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Mph to time calc9/20/2023 ![]() ![]() engine power, and the details of the torque or horsepower curve.In his journal article, Professor Fox lists the following key variables that affect ET and MPH. McCaul that made me aware of the work of himself, Fox, Huntington, and others in the 1950s, 1960s, and 1970s, and of Fox's most recent (2001) empirical formulas, which are In fact, it was a recent personal communication from Mr. Also in 1973, Earles McCaul published an article in the November issue of Hot Rod magazine titled Drag Strip Dyno. Fox described this basis in 1973 in an article in The American Journal of Physics (see the References section at the end of this web page). Fox, who has been the president and CEO of Fox Racing USA in Morgan Hill, CA (maker of motorcross, BMX, and mountain bike apparel), determined the theoretical basis for Huntington's formula. In 1964, University of Santa Clara, California Physics Professor Geoffrey T. It represented many hours of work and tedious slide rule calculations over a period of 10 years." "Anyway, I know I was the first to derive ths type of equation, based on true net HP. However, there was more scatter in the plotted points here, due to wider variations in traction between cars. That one is a constant of 6.29 times the cube root of the lbs.-per-HP ratio. "Incidentally, I did the same thing with a formula for quarter-mile e.t. "Note that I only tested cars with trap speeds between 70 and 115 mph. And actually there was amazing correlation. The above formula is the average line through the plotted points. Using the gross weight of the car and the tested true clutch HP, the lbs-per-HP ratio was derived. (The gear effect was compensated by using a factor to allow for engine and drive line rotating inertia.) Anyway, the car was tested on a quarter-mile to accurately determine the terminal speed at the end of the quarter. What I would do is test the car with an accelerometer - and several complex equations - to determine the true peak HP delivered at the clutch under accelerating conditions, usually in a gear giving the HP peak between 60 and 90 mph, to make it easier to get consistent accelerometer readings. It was the result of 40 or 50 road and strip tests of many different cars. The constant is 224 not 225, and MPH is calculated by dividing 224 by the cube root of the lbs.-per-HP ratio. That explanation is reproduced below with some minor editing. ![]() "weight" is the the total weight of the vehicle (with driver) in pounds.Įarles McCaul fowarded to me a letter sent to him from Roger Huntington (August 1976), in which Huntington explains how he derived his empirical formula."hp" is the peak engine horsepower output at the clutch (net power), and."224" is the empirically determined coefficient that includes the necessary unit conversion factors,."MPH" is the terminal speed (trap speed),.Huntington also determined a formula for 1/4-mile elapsed time. Huntington presented his graph for predicting 1/4-mile terminal speed in an article titled Horsepower at the Drag Strip, pages 50-53 in the December 1958 issue of Rod & Custom magazine (thanks go to Earles McCaul for this information). In the 1950s, the late Roger Huntington (please see ), author of numerous books and magazine articles, was perhaps the first engineer and automotive enthusiast to empirically determine mathematical relationships between a vehicle's performance in a 1/4-mile drag race and a vehicle's power and weight. hp & wgt Calculators for 1/4-Mile ET & MPH vs. ![]() Pace is often expressed as ‘# minute mile’ or ‘# minute kilometer’.Stealth 316 - Formulas for 1/4 mile ET & mph vs. Pace is the number of minutes and/or seconds is takes to walk, run, etc. Pace: Your pace in minutes and seconds (or just minutes accurate to 2 decimal places). And ‘Yards per Second’ and ‘Meters per Second’ are most useful for shorter distances. ‘Yards per Minute’ and ‘Meters per Minute’ are the most useful units for intermediate distances. ‘Miles per Hour’ and ‘Kilometers per Hour’ are more useful units for longer distances. Speed: Your speed, accurate to 2 decimal places. Title: A title for these calculator results that will help you identify it if you have printed out several versions of the calculator.ĭistance: Your distance, accurate to 2 decimal places, and its unit (miles, yards, kilometers, meters).ĭuration: The duration or time, expressed in hours, minutes and seconds. How fast was I going to cover the given distance in the given amount of time?įind the speed and pace you walk, run, bike, skate, or row when you know the distance and duration. ![]()
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