Accelerometer Data and shift points from track rental

[murphster]

Just like backpressure data I posted in another thread, I got a bunch of accelerometer data from a track rental last week from a bunch of runs. My goal was to try and see what my optimal shift points were. Luckily I got enough runs with different shift points so I can at least get an idea. The data looks clearer on the 1-2 shifts. The boost was raised for each successive run too and its interesting how you can see the couple point of the converter rise as power rises. As the power increased I also got later on the 1-2 shift even though I was trying to shift before 6000 rpm.

For each run I noted the max rpm recorded before each shift per XFI. For reference, the first run was at around 18 psi boost and 10.2@131mph and the last run was 27psi boost and 9.3@145mph....

RPM is in blue, acceleration is the greenish color.

Run 1. 5550 1-2 shift 5350 2-3 shift

Run 2. 5800 1-2 shift 5450 2-3 shift

Run 3. 5850 1-2 shift 5550 2-3 shift

Run 5. 5650 1-2 shift 5750 2-3 shift

Run 6. 6050 1-2 shift 5700 2-3 shift

Run 7. 6200 1-2 shift 5800 2-3 shift

Run 8. 6350 1-2 shift 6050 2-3 shift

 

[murphster]

From the data, it looks like my optimal shift point is around 5700-5800. The way I understand it you want the acceleration to be smooth before and after the shift with no increase or fall off. A late shift will show an increase in g and an early shift will show a drop off in g.

Run 1. 5550 1-2 shift 5350 2-3 shift
Early shift?

Run 3. 5850 1-2 shift 5550 2-3 shift
Looks like a pretty good shift ?

Run 8. 6350 1-2 shift 6050 2-3 shift
Late shift?

Thoughts?

 

[bison]

My thoughts are its time to turn it up!


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[turbobitt]

My thought is if the accelerometer picks up after a shift then you are probably shifting to late. I would agree on the assumption of keeping it smooth as possible to determine the best shift points. I can also see from your data that it appears you are ramping in the boost over the first 1-1.5 seconds. It would be nice to see what the wheel speed is doing and makes me wonder if you can hit the tires a little harder at the launch although it looks like there may be some slight spin. Looking at the data, It also looks like your not on any type of 2-step....interesting.

Data looks good and can be fun to analyze.