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Two idle rpm's

Discussion in 'Racer Physics and Technical' started by drholmes1003, Feb 15, 2014.

  1. Hi all,

    Need a bit of help here. In my Formula SAE model for Racer I have defined idle revs to be at 3000rpm and it does indeed hold the idles at 3000rpm on neutral but only until I throttle it past 4000rpm, when it suddenly starts increasing the revs until 7482rpm. When I look at Ctrl+4 controls it says that my throttle is at 38.62% and never falls below, disregarding the fact that I use analog controls for model development on my laptop.

    Also, maybe this will help:

    engine
    {
    x=0
    y=0
    z=0
    size=0
    mass=0
    enable_stall=0
    start_stalled=0
    stall_rpm=0
    starter=0
    starter_torque=0
    start_rpm=2500
    idle_rpm=3000
    max_rpm=10000
    rev_limiter_time=10
    min_warn_rpm=5000
    max_warn_rpm=10100
    curve_torque=torque_delft.crv
    max_torque=1
    braking_coeff=0.2
    braking_offset=0
    autoclutch=0
    autoclutch_rpm=3000
    ;launch_control=
    inertia
    {
    engine=0.02
    }
    shifting
    {
    automatic=0
    cut_throttle=1
    shift_up_rpm=9500
    time_to_declutch=1
    time_to_clutch=1
    time_in_neutral=30
    shift_down_rpm=5000
    time_to_declutch_down=1
    time_to_clutch_down=10
    time_in_neutral_down=8
    blip_throttle=0.25
    fast=1
    }
    }

    Please let me know if you suspect you might know the solution to the problem or need more information about it.

    Many thanks,
    Anton
     
  2. I would check your controller, as your engine stuff looks good and a quick port into Racer, and I had no such issues with it. (at idle it was at about 1.6% throttle).
     
  3. Check out http://www.racer.nl/tutorial/engine.htm#enginerpm for an explanation of engine.idle_method, a parameter the code snippet in your post appears to be missing. Other than that, it sounds like the combination of the particular engine torque curve file characteristics around the idle rpm range and perhaps the engine inertia setting as well could be behind the unwanted increase in engine speed. The effect actually occurs sometimes when we're playing with fairly peaky torque curves, like on highly turbocharged engines, where there is relatively little torque available at low engine speeds.