1/8 mile to 1/4 Mile Conversion

[turbonatr]

I see from time to time guys asking what their cars run in the 1/4 based on their 1/8 mile e.t. I am a bracket racer who relies on his timeslip to tune the car on a round by round basis. There is a wealth of info in your timeslip. More info than most people think. We use what is called a "run complete" to base a projected 1/4 mile e.t. based off of our 1/8 mile times. It's really a simple formula. Just take your 1/8 mile e.t. and multiply it by 1.57. This should put you very close to an estimated 1/4 mile e.t. Keep in mind the 1.57 constant is used for cars that hook pretty well. Cars that don't hook as well (such as front wheel drive rides) may see closer results by using a 1.53 constant. For the most part, with our cars using sticky tires, 1.57 works very well.

For example, the 1/8 mile e.t. that my GN ran in my sig. line was 6.87. Multiply 6.87 by 1.57 and you get 10.78. Pretty darn close to the 10.79 the car ran.

Hope this helps some guys out.

 

[azgn]

I went back over my timeslips and that formula is just about dead on.......within a few hundreths most of the time

I would be willing to bet that it won't work for cars that run (and tune) only the 1/8 mile....I know if I was running an 1/8, I'd crank the boost because the car would never be under a huge load......I couldn't sustain that power level thru the 1/4 tho without something going pop......

 

[turbonatr]

Yup, so long as your car hooks some what decently, the formula should be very close. Bracket racers use the formula in the event they lifted before the finish in an effort not to "break out". In this case, they would take their 1/8 mile time from that pass and do a run complete to make sure their dial-in time didn't need to be changed before the next round of eliminations.

Just a thought, would it hurt to make this thread a Sticky in this forum? May save someone some time (and bandwith) versus starting a new thread asking what their 1/8 mile e.t. equates to in the 1/4.