Let's see your data - early versus late apex
06-26-2010, 08:49 AM
#46
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06-26-2010, 09:16 AM
#47
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06-26-2010, 09:19 AM
#48
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Patrick, I think I do get your questions. First, you realize, in that middle graph, braking is up (above the X-axis) and acceleration is down. Also, that data is measured from accelerometers - not brake pressure and throttle position like the other people's screen shots. But, it's showing pretty much the same thing.
So, back to your comments. You're right - the red car does, at times, carry more speed into the corners. Like you said, faster into the corner. But, because of the line the red driver choose, the red driver was not able to get the the gas as soon (because the weight transfer to the rear, and reduced steering ability, would place the car on a trajectory that goes off track). The red driver has to scrub off the speed later in the corner to maintain cornering force and direction.
Because of the nature of that track and the turns/straights, we can use the "time difference" or "time gap" plot to look at which has the advantage. In my example above, the red driver gains 0.1 seconds on the red driver by going into the corner fast. However, the blue driver gains 0.3 seconds by getting on the gas soon. The delta of 0.2 seconds in several corners can add up quickly.
Now, in a racing scenario, you have to use all of this knowledge to quickly make decisions. If you're trying to pas a car with equal or less HP/weight, a "dive bomb" pass into a corner might be best, because you can gain on him going into the corner, he has to slow down to the speed you're going, you both come out slow, but you're in front.
If you have a slight HP advantage over a competitor, a better passing situation might be turning in late, getting on the gas early, and using that momentum to pass coming out of the turn.
Sometimes you make decisions based on what your competitor is doing at the moment... This spring, at Lime Rock, I had been following DanR for a lot of the race. I was behind him while he came up on a slower car. He was NOT setting up to be in a position to pass, I realized he'd have to slow down more than normal to go the other car's speed around the corner, so I set up to go faster into the corner, which got me in front of him.
So, back to your comments. You're right - the red car does, at times, carry more speed into the corners. Like you said, faster into the corner. But, because of the line the red driver choose, the red driver was not able to get the the gas as soon (because the weight transfer to the rear, and reduced steering ability, would place the car on a trajectory that goes off track). The red driver has to scrub off the speed later in the corner to maintain cornering force and direction.
Because of the nature of that track and the turns/straights, we can use the "time difference" or "time gap" plot to look at which has the advantage. In my example above, the red driver gains 0.1 seconds on the red driver by going into the corner fast. However, the blue driver gains 0.3 seconds by getting on the gas soon. The delta of 0.2 seconds in several corners can add up quickly.
Now, in a racing scenario, you have to use all of this knowledge to quickly make decisions. If you're trying to pas a car with equal or less HP/weight, a "dive bomb" pass into a corner might be best, because you can gain on him going into the corner, he has to slow down to the speed you're going, you both come out slow, but you're in front.
If you have a slight HP advantage over a competitor, a better passing situation might be turning in late, getting on the gas early, and using that momentum to pass coming out of the turn.
Sometimes you make decisions based on what your competitor is doing at the moment... This spring, at Lime Rock, I had been following DanR for a lot of the race. I was behind him while he came up on a slower car. He was NOT setting up to be in a position to pass, I realized he'd have to slow down more than normal to go the other car's speed around the corner, so I set up to go faster into the corner, which got me in front of him.
06-26-2010, 09:26 AM
#49
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First off, you'll be better off looking at your data as "distance based". Most people are interested in where they are in relation to a data set. Time based data can show you great things like "overall time at full throttle" - if you're on the throttle 40% of a lap, and you can raise that up to 44%, you'll have a big decrease in lap time.
Second, use the zoom feature to look at individual segments, as opposed to a whole lap at once. The way you have it shown, we can't see distinct resolution of things... like your braking pressure.
3rd, a single lap's worth of data is somewhat useless, because it's "in a vacuum" - meaning there's nothing to compare it to. Try overlaying multiple laps - either laps you want to compare, or several of your best laps to look for consistency.
Second, use the zoom feature to look at individual segments, as opposed to a whole lap at once. The way you have it shown, we can't see distinct resolution of things... like your braking pressure.
3rd, a single lap's worth of data is somewhat useless, because it's "in a vacuum" - meaning there's nothing to compare it to. Try overlaying multiple laps - either laps you want to compare, or several of your best laps to look for consistency.
06-26-2010, 12:34 PM
#52
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guys - we're not talking about some noob early apexing and driving off the track. we're talking about two different lines through a corner, one with steering input all the way to track out due to an EARLIER apex and one unwinding earlier with less scrubbing post-apex due to a later apex.
06-26-2010, 01:02 PM
#54
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Gary,
Totally agree with Van, I'm a relatve noob at this but I have found you have to process the data to focus on a particular issue, and it is really about comparisons to a baseline, ie a really fast overall lap or a sector or corner that you are specifically working on. I have good data for this exact discussion but it takes a bit of work to set up the track map/sector/graphs. For this discussion you want two comparison runs on early one later, position based on time on the map, lateralG, longG and speed on the graph, brake and accell plots would be good on separate chart.
A really useful tool is the sector chart to identify speed and time in/out of a corner compared with the position on the track and apex.
Totally agree with Van, I'm a relatve noob at this but I have found you have to process the data to focus on a particular issue, and it is really about comparisons to a baseline, ie a really fast overall lap or a sector or corner that you are specifically working on. I have good data for this exact discussion but it takes a bit of work to set up the track map/sector/graphs. For this discussion you want two comparison runs on early one later, position based on time on the map, lateralG, longG and speed on the graph, brake and accell plots would be good on separate chart.
A really useful tool is the sector chart to identify speed and time in/out of a corner compared with the position on the track and apex.
06-26-2010, 01:13 PM
#56
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06-26-2010, 01:18 PM
#57
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06-26-2010, 01:27 PM
#58
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06-26-2010, 02:06 PM
#59
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06-26-2010, 02:10 PM
#60
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I just have one piece of advice for the Glen. When at Mr. Chicken the order is "1/2 chicken dark".
And Sean and I have proven that if you come into Mr. Chicken hot and brake late you can order, eat, and be out of there in 16.3 minutes.
And Sean and I have proven that if you come into Mr. Chicken hot and brake late you can order, eat, and be out of there in 16.3 minutes.