1/8th to 1/4 mile conversion

A buddy of mine ran a 7.9 in the 1/8th mile in a Mustang. I am not sure of his MPH tho :( What could you expect the full 1/4 mile time to be? Where could I find the converison chart?

don't know where a chart is but i would guess about 14 secs. still a fast car. but what do i know???

That is a lot closer to 12's than a 14 sec time.:fact

Originally posted by dj1298 A buddy of mine ran a 7.9 in the 1/8th mile in a Mustang. I am not sure of his MPH tho :( What could you expect the full 1/4 mile time to be? Where could I find the converison chart? are you sure that's right? 1/8th mile in 7.9sec? 1/4 mile is 1320 ft., 1/8 mile is therefore 660 ft. (1/8th is half of 1/4).. so if his Mustang can do 7.9sec per 1/8th mile, then mathematically his 1/4 mile time is 15.8 sec (7.9 sec x 2).. EDIT: ok I totally ignored the fact that in the second half of a quarter mile run his engine would be climbing higher into the RPM range, thus giving him more power & torque, thus the second 1/8th time may be quicker.. so actually he may be closer to 14's... in that case, that is a pretty quick car... :yesnod

If the mustang ran a 7.9 in the 1/8th, his trap speed should have been around 90mph. At 90 MPH, an eighth of a mile takes about 5 secs. If you add 7.9 and 5 you get 12.9's. That is if his speed doesn't increase. So there is no doubt that that mustang is a 12 second car. There are so many variables when figuring a track times.

To get his average speed you can simply take the distance and divide by the time.....so 660'/7.9secs and convert to miles per hour...... 660ft 83.54ft 60sec 60min 1 mile -------- = ----------* --------- * ---------* ----------- = 56.95 mph 7.9secs sec 1 min 1 hr 5280ft this of course would be an average velocity and not the speed he was going when he crossed the 1/8th mile barrier since he started from rest. It has been about three years since I had dynamics in college but you could easily use equations to figure out his accel and the time it would take him to get to the 1/4 mile barrier. Plus im at work and dont have my books so I will let someone else figure it out. I would guess it would be in the 12 second time range as stated before

humm that didnt come out looking like I typed it but you can see what I did lol

Take whatever you run in the 1/8 multiply that times 1.55 and this will give you a a pretty acurate 1/4 mile time. Me for example: I run 6.50's in the 1/8 mile and 10.00's in the quarter. 6.50 X 1.55 = 10.07

I drag race my car all the time at Moroso and all of the 7.9 sec 1/8 mile traps I have end up running between 12.3-12.6 in the 1/4. Andreas Miko

Assuming that the acceleration is somewhat constant (no NOS or Turbo) then the correct formula for the 1/8th mile to 1/4 mile conversion is: 1/8th mile time x 1.5832 sec = 1/4 mile time I have a more accurate way of measuring, but I would need all of your times: 60', 330ft, 660ft, etc. (Rxn time notwithstanding). If you had all of the aforementioned measurements, it would be possible to calculate the most resonable acceleration via Kinetic Equations.

We go to a small local track. They only post trap times. I think it has to do with insurace reasons for not showinghte actual speed of the car. No other measuresments are given:( But the track is like $15 for all you can run till 12pm! Originally posted by dtd8671 Assuming that the acceleration is somewhat constant (no NOS or Turbo) then the correct formula for the 1/8th mile to 1/4 mile conversion is: 1/8th mile time x 1.5832 sec = 1/4 mile time I have a more accurate way of measuring, but I would need all of your times: 60', 330ft, 660ft, etc. (Rxn time notwithstanding). If you had all of the aforementioned measurements, it would be possible to calculate the most resonable acceleration via Kinetic Equations.