TireSmoke.org

At the track last night, i got to play with my Dragy a little bit. Very cool little device.

How about 0-60 of 2.7 seconds??

That is surprisingly accurate. It seems like it is accounting for the roughly 2-foot rollout. I am quite surprised at how well that data correlates to the track position sensors. That is a really cool data set. Definitely a cool device to have.

2.7 seconds is almost exactly 1G for 0-60, depending on how the rollout is included. While tires are not purely friction in their contact with the track, friction theoretically limits us to 1G of acceleration (positive or negative) as a maximum. We get around that limit by lifting the car (4 link or ladder bar drives the tires hard into the ground while raising the car's center of gravity), which allows us to briefly exceed 1G of acceleration. We also can eventually get around that by creating downforce aerodynamically, but that can only happen once we have some air speed. That is a really good mark, though. It suggests that you have figured out how to manage the throttle on the launch to maximize the limited traction. There was little doubt that from 0 to 60 you are traction limited rather than horsepower limited, but the numbers confirm that.

one drawback on the dirt drags is getting the timeslips. they don't put your car # on them so unless someone is there to pick them up they got lost. Dragy would help with that so I might be getting one soon.

Does your Dragy allow you to set specific distances to get your times at, or are they present? Could you theoretically set it for 200' and know your time at that distance?

-BP

Yes, I think you can set up custom distances like that.