[Diy_efi] BHP calculations

[Jörgen Karlsson]

Hi,

I am interested in a copy of the spreadsheet, I would like to compare it
with the one I am using.

Jörgen Karlsson
jorgen.m.karlsson at home.se

> -----Original Message-----
> From: diy_efi-admin at diy-efi.org [mailto:diy_efi-admin at diy-efi.org]On
> Behalf Of Hugh Keir
> Sent: Monday, July 29, 2002 11:49 PM
> To: diy_efi at diy-efi.org
> Subject: [Diy_efi] BHP calculations
>
>
> I am working on a spreadsheet to calculate BHP from datalogged
> information.
>
> The basic formula I am working to is:
>
> Engine BHP = acceleration BHP + wind drag BHP + transmission loss BHP.
>
> I need help with the formula to calculate acceleration BHP.
>
> I know the weight of the car and the change in engine RPM over time.
>
> I can therefore use F=ma  ( force = mass * acceleration ).
> Where I think F = lbs, mass = slugs ( 32.1 lbs each ) and acceleration =
> ft/second change in speed, to calculate the acceleration BHP
>
> Horsepower is 550ft lbs / second. I am not sure how you get BHP from F
> above, do I just divide by 550 to get BHP?
>
> I have used the wind drag calculations from
> http://members.home.net/rck/phor/06-Speed.html which seem OK and will be
> able to get some transmission loss figures from some rolling road runs.
>
> Your help will be greatly appreciated.
>
> I can copy the finished spreadsheet to anyone interested.
>
> I have used a variable air density input to the spredsheet and hope to add
> wind direction to normalise the readings.
>
> Thanks
>
> Hugh
>
>
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>
>



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