double06

As a general rule of thumb what are you guys seeing. All thinigs being equal but say a good launch verusus say a great launch. If a car did a 60 foot of say 1.60 and a 1/4 mile et of 10.7 then came back around did everything identical but hit a 1.40 60 foot what would his et be? I thought the ratio is like 1.5x to 1 so a .20 second improvment in 60 foot will translate to a .30 second et in 1/4 mile (.20 x 1.5). I have even heard as high as 2x.

dgdoc

On the C6Z, I've been using 1.5x to approximate the ET improvement from the difference in 60' times. Of course, this is just an estimate and there are *many* other factors that can come into play.

Ranger

In a quarter-mile pass, there are a lot of discrete driver actions that combine to yield ET and Trap speeds. The 60-foot time is important but only one of them.

It takes very consistent driving to isolate the impact of one sole factor, the 60-foot time. And as you might guess, I've been able to measure that with some precision.

On my stock car, on drag radials or stock tires, I see a 1.15x to 1.25x change in ET based on changes to the 60-foot number. That's apples-to-apples-to-apples. Same car; same driver; same track; same day; same conditions.

In my experience the rule-of-thumb of a 1.5x factor cloaks a lot of other variables that my approach eliminates.

Ranger

double06

This is helpful. Ranger with the number of passes and your consistency you have certainly a lot of knowledge on subject.