zzyzx

Just curious about something...Racelogic shows a time delta based on either distance traveled or position. Position is the factor that should be used for comparison since the distance traveled could be different between two cars just based on different lines taken.

So my question is if AiM uses GPS position or if they use distance traveled. The software does not give the option of using position or distance, only distance, and I always assumed that by distance they meant not the distance traveled individually be each car each lap, but rather by a set distance from the S/F. line.

ShakeNBake

Most systems (but I could be wrong) use a S/F point for lap time calculations. The option Racelogic gives you is how to reference Y-axis data for comparison between laps - or in situations where there is no lap like a rally segment. Distance can help you understand different nuances - like how much of an impact a shorter line strategy has. Setting the X-axis reference also is how the video gets indexed. For aim users this will blow your mind...sorry. You can do things like, show me where I am at on the track on this lap vs. this other lap, based on my line strategy (maybe a big distance difference). Seeing that in video gets the point across with a little more punch than in just the data traces.

So imagine for all you COTA guys, who, cough......make the esses a little more of a straight line, cough (raising hand to admit guilt when trying to catch that pesky 570S). In video, you can see how much of an impact just purely the distance has on one strategy vs another.

I typically use position...

Matt Romanowski

I have no direct Racelogic experience, but almost all other data systems work on time or distance from start finish. Time is not usually useful because with any time difference, the graphs go out of alignment. Looking at the a speed trace like this is the same idea as the time compare (slip) graph, but not as intuitive or easy to see.

So, normally we work in distance measures. But, just like time, rarely is the distance traveled the same from lap to lap. Most software will then slightly shrink, stretch, or scale the laps so they end at the same place to make analysis the possible. This normally makes all of the analysis much easer, but there are some instances where you can want to turn it off, though that's the 1% of analysis. More important that exact distance covered is lap alignment. Many people are lead down false analysis because they don't have good alignment of their laps.

So, long way of saying that AiM uses distance or time to compare. When in distance, it's feet (well, most likely meters converted to feet) from start finish. In time mode, it's time from start/finish.

But, if someone has AiM and wanted to compare and use the position, it is possible. By going into time mode, then looking at the GPS graph, you'll see the two marks of where the car is on each lap. Then you can use the snap function to allow you to shift one lap and get the marks to be in the same position. If you wanted to see the video shot of that position, then you could be able to use the scales on the bottom to go to that time in the SmartyCam video and see the view from the car. Certainly not as easy, but doable.

I personally use the data to identify the areas for improvement or analysis, then use Comparemylaps.com to jump into the videos in those corners. I don't really care what the exact coordinate position of the car is, but rather the relative position oof the car on the track surface and the heading of the car. Many times the difference in fast and not as quick laps is in the angle of the car approaching and through the apex. We don't need a coordinate position to do that analysis in my experience.

Sorry for the long winded response, but thought the analysis technique behind some of this was important to understand the answer and how to use it.

ProCoach

Thanks for the great explanation, Matt. Good stuff.

Racelogic offers comparison based on time, distance or position.

If you make a study of the comparison of speeds between lthe SAME aps based on distance versus position, you can see the "stretch or shrink" introduced by the analysis software trying to reconcile the difference in position. Interesting stuff.

In the graphs, and even the maps, I don't think there is much of an issue with the standard approach, but with synced video TO GPS POSITION, it's another matter.

I've enjoyed CompareMyLaps. It's allowed me most recently at Road Atlanta to really help a few drivers equipped with AiM. But it is a workaround to an easier solution, perhaps one that will show up in RS3 Analysis someday?

For the type of analysis I have experience with VBOX, the comparison based on position is MOST important to justify exactly the heading and lateral position of the car at approach, at apex and at exit of a corner. Of course, this is all related to the driver's belief system allowing them to commit more fully to throttle, brake and steering.

After using exact coordinate positions to compare video, throttle, brake, steering, heading and auto-synced video between two or more laps, it's very hard to go back to the conventional distance or time based comparisons present in nearly every other low, medium or high end data acquisition system.

This is why in private coaching, I make sure to add a VBOX HD or HD2 to whatever system the car has on it. Simply the quickest and most accurate way of doing what you are trying to do in your last paragraph, in my experience.

zzyzx

It's a good thing I don't use AiM anymore. So, if didn't know that AiM uses "distance" as distance traveled by the car from the S/F line, not distance as in a set distance from the S/F line, then you would get all kinds of things wrong in your analysis.
You could look at car A and see that it's braking 20 feet earlier for a turn, when in fact it's braking at the exact same point as car B, only that car A has been driving a 20 ft greater distance on the course previous to that point.
Sounds like AiM is as lap timer and segment timer, and not much else.

Matt Romanowski

Any system that uses distance, it is distance from start finish. Prior to GPS, it was based on roll out and wheel speed. With the addition of GPS, it used that and was much more accurate. Now with a decade plus of GPS development, they are doing even more.

Sorry your experience with AiM was not good, but I think you will find no system is perfect. It sounds like you have something you like now and I hope you get the support and results you want.

mglobe

zzyzx

Yeah, at the risk of sounding like I'm making paid endorsement, I'm very happy with Racelogic. I'm only using their most basic system, but I'm looking forward to upgrading to one of their video/data loggers next year.

ProCoach

ProCoach