Formula for Horsepower calculating by MPH ran in 1/4 mile

Pure stock Busa with full tank of gas= 560 lbs. ( Digital scale, calibrated daily: .1 % tolerance )

[This message has been edited by c.dolan (edited 08 July 2000).]
 
Y'all mean pure stock w/ or w/o you on it?
Orig. # sounds right w/o rider I think...?

NO I mean what super said, around 475 or so.

[This message has been edited by 'lantabusa (edited 07 July 2000).]
 
Taking frontal area of Busa. 5.3ft^2 this formula will get you close...

((0.00436*MPH)^3)*(lbs)

Lbs is weight of bike with rider
 
I have been tabulating some information to derive at a formula to calculate the rear wheel horsepower of a motorcycle on a Dynojet Dynamometer based off of the MPH ran at a dragstrip. I know there are a ton of variables, but this is only a "rough guide".
The intent of this post is not to blow holes in this style of calculating, but more to find out if the numbers work for others. We could "finesse" these numbers with some good input from others who have known good runs on their bikes...see if it works for you and your replies would be grateful.
Formula: Top Speed divided by 230 = "Y".
Then Y X Y X Y X bike and rider weight = H.P.
Freddie
 
I preferably would like to figure it for rear whell, but I suppose it isn't too awfully important...we know what the power difference is from engine to rear wheel anyways. Thanks for the input up to now everyone.
 
HP=(MPH/234)cubed X Weight

For example lets say that our Busa ran 139 mph in the quarter. Here is what the equation would look like

HP=(139/234) cubed--you know to the 3rd power X the weight (725lbs.) 550 lbs. for the Bus + a 175lb rider.

.20960 X 725 = 151.96 HP

Its not perfect and assumes you have some ability at the strip. Trap speed shows HP.

Bob
 
Crissakes...getting weight is like all the horsepower numbers you hear! All over the place! We need some carved in stone numbers of bike and rider weights. July 15th...Lebanon Valley New York for the daytime... Summer bike and sled shootout then off to Englishtown New Jersey for Saturday night the 15th. Will get my riders on the scales at these tracks to know for certain what they weigh. Northeast guys...hope to see some of you at one of these tracks...gonna be fun. Freddie.
 
148.5 is what i ran tonight at d/w 42 and its a crappy track.hopin for 150 next week.not bad for a stock motor and no shifter and the balancer still in the motor.
 
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