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working out the figures of a dyno run?

Discussion in 'Performance' started by swamper, Mar 8, 2012.

  1. swamper

    swamper Zorg Guru (V)
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    as it says.....how do you work out engine power from the readings at the wheels?
    how much is lost in the transmission?
    can you work out torque from this?
     
  2. r37

    r37 Dedicated Member

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    it depends on the dyno. Some will give you a WHP (wheel horse power) and some with give a BHP (brake horse power). WHP is pretty self explanatory, brake horse power is measured by letting the car run down by 1k revs or so and then measuring the mechanical drag (braking force) and using that value to work out the power needed to turn all the cogs and stuff which is then added to the WHP to give a BHP figure that is more equal to the engine power at the crank. All manufacturers quoted figures are taken at the crank because they test the engines on a testbed with nothing attatched. On average the loss in the drivetrain is between 15%-20% so if your car has a quoted 100hp it will likely put down 80-85 at the drive wheels. Over time components wear and the amount lost increases. If you have a car dyno'd you will get out a horsepower reading aswell as a torque reading. Torque and horsepower are allmost competely unrelated and there is no reliable way of working one value out form another.
     
  3. swamper

    swamper Zorg Guru (V)
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    cheers Dan.....so on the safe side you would add 20% WHP to get you engines BHP?
     
  4. r37

    r37 Dedicated Member

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    at a rough guess i'd say so.
     
  5. z3cade

    z3cade Zorg Guru (III)
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    You having yours dyno'd Swamper? :coolsteer)
     
  6. swamper

    swamper Zorg Guru (V)
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    its been done ;)
     
  7. billz

    billz Zorg Expert (I)
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    So what was the result then Wayne.
    bill
     
  8. badman gee

    badman gee Guest

    There was a thread on .net by spacemonkey i believe.

    Mark
     
  9. HornelZ3M

    HornelZ3M Zorg Addict
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    Come on then lets have it :coolsteer)
     
  10. z3cade

    z3cade Zorg Guru (III)
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    Yes what was it!?!?

    Is yours standard Wayne? If so anything around 305bhp is about the norm so Evolve say for an S50


    Mine before the cams were fitted was stage 2 tuned at Evolve,
    That's Simota, decat, super sprint exhaust and remap and achieved 320.5 bhp..
     
  11. swamper

    swamper Zorg Guru (V)
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    309 bhp...so not bad for and car of that age....it looses 1 bhp a year :))
    yep its standard Liam
    if i keep it for 100 years.... :-^
     
  12. z3cade

    z3cade Zorg Guru (III)
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    That's very good swamps ;) so whens it going in for the remap :D
     
  13. swamper

    swamper Zorg Guru (V)
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    not for a while mate...there's a few thing i want to do first (as we talked about ;) )
    im happy with what iv got...for the time being :))
    i think with this one i want to keep it standard as poss....maybe a little nice trick here and there ;)
     
  14. z3cade

    z3cade Zorg Guru (III)
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    Fair play matey.. If i had the choice i would keep it standard but as mine was already done i couldnt complain ;)

    Enjoy it wayne.. it looks a cracker your M
     
  15. swamper

    swamper Zorg Guru (V)
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    cheers matey....cant wait to have them all together at the Fest :ymhug:

    the thing is you cant complain........your car came done...that must have saved you a small fortune and a lot of messing....looks the part mate ;)
     
  16. z3cade

    z3cade Zorg Guru (III)
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    Thanks mate, yeah i couldnt have asked for a better example.. i feel very lucky indeed.
    Trouble is im always trying to find something to tinker with but there just isnt...! ;)

    I cant wait for Zfest too... its going to be a weekend to remember!! :ymhug:
     
  17. badman gee

    badman gee Guest

    you too having a kiss and cuddle ;)
     
  18. swamper

    swamper Zorg Guru (V)
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    bit of man luv going on Mark...you want in :ymblushing:

    just for you.. :ymdevil:

    [​IMG]
     
  19. z3cade

    z3cade Zorg Guru (III)
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    God... Don't tempt him Wayne... #-o

    I've heard story's of his :baa rustling days.. :-s
     
  20. badman gee

    badman gee Guest

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