Odd issue that came up, in that the blog went down due to part of a header file disappearing. Easy enough to fix, and I took the opportunity to update to the newer version while I had the hood open anyway. Thanks to Jim for PM’ing me that the page was not loading.
The install files are more than clear on this point, but to mention again an important part of the upgrade process for Wordpress is to disable all plugins before you upgrade. I think that is what might have been giving the upgrade flow issues when I tried previously, or maybe I was just lucky today.
Anyway, technical issue fixed, new blog engine installed, all good.
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.
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.
I am thinking something similar to the Pedder’s Suspension test of the G8 here:
wherein they show both lean angle of the vehicle while cornering and measure g-force attained on a constant radius skidpad. Those seem to be ideal ways to measure performance of the current suspension setup on the Cadillac CTS, then apply mods, and then retest to determine effect.
Also using a tire temperature gauge seems interesting, although only in test consistency.
I have been doing additional customizations with Trackvision to make a ’standard’ acceleration test video overlay to use when doing acceleration tests for Caddyinfo.
This video shows a 0-80 mph data table added to the previous acceleration video:
The ‘with-rollout’ column is calculated by subtracting the time it takes for the vehicle to go 1 foot (in this case 0.99 feet took 0.27 sec in the data file) from the times in order to reflect rollout.
Run was with car hot, low on gas. Regular Unleaded. More to follow.
Update: This video adds live Tach. The performancebox does not data log RPM. For this file I post-processed the data file to calculate RPM based on the Cadillac CTS’ velocity and added it to the datafile before the overlay process in Trackvision:
Here are a single image from a video still captured from my Kodak C875 camera vs the Flip Ultra Series video camera. Hopefully I have done these fairly with justice to each camera. The C875 video has to be processed in quicktime and saved as an H264 image to use with my video software, but I think that the image is not recompressed along the way.
Both are at 640×480 (click on images to see full size):
C875:
C875 Captured off Quicktime by FRAPS and saved to PNG
Flip ultra:
Flip video exported to png image
I think the Flip actually does a better job for use on the web, although it does have some visible compression artifacts. The image appears to be sharper.
Another key factor is that the Flip will capture up to 30 min of video with no intervention. The C875 has an adjustable setting for up to 10 min of video prior to going into power saver mode. The C875 saves to a SD card and can capture up more minutes of video in terms of capacity, but has to be turned back on every 10 min. One fewer thing to keep up with during vehicle testing is better. Both / either appear to work properly with Trackvision.
The C875 is tons better for still images. My thinking now is use the Flip for in car video, and the C875 for session still shots on a tripod.
It appears that the DivX decoder puts up a DivX watermark into the video on some frames, as caught here. Interesting. This may have been an effect of cueing the video to the section I wanted and windows media.
The Detroit Bureau blog has this quote from Steve Shannon (GM Premium Channel Marketing) about the upcoming Cadillac model that will slot below the CTS (Background on “Alpha” Cadillac) :
The project is well underway, he hints, and could reach market “probably in 24 to 30 months.” Beyond that, Shannon goes mum, though he concedes a variety of body styles are under study, including the requisite sedan, and alternatives including a 3-door hatchback, a 5-door wagon and a convertible.
hmm. That appears to make the Alpha Cadillac a 2012 or 2013 model. This is disappointingly slow from my point of view, but may be ‘rapid’ development for GM.
Here was the Motor Trend concept drawing for what the Alpha might look like:
Alpha Cadillac
So we got the new CTS-V and Sport Wagon in 2009, the SRX in 2010. 2011 perhaps will bring the CTS Coupe, then if 2012 the Alpha Cadillac premiers I suppose that keeps the product release momentum rolling along.
We have more parts in place for the Alpha now, with the new DI 3.0 V6 engine released at 260hp, and a nice 2.8L Turbo V6 on the way at 300hp.
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.
The Cadillac Notes blog has a short write-up about the various Cadillac models to be exhibited this week at the NY Auto Show.
Each of the pics shown can be zoomed up to nice 3kx2k hi-res images, so don’t miss that.
I think people are really going to enjoy the new LF1 3.0L Direct Injection V6. It makes the similar power to the non-DI 3.6L engine and should get improved fuel economy. With all the financial gloom some really good work is easy to miss.
The new right-sized SRX could be a real winner.
2010 Cadillac SRX
I think this size Cute SUV is very useful to a variety of Drivers. Offering Cadillac luxury and performance in this category is a great fit.
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 (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
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.
