schwerin

    Schwerin Well-Known Member

    Vehicle(s):
    2019 Mustang BULLITT
    Joined:
    Jan 31, 2018
    Location:
    Philly
    Posts:
    2,365
    Likes Received:
    1,097
    0   0   0
    I'm still confused how if he's describing just normal TQ drop off how he's NEVER noticed it on ANY car before to the point that he thinks there may be a problem with the car.
     
  14. Burkey

    Burkey Well-Known Member

    Vehicle(s):
    2016 Mustang GT
    Joined:
    Feb 9, 2016
    Location:
    Australia
    Posts:
    3,493
    Likes Received:
    1,853
    Garage Profiles:
    1
    0   0   0
    It’s probably got a lot to do with the ultra tall gearing of the 18+ cars. I imagine that last 1000 odd rpm would feel like an eternity.
     
  15. Elp_jc

    Elp_jc Well-Known Member

    First Name:
    JC
    Vehicle(s):
    2019 Bullitt K7979, MR, Nav, B&O, Cover
    Joined:
    May 2, 2020
    Location:
    El Paso, TX
    Posts:
    1,585
    Likes Received:
    268
    0   0   0
    To begin with, the dyno chart on post #11 is not of a Bullitt, since there weren't any in 2018. And it wouldn't cut off at 6,800 rpm with the 3.73 Torsen, and increased top speed (163 vs 155). At any rate, according to the factory, peak HP is at 7,000 rpm, and peak TQ at 4,600, but haven't seen any dyno reflecting that yet. Maybe because I haven't seen any stock Bullitt dyno (alone) yet.

    Finally, the OP needs to remember as speed climbs, the more aerodynamic drag the car will have, slowing it down, so it's normal to feel less acceleration as rpm climb, and speeds exceed 60 mph or so. Also remember this car hits its top speed in 4th gear :).
     
Loading...

Share This Page