[tech] Why is the 60' ET so important?
 

by Mark Towslee

If you've done any drag racing, you've probably noticed that racers seem obsessed with 60' ET's. There's a good reason for this. The first 60' of the track set the stage for the rest of the run and has a huge effect on the ability to "run the number" when bracket racing. Many beginning racers seem more concerned with top end mph thinking that if the car goes faster at the end of the track they'll pick up ET. However, top end speed isn't really as important as it first appears.

Here's why - Think about the percentage of time that you spend traveling the first 60' compared to the last 60' and you'll see that you spend a relatively large amount of *time* in the first 60' of the track. Now lets take that out to 330' and the compare it to the last 330 feet of the track ...

I went through some timeslips and found a car that ran 10.21 in the 1/4 mile. Now lets do some analysis:

60' = 1.470 or a total of 14% of the total ET
330' = 4.167 or a total of 41% of the total ET

So, you travel 25% of the total distance and you've spent 40% of your total ET to travel that first 25% of the track.

Now lets look at the 1000' to 1320' time compared to the 330' ET:

To get from the 1000' timer to the 1320' timer it took 1.73 seconds (10.213 1320' ET - 8.48 1000' ET) for a total of 17% of the total time. You've only spent 17% of your total ET to travel the last 25% of the distance.

So, as you can see, it takes almost as much *time* to travel the last 320' as it does the first 60' of the track and it takes 2.4 times longer to travel the first 330 feet as it does to travel the last 330' feet - actually 320' feet but its close enough for this comparison.

This is why you gain ET by concentrating on the first few feet of the track. You spend a proportionately greater deal of *time* in the first few feet and since ET is *time* it's easier to gain ET by concentrating on the launch.

From my own personal experience: My car picked up almost .3 in the 60' and about .4 overall when I switched from a 2500 converter to a 3500, MPH actually stayed about the same. It would have taken an awful lot of MPH at the top end to pick up that much ET.