KartPulse Looking at Karting Data - Understanding the Speed Trace: Part 1

Article Information

  • Published By : Davin Sturdivant
  • Published On : Apr 06, 2016
  • Views : 3224
  • Likes : 1
  • Category : Technical Articles
  • Description : So one of the things that I’m going to try to do on these articles, is break down how I’m reading data traces piece by piece, in the hopes that it helps.

Overview

  • One of the concepts that AIM Sports National Training Manager, Roger Caddell mentions in his trainings on Race Studio 2 is the concept of the two “money channels”.  They are the two outputs that all of our analysis is trying to essentially improve as a sum: Laptime and Speed. No matter what we're looking for, we're trying to produce a a lower laptime and a higher speed. 


    Laptime is a pretty easy one, so we’re going to spend a few articles after talking about Speed traces. The speed trace is one of the first places that you can start looking when analyzing your data that's simple, and doesn't require much math. It'll help if you have a data logging system that tracks GPS speed in order to get this, as your data logger will need to know how fast you're going, in order to show speed in the data.

    So first, we'll look at what a Speed Trace is, and how to basically read it. I’ve take a screenshot of a lap that I’ve done of Sumas International Motorsport Academy, in Sumas Washington. I’ve also included a larger screenshot of the trackmap, just for reference. I’m only showing the GPS speed channel in this screenshot.


    Fortunately, speed is a easy channel to start with. On the whole, you can make the presumption that speed traces with a negative slope are when you’re decelerating for a corner (either through braking or via lifting) and traces with a positive slope are when you are accelerating.


    My kart doesn’t have brake pressure sensors, but what I can do is look at where at the rate my kart is slowing down to start to get the initial idea of how I’m decelerating for corners. Notice that I said decelerating, not just braking. There are some corners where you can set up for the entry using a lift of the throttle, rather than braking. You can have a good sense of which corners are braking corners, normally by the rate that the slope of the line of the speed trace, and how much speed you’re shaving. The traces with the larger changes in speed and steep slopes, typically are braking events.

    Now that we have a good sense for those, you also want to look at the rate that you’re decelerating into the corners. If the traces are smoothly sloped down, you can presume that your braking into the corner was nice and smooth. (There are other data traces that we can look at to get an idea for G Force on the kart, but we’ll discuss that in a later article)

    Take a look at the image above. I’ve marked where you can identify the turns via a speed trace from my onboard data. Can you see where the “turns” are identified? I’ve put together a video of the same track below. (This was prior to getting my SmartyCam, so there are no data traces in this video.)


    So here, we've basically discussed "what is happening" and "where is it happening" at a high level. In my next post, we’ll start talk about how to identify what is happening on a lap, just by using the speed trace and how to identify where time is being lost between laps. We'll start talking about the "why".