1 tenth in 60 foot = 2 tenths in 1/4 mile ET - myth?

Audi 1/4 mile, List & discussion forum
#8

I’ll take a nerdy approach at it…

Sounds like a marginal amount of tire slip at launch creates potential energy. When the tires finally grab hard they convert all the car’s stored potential energy into kinetic energy and the car shoots ahead and posts a higher MPH. The cost of the higher MPH is the millisecond or so during the first 60’ it takes to develop all that potential energy. Sort of like a slingshot - if you put it back just a little more it takes you an extra second to do so but the rock flies further and faster.

Conversely, if the tires grab before the cars generates enough potential energy it gets out of the blocks sooner (lower 60’ split) but peaks sooner down the track and doesn’t reach the max MPH at 1/4 mile.

#9

I like the nerdly explanation

#10

I think it would be interesting to plot out velocity and acceleration with a very sensitive/high polling gps. Overlay a quick 60 and slow 60 and see how they compare.

Does a pbox give you individual points when you pull the data? Phones and navi gps’s don’t have that high of a polling rate.

#11

Yes it gives you a crazy amount of data

#12

a 3 axis accelerometer logger could work well to get that data. I use an Onset UA-004-64 G HOBO Pendant Data Logger at work and you can get some very precise measurement. The full kit is $145. You can log at a maximum rate of 100 Hz.

#13

This is almost word for word what I said…its just more coherent. Also a lot is dependent on if your spinning or the car just making no power in that part of the power band…something like a turbo car with too big of a turbo for that range

#14

When I was at the track last week my fastest times were in the left lane that for some reason I got wheel spin on. I was looking at my slips scratching my head wondering Wtf. Your explanation seems to be a good one.

#15

What rpm did you launch at? Or did you use launch adjust the whole time?

#16

check these 2 passes out , same mph same 60 ft and 3 tenths difference.

http://i1270.photobucket.com/albums/jj615/Garrett_Hargreaves/Mobile%20Uploads/IMG_20140807_001140_zps730e1ff0.jpg

#17

Weird. Did you botch the 3-4?

The pass on the right, based on the 1/8 time /mph was on pace for 12.6@110

If you botch your third - fourth shift it will cost you mph but won’t cost you much et

Also note that the pass on the left is pretty much bang on what the car should have done the whole way down the track so I imagine this was I’ve of the hot passes

#18

When I was at the track last week my fastest times were in the left lane that for some reason I got wheel spin on. I was looking at my slips scratching my head wondering Wtf. Your explanation seems to be a good one.

#19

What rpm did you launch at? Or did you use launch adjust the whole time?

#20

check these 2 passes out , same mph same 60 ft and 3 tenths difference.

http://i1270.photobucket.com/albums/jj615/Garrett_Hargreaves/Mobile%20Uploads/IMG_20140807_001140_zps730e1ff0.jpg

#21

Weird. Did you botch the 3-4?

The pass on the right, based on the 1/8 time /mph was on pace for 12.6@110

If you botch your third - fourth shift it will cost you mph but won’t cost you much et

Also note that the pass on the left is pretty much bang on what the car should have done the whole way down the track so I imagine this was I’ve of the hot passes

#22

Ya I was hot lapping once it got cool. I didn’t miss the 3 4 and I was really scratching my head after that one. The passes where I missed a shift I just coasted to the end. Gave up.

#23

Ya I was hot lapping once it got cool. I didn’t miss the 3 4 and I was really scratching my head after that one. The passes where I missed a shift I just coasted to the end. Gave up.

#24

Makes sense (coasting) . No point wasting effort. Unless you’re chasing someone.

#25

Good advice. mainly because it avoids the slim possibility of a money shift.

#26

Makes sense (coasting) . No point wasting effort. Unless you’re chasing someone.

#27

Good advice. mainly because it avoids the slim possibility of a money shift.