Horsepower Run Curve from ET Analyst

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200cfm
Posts: 240
Joined: Wed Mar 03, 2010 10:52 am

Horsepower Run Curve from ET Analyst

Post by 200cfm »

Ok, here is the challenge. Larry's ET Analyst gives the printout of the run from launch to finish with distance every 10 feet, g forces, time lapse, mph and rpm value at each 10 ft. s. How do I calculate HP Run Curve for the run? What formula? (tom c)
200cfm
Posts: 240
Joined: Wed Mar 03, 2010 10:52 am

Re: Horsepower Run Curve from ET Analyst

Post by 200cfm »

Found these formulas and thought they would work but can't come up with a formula that uses the g forces from a run to equate to a force value. The article is a good read. I thought his formula of 1 hp = 375 ft-lbs X mph would work but ????

Newton says: force = mass X acceleration. What are the units in acceleration? Mass would be vehicle weight in lbs. I think.

http://craig.backfire.ca/pages/autos/horsepower
200cfm
Posts: 240
Joined: Wed Mar 03, 2010 10:52 am

Re: Horsepower Run Curve from ET Analyst

Post by 200cfm »

Came up with the following which calculate on my time slips from 0 movement to any position on the run distance.

Work = Force X Distance = Mass times Final Velocity squared divided by 2.

Once you get the work value in newton-meters you can convert to Power.

Power = Work divided by Time.

Once you get the Power in watts you can convert by 1 HP = 745.7 watts.

Above assumes no friction or aero drag, so strictly required force to move "X "mass from 0 to a Final Velocity. I quess it could be considered rear wheel hp or ???. (tom c)
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