Anybody else spreadsheet their runs?

TRUUBLE · Dec 2, 2007

I just spreadsheeted back to back runs and the numbers were really interesting. The only difference between the runs was the shift point was 300rpm higher on the faster run (9.81) and the burnout was longer on the slower run (9.95).

What I found was an almost completely linear imporvement at each clock. Here's what I mean:

60 Foot went from 1.378 to 1.345 . . a difference of .033 inc = .033
330 Foot went from 4.038 to 3.98 . . a difference of .058 inc = .025
1/8 Mile went from 6.311 to 6.224 . . a difference of .087 inc = .029
1K Foot went from 8.227 to 8.108 . . a difference of .119 inc = .032
1/4 Mile went from 9.959 to 9.810 . . a difference of .149 inc = .030 avg 29.8

Here's where it gets linear . . in the incrementals . . the car picked up almost exactly .030 plus the previous gain at every clock.

Interesting.

justinschmidt1 · Dec 2, 2007

so .033 of your 60 foot =
.15 off the 1/4 ..

haha interesting Ive always heard .1 off 60 is .2 tenths at the line..maybe it makes more off a differance with a faster car

TRUUBLE · Dec 2, 2007

justinschmidt1 said:
so .033 of your 60 foot =
.15 off the 1/4 ..

haha interesting Ive always heard .1 off 60 is .2 tenths at the line..maybe it makes more off a differance with a faster car

Right. But I think the change was due more to the change in shift RPM. In other words, I should have only picked up .066 going by the old rule of thumb. But, I had picked up .058 by the 330.

Obviously, the car hooked better with the shorter burnout, which explains the 60. But, there is an additional linear gain that I think had to do with the shift points.

I think continuing to spreadsheet this stuff is going to help me really dial things in. The other variables in my spreadsheet are timing, fuel trim, launch rpm (on the 2-step), tire pressure, and EGT readings.

98SILVERSTANG · Dec 3, 2007

I want to start doing this as well but to keep things like shock & strut settings, timing, rpm launch etc so I can have an idea what works at what tracks given certain conditions. Should make it easier.

Alain

TRUUBLE · Dec 3, 2007

98SILVERSTANG said:
I want to start doing this as well but to keep things like shock & strut settings, timing, rpm launch etc so I can have an idea what works at what tracks given certain conditions. Should make it easier.

Alain

Yep. That's why I have started doing it. Shock and strut settings are a good idea, I might have to add that in to mine. My car is 60 footing 1.34 and only MPHing 136 for a 9.81 ET, so I think my chassis is working pretty efficiently, but there is always room for improvement.