Weight vs ET

Wt. vs. ET Formula

It takes about 110 hp to equal .10 second E.T. or about 120 lbs. to equal .10 second ET on an alcohol FC.
A good approximation is to use the formula:
ET^3= ( 175 x wt ) / (HP)
^3 means that you cube the number
^.333 means that you take the cube root of the number
Here's an example:
ET^3 = (175 x 2310) / (2175)
ET = ( (404250) / (2175)) ^.333 = 5.71
Also, a good approximation of MPH is:
MPH = 1440 x ET
MPH = 1440 x 5.71 = 252.4
Here's an example of what you can do with an Excel spreadsheet using this formula:
--wt-- hp-- et-- MPH
2100 2175 5.53 260.5
2110 2175 5.54 260.1
2120 2175 5.54 259.7
2130 2175 5.55 259.3
2140 2175 5.56 258.9
2150 2175 5.57 258.5
2160 2175 5.58 258.1
2170 2175 5.59 257.7
2180 2175 5.60 257.3
2190 2175 5.61 256.9
2200 2175 5.61 256.5
2210 2175 5.62 256.1
2220 2175 5.63 255.7
2230 2175 5.64 255.4
2240 2175 5.65 255.0
2250 2175 5.66 254.6
2260 2175 5.66 254.2
2270 2175 5.67 253.8
2280 2175 5.68 253.5
2290 2175 5.69 253.1
2300 2175 5.70 252.7
2310 2175 5.71 252.4
2320 2175 5.71 252.0
2330 2175 5.72 251.6
2340 2175 5.73 251.3
2350 2175 5.74 250.9
2360 2175 5.75 250.6
2370 2175 5.75 250.2
2380 2175 5.76 249.9
-----------------------------------
----------------------------------
--wt-- hp-- et-- MPH
2300 2100 5.76 249.8
2300 2110 5.76 250.2
2300 2120 5.75 250.6
2300 2130 5.74 251.0
2300 2140 5.73 251.4
2300 2150 5.72 251.8
2300 2160 5.71 252.2
2300 2170 5.70 252.5
2300 2180 5.69 252.9
2300 2190 5.68 253.3
2300 2200 5.68 253.7
2300 2210 5.67 254.1
2300 2220 5.66 254.5
2300 2230 5.65 254.8
2300 2240 5.64 255.2
2300 2250 5.63 255.6
2300 2260 5.63 256.0
2300 2270 5.62 256.4
2300 2280 5.61 256.7
2300 2290 5.60 257.1
2300 2300 5.59 257.5
2300 2310 5.58 257.9
2300 2320 5.58 258.2
2300 2330 5.57 258.6
2300 2340 5.56 259.0
2300 2350 5.55 259.3
2300 2360 5.54 259.7
2300 2370 5.54 260.1
2300 2380 5.53 260.4
I hope this helps,
Greenlight

 

Interesting thread, try these age old physics formulae with adding and removing 100lbs...
(cube root (weight/Hp))*5.825

ie.. a 2000lb car with 2000hp will run a 5.825et now try it with 2100 and still 2000hp the car now runs a 5.920et. thats 0.0955 slower.

For mph...
(cube root(Hp/Weight))*234

The 2000lb car shows a 234mph and the 2100lb car shows 230mph.