horse power/acceleration

[Tom Sharpe]

Good stuff, I just wanted a relative number - crankshaft acceleration at x rpm,
y load for comparison/tuning. If we change the mixture at point x-y what does
the crank acceleration (power?) do??????  just more food for thought...  TomS

Ord Millar wrote:

> Take the acceleration at some point in your curve, call it A, and multiply
> by vehicle mass.  This gives the linear force exerted by the rear wheels.
> (front wheels?).  F=MA  (it is convinient to measure acceleration here in G,
> and mass in lbs).
>
> Torque at the rear wheel is F / (D*2*PI), where D is wheel diameter.  Engine
> torque is rear torque / axle ration / transmission ratio + driveline loss.
> (keep D in ft for simplicity, loss in ft-lbs)
>
> Engine HP is engine TQ * engine RPM / 5251.  (when TQ is in lbs-ft)
>
> So:  HP = (MA/(D*2*PI)/ratio+loss) * RPM / 5251.
>
> Add in air & rolling resistance, and you're almost there!
> -----Original Message-----
> From: Jeff W <sierraj at home.com>
> To: diy_efi at efi332.eng.ohio-state.edu <diy_efi at efi332.eng.ohio-state.edu>
> Date: Thursday, May 13, 1999 7:35 PM
> Subject: horse power/acceleration
>
> >dear sir
> >I am writing to you because I am looking for the correct
> calculation/formula
> >for finding the approximate horse power conversion from vehicle weight and
> >acceleration curve.
> >    I am presently in Vancouver community college, in Vancouver B.C and my
> >instructor (Dave William's) gave me your e-mail address feeling that you
> may
> >be of some help to me.
> >
> >vehicle weight + acceleration curve + some other things I don't know=
> >approximate HP at RPM.
> >thank you!
> >Jeff Weinberger
> >sierraj at home.com
> >
> >
> >