Just Commodores Forum Community

It takes just a moment to join our fantastic community

Register

Interpreting Dyno results: RWNM, motive force etc.

Discussion in 'General Discussion' started by VSCristian, Feb 22, 2016.

  1. VSCristian

    VSCristian New Member

    Messages:
    196
    Likes Received:
    1
    Trophy Points:
    0
    Joined:
    Jul 31, 2009
    Location:
    sydney
    Members Ride:
    1991 VP Commodore Executive V8 A4
    G'day Gents,

    I had a disappointing dyno run today, or so I think: my 5L only pulled 122.8rwkw.

    I think there's more to it than that: They did the run in second gear, and rw torque was 567Nm.

    Why would they do the run in second? and would the reading be affected? I was of the opinion that runs were done in third on autos.

    Dyno Time.jpg Dyno Chart.jpg
     
  2. immortality

    immortality Home of the smoky breakfast Bacon! Staff Member

    Messages:
    14,822
    Likes Received:
    2,865
    Trophy Points:
    113
    Joined:
    Apr 15, 2006
    Location:
    Sth Auck, NZ
    Members Ride:
    HSV VS Senator, VX s2 Calais S/C
    Power run should be done in 3rd gear been 1:1 in a 4l60 box. Doing a power run in a lower gear means you get torque multiplication through the transmission.

    Power wise, depending on condition and mods it's not totally bad. Stock VP put out a stout 160kw, allowing for drivetrain losses (I use .7457 just because..... and yes it's only a rough guide!) so that would suggest 119kw give or take.

    There is a big thread about this somewhere with more detailed explanations.
     
  3. VSCristian

    VSCristian New Member

    Messages:
    196
    Likes Received:
    1
    Trophy Points:
    0
    Joined:
    Jul 31, 2009
    Location:
    sydney
    Members Ride:
    1991 VP Commodore Executive V8 A4
    She has a HSV CAI and K&N Filter, and headers, high-flow kitty, and single 2.5" exhaust.

    If she got 567nm in second, which is 1.625:1 that would mean 354nm in third which is 1:1

    I don't know why they did it in second.

    Am quite disappointed to be honest. I thought she'd be in the 130s
     
  4. Brisbarnz

    Brisbarnz Active Member

    Messages:
    520
    Likes Received:
    36
    Trophy Points:
    28
    Joined:
    Feb 3, 2014
    Location:
    Brisbane
    Members Ride:
    Vh sle
    Run the 1/4 then do the math with car weight to get rwhp/kW
     
  5. Joeseb87

    Joeseb87 New Member

    Messages:
    7
    Likes Received:
    0
    Trophy Points:
    0
    Joined:
    Aug 26, 2016
    Location:
    Townsville
    Members Ride:
    Vk
    Some time ago I had a 308 that was rebuilt pretty stock slight cam increase and it made 118 RWKW
     
  6. lowandslow

    lowandslow Well-Known Member

    Messages:
    1,515
    Likes Received:
    227
    Trophy Points:
    63
    Joined:
    Dec 11, 2013
    Location:
    NSW
    Members Ride:
    V2 III Monaro
    Take it to the track and find out from your timeslip.
     
  7. delcowizzid

    delcowizzid on holiday

    Messages:
    6,893
    Likes Received:
    367
    Trophy Points:
    83
    Joined:
    Jul 8, 2008
    Location:
    NZ
    Members Ride:
    в∞ѕтεכ √&
    they are easier to run in 2nd or they allways kick back to 2nd as you start a run but if its programmed in the dyno what gear ratio its in the figures will still be valid
     
  8. chargedvx6

    chargedvx6 Active Member

    Messages:
    1,866
    Likes Received:
    13
    Trophy Points:
    38
    Joined:
    Dec 9, 2006
    Members Ride:
    VY SII HBD Calais L67
    The power is about right for the mods. Should definitely be run in 3rd gear to give a true torque reading.

    You could get between 110-140rwkw depending which type of dyno you go on and how it's set up so like the other bloke said, hit the 1/4 mile and punch in your full track mph and car weight into Moroso hp calulator and you will knwo the power of the car. Some will even calculate the peak torque but that's a bit inconclusive.

    Dyno is a tuning tool only
     

Share This Page