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Author Topic: 135bhp at flywheel or wheels  (Read 2315 times)

Offline Jaybo Abarth

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135bhp at flywheel or wheels
« on: July 28, 2012, 08:58:25 pm »
Does anyone know if the 135bhp is at the wheels or the flywheel ?

Thanks jay

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    Offline Griffs998

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    Re: 135bhp at flywheel or wheels
    « Reply #1 on: July 28, 2012, 09:48:03 pm »
    flywheel (crank)

    Offline dan vbv

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    Re: 135bhp at flywheel or wheels
    « Reply #2 on: July 28, 2012, 11:00:36 pm »
    so how do most that go on a roling road make more than 135 at the wheels
    2002 ford ka rust edition

    2011 abarth 500 is now lightly modified

    1000hp single turbo supra 6speed manual   i want one

    Offline Griffs998

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    Re: 135bhp at flywheel or wheels
    « Reply #3 on: July 28, 2012, 11:26:11 pm »
    the answer to jaybo's question is that its a flywheel figure - manufacturer figures are notoriously low to stop them being sued if the customer after buying the vehicle on the stated figures finds out that they were inflated by the manufacturer in the hope of attracting a few more sales

    Dyno figures are largely arbitrary on their own - they're only good for establishing a baseline to then see how any mods have affected the car

    Offline GTMartin

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    Re: 135bhp at flywheel or wheels
    « Reply #4 on: July 29, 2012, 07:33:40 am »
    so how do most that go on a roling road make more than 135 at the wheels

    Figures quoted on a rolling road are corrected figures from the crankshaft.

    On a rolling road the power is measured through the wheels, then when it coasts down the rolling road calculates the losses through the drivetrain, to give an estimated power output at the crankshaft.


    Offline dan vbv

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    Re: 135bhp at flywheel or wheels
    « Reply #5 on: July 29, 2012, 11:23:52 am »
    when mine got done it was at the wheels (i asked)  :thumb:

    is thear a rough gide to how much diffrence thear is betwean the 2

     
    2002 ford ka rust edition

    2011 abarth 500 is now lightly modified

    1000hp single turbo supra 6speed manual   i want one

    Offline GTMartin

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    Re: 135bhp at flywheel or wheels
    « Reply #6 on: July 29, 2012, 01:02:20 pm »
    There is no rough guide as it depends in how 'loose' the drivetrain is. I think ours accounted for 20bhp. Only accurate way is to get the engine on an engine dyno, but there again you cannot replicate huge blasts of air like you get driving down a road.

    Offline Griffs998

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    Re: 135bhp at flywheel or wheels
    « Reply #7 on: July 29, 2012, 01:30:27 pm »
    10 - 20% is a rough estimate - with 4wd being higher still - as GTMartin says a dyno cant replicate the air flow and recreate the high pressure zones that driving on the road creates - also when the engine is coasting down to calculate crank HP the drivetrain components arnt meshed hard together as they would be under acceleration so even drive train loses can be only very vaguely guessed at with other variables like tyre pressures and operator efficiency and ultimate dyno quality al being significant variables also - they'll give a very ballpark figure but are much more useful for tuning comparisons

    Offline dan vbv

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    Re: 135bhp at flywheel or wheels
    « Reply #8 on: July 29, 2012, 01:50:30 pm »
    mint so 172 bhp on my car is alot more at the crank  :thumb:
    2002 ford ka rust edition

    2011 abarth 500 is now lightly modified

    1000hp single turbo supra 6speed manual   i want one

    Offline GTMartin

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    Re: 135bhp at flywheel or wheels
    « Reply #9 on: July 29, 2012, 01:53:19 pm »
    Are you sure the 172 was corrected at the crank because that is what they usually quote? The printout should confirm.

    I would take all figures with a pinch of salt as the dyno can be set to whatever figure you want it to read.

    Offline Griffs998

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    Re: 135bhp at flywheel or wheels
    « Reply #10 on: July 29, 2012, 01:53:50 pm »
    if you're on the standard turbo that figure will be at the crank or has been heavily manipulated

    Offline dan vbv

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    Re: 135bhp at flywheel or wheels
    « Reply #11 on: July 29, 2012, 02:08:01 pm »

    ok my bubble has been burst

    i think i got confused when my car was on the rolling road the graph was rit during the run and did not change during the coast down ::) o well we will see next week end when its at sedox again :thumb:

    i have had a idear the 135 that is quoted might be at the wheels and when poeple put thar cars on the rollers thay get around 150hp witch is ajusted by the dyno from what thay gat at the wheels

    so abarth might not have under recorded the power of the 500 :thumb:
    « Last Edit: July 29, 2012, 02:22:40 pm by dan vbv »
    2002 ford ka rust edition

    2011 abarth 500 is now lightly modified

    1000hp single turbo supra 6speed manual   i want one