PerformanceBox vs AP-22 results

Recently I began testing with the RaceLogic Performancebox gps data logger.  Previously I had been testing with the Race Technology AP-22 accelerometer-based performance meter.  This test is intended as a side-by-side comparison of the two meters on simultaneous runs.  I ran both meters at the same time, on the same runs, then have attempted below to put like-results side by side for comparison.

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The Performancebox is a gps based data logger.  It takes 10 position readings a second and calculates performance data based on GPS satellites.  The AP-22 uses accelerometers and ‘dead reckons’ the position of the vehicle based on acceleration and time.  Both are valid approaches.  The results one might expect to be somewhat different because the meters begin the run based on different rules, and measure the result in different ways.  However, my test results below seem fairly consistent between the two meters.

Summary Results:

PB AP-22
0-60 6.60 6.63
0-60 6.88 6.62
0-60 6.42 6.12
0-60 6.10 6.03
0-60 7.07 6.72

Detailed Results:

PerformanceBox Test Data AP-22 Test Data
MPH Time(s) Dist(f) mph s g ft hp
10 0.90 6.56 10 0.9 0.5 6 55
20 1.85 27.49 20 1.83 0.48 26 107
30 2.73 59.43 30 2.68 0.59 57 198
40 3.78 113.93 40 3.76 0.35 113 160
50 5.12 202.33 50 5.08 0.32 201 189
60 6.60 322.09 60 6.63 0.26 326 193
Pk Pwr: 58.5mph 6.37s 304ft 209hp
Peak G: 30.3mph 2.70s 58ft 0.60g
PerformanceBox Test Data AP-22 Test Data
MPH Time(s) Dist(f) mph s g ft hp
10 1.09 6.97 10 0.92 0.53 6 57
20 1.95 25.87 20 1.76 0.55 24 122
30 2.89 60.62 30 2.69 0.46 59 156
40 3.95 115.38 40 3.74 0.40 113 180
50 5.30 204.91 50 5.08 0.32 202 185
60 6.88 332.43 60 6.62 0.27 326 195
70 8.76 512.24 70 8.49 0.22 505 194
Pk Pwr: 66.2mph 7.71s 427ft 209hp
Peak G: 20.2mph 1.77s 25ft 0.56g
PerformanceBox Test Data AP-22 Test Data
MPH Time(s) Dist(f) mph s g ft hp
10 0.91 5.56 10 0.74 0.62 5 67
20 1.67 22.23 20 1.48 0.56 21 124
30 2.61 56.86 30 2.41 0.47 55 158
40 3.65 110.42 40 3.42 0.42 108 189
50 4.95 196.19 50 4.70 0.32 192 189
60 6.42 315.16 60 6.12 0.30 307 215
Pk Pwr: 64.7mph 6.86s 375ft 228hp
Peak G: 16.3mph 1.19s 13ft 0.66g
PerformanceBox Test Data AP-22 Test Data
MPH Time(s) Dist(f) mph s g ft hp
10 0.65 5.54 10 0.75 0.58 5 64
20 1.42 22.38 20 1.49 0.61 21 134
30 2.36 56.86 30 2.41 0.5 55 166
40 3.37 109.27 40 3.41 0.44 107 198
50 4.64 193.37 50 4.64 0.35 189 201
60 6.10 311.02 60 6.03 0.3 301 215
70 7.77 471.17 70 7.67 0.24 458 211
Pk Pwr: 65.8mph 6.93s 384ft 233hp
Peak G: 19.4mph 1.44s 20ft 0.62g
PerformanceBox Test Data AP-22 Test Data
MPH Time(s) Dist(f) mph s g ft hp
10 1.19 7.48 10 0.93 0.49 6 54
20 2.09 27 20 1.79 0.54 25 120
30 2.99 60.43 30 2.68 0.46 58 155
40 4.07 116.39 40 3.76 0.39 114 177
50 5.44 206.73 50 5.14 0.3 205 178
60 7.07 338.1 60 6.72 0.27 333 195
70 9.04 527.18 70 8.70 0.19 523 171
Pk Pwr: 64.4mph 7.51s 405ft 203hp
Peak G: 25.1mph 14.01s 970ft 0.65g

Conclusion:

The meters tend to read similarly.  The AP-22 results on average for the runs shown were 0.19sec lower at 60 mph.

The AP-22 results appear to be similar to the PB results if rollout is considered.

Testing the test gear

I have been testing for the last few years with the Race Technology AP-22, which is a nice accelerometer based performance meter.  Recently I have acquired a Race Logic PerformanceBox, which is a gps-based performance meter.  The PerformanceBox is targeted as a consumer version of the Vbox unit that some car magazines use for acceleration testing.

The first tests I ran with the AP-22 back when I acquired it were to test it side by side with my previous test unit, a Tesla G/Tech Pro.   The AP-22 has the advantage of providing more detail about the test run, in that it provides 0-10, 10-20, 20-30 mph acceleration etc up to the max velocity set for the test.  The earlier G/tech Pro only gave 0-60mph or 60 ft, 330 ft as part of a quartermile run.  Having the greater detail of the intermediate results makes it much easier to determine exactly how a modification to the Cadillac has effected performance.

So, my next test need to be side-by-side comparisons between the AP-22 and the new PerformanceBox.  That will help me consider future runs with the Performancebox in context with the history I have from testing with the AP-22.

I would like to make the tests with Premium fuel and the current, unmodified suspension setup.  So once I have run through a tank of premium I should be able to get the acceleration testing done.  Then I can work on baseline lateral G-force test setup and execution with the base / stock suspension.  Finally, we can re-run the lateral G-force tests with the CTS-V sway bars in place.

My intuition is that I will also need to decide how to handle the runs with regard to roll-out.  Roll-out is the first 10-12 inches that on a traditional quartermile track, due to deep staging, a vehicle can move before it triggers the timing system.  Rollout tends to make a 0-60mph measurement 0.4-0.5 sec faster than if it were an absolute measurement from 0 feet.  Because magazine tests used 0-60 times from their best quartermile time measure, their 0-60mph times also used the same rollout assumptions.  After some thought on the topic I suspect the best solution is to show the data  both ways.  The PerformanceBox datalogger makes it easy to determine the exact time that the car reached around 1 foot of travel, and this time can then be provided as an offset to the data.  So the data can be shown with and without rollout.

Datalogging Dinner, and inital impressions

Dinner Run

Dinner Run Click to Enlarge

Got the RaceLogic PerformanceBox in the mail today.  Not really a good time for a real acceleration run, but I got it setup in the Cadillac CTS.  Out of the box a registration code from the RaceLogic website has to be entered into the Performancebox to enable all features.  That done, I left the unit on and went to pickup dinner.  The unit records to an SD card if available, and the RaceLogic folks were kind enough to toss in a 2G SD card in exchange for taking an online survey on the purchase.  I grabbed the dinner sack, the SD card out of the Performancebox, and plugged the latter in to my PC so I could play with the data file while I ate.

RaceLogic Performancebox

RaceLogic Performancebox (stock image)

Not much fun acceleration or g-force data in traffic, but it was very easy to save off a google earth datafile from the datalogged, and to load the file up in google earth.  This resulted in a nice map plot with my dinner route.  Then I saved off the google earth result as an image (jpg) file and loaded it here.  Fun.

The route varied somewhat in altitude, but we are around 500ft above sea level.  Looks like 6 or 7 GPS satellites were visible at different times during the trip.  The unit acts as a continuous digital speedometer.  Nothing to hit or push to start a data run, as it is logging data continuously.  Just stop to 0 mph, then accelerate to the desired test velocity.  You get an instant readout of summary info on the gadget while in the car, and a detailed data file to analyze back on the PC.

Cadillac CTS-V Front and Rear Swaybars

Cadillac CTS-V Front and Rear Swaybars

Because the unit is a continuous data logger, I am hopeful that it will be an easy tool to baseline lateral acceleration as I upgrade the suspension on my 2005 Cadillac CTS with components from the 2005 Cadillac CTS-V.