A little blip not related to nationals, but I was blown away when I overlaid these two runs, it's a Mini cooper but it's still crazy relevant to analyzing your autox runs and putting down a fast time.
tl;dr I am just realizing how awesome comparing videos of two co-drivers can be for finding a few tenths of a second out on course, I hope some of y'all co-drives from nationals post up comparison videos as well.
Edit: and as always, apologies for the awful audio, I should really invest in a camera that can support an external mic...
Crank up the quality to 1080p and if you didn't know already you can frame-by-frame youtube with the comma and period buttons on a computer. (You don't even have to go to the site as long as the youtube player is what's active, i.e. you can stop-start with the spacebar)
Top driver ends up ahead with a 47.3 to the bottom driver's 47.6
[ame="https://www.youtube.com/watch?v=w19dz7JqwF0"]Golden Gate Lotus Club Autocross Marina 09-09-2017 Mini Cooper S F56 Bill vs Brian - YouTube[/ame]
The videos were synced on the first apex cone on the left, just as it disappears out of frame. So some quick analysis, bottom driver has a sloppy start and you can see at the first element at speed (cones on the left) and into the turnaround the top driver has a few feet of lead. However going around the turnaround the bottom driver holds a tighter line and digs some of it back around the roundabout and headed into the slalom where they are practically neck and neck. This slalom was optional however the exit made it a total no-brainer which was faster because the other side requires you to slow down an immense amount to get around the final cone and pointed down the straightaway, if you don't believe adding distance is killer to time skip to the end, freeze frame it, and see how much distance a 0.3s time differential is, and realize it shrinks when you don't have a dinky slow finish.
So on the exit of the slalom I believe the bottom driver gets a better exit and drive into the back straight away, frame by frame you can see the earlier setup and turn in by the bottom driver who is holding a tighter line vs. the top drivers wider line, the top driver had to feed in more steering angle to get tight to that cone while the bottom driver was already feeding in the power allowing a bit of wheelspin to let the car drift out (understeer) around the cone. Whatever time was lost on the start and through the slalom by the bottom driver was all back due to holding the line tighter in a few places and setting the car up to get back on the gas as early as possible.
Then into the turnaround, this is where bottom driver blows it, too much steering angle on entry causes the car to plow and lose a ton of speed, once it hooks the bottom driver has to unwind to correct his arc through the turnaround costing even more speed, the exit apex is blown on the turnaround and it's all over, the car is out of shape while the top driver is getting power down and unwinding the steering wheel the bottom driver is trying not to plow over a bunch of cones. Frame-by-frame makes this painfully obvious what the mistakes are.
Both drivers are too wide around the next turnaround, a tighter line would have paid off here, bottom driver is a little tighter on exit than top driver but it's not enough. Both drivers plow around the finish with the bottom driver repeating the exact same mistake as the turnaround but the top holds a tighter line with less steering angle gaining even more time across the finish carrying much more speed.
Stepping back I'm sure there's plenty to critique on both drivers making mistakes, hours could be spent picking it all apart, I'm just incredibly impressed how similarly we both drive this car for better or worse. It can be hard to tell what the mistakes are unless you can sync up what's right on the same screen.
I bet there was a medium 46.x time in that car on that day without any changes. For reference top time of the day was a 44.0s time in a GT-R on Hoosier A7's, a Porsche GT4 put down a low 45 on RE71R's iirc. I'm certain some well prepared cars with top tier drivers could knock that down further but it's incredible how quick you can be with some sweat and determination (and to be fair, there's quite a bit of money into this Mini, although on 205-50-16 RE71R's that are practically treadbare there's lots of room for improvement).
If you're working with other 86's trying to get quicker, put your cameras in as close to the same spot as possible and trade videos. I did the syncing with the free version of Race Render, the first time I messed with it I spent maybe an hour or two, I matched up this video in about 15 minutes and have probably spent at least an hour frame by framing it.
Also, look ahead. I finally managed to do it a few times yesterday and it's amazing how much easier it is to drive the course when you are legitimately looking not at the element coming up but the element that's 3rd or 4th away. With the camera as I have it posted on the left turns I want to see at least the tip of my nose well before I enter that turn. It also becomes obvious how a driver can create a handling problem, the bottom driver could hop out of the car and say "that's an understeering fwd pig" but the reality is that any car driven that aggressively into a corner would have understeered, whether it was a perfectly setup FR-S or 911 or Corvette, too much steering angle, too much speed, not enough grip.
I hope someone finds this useful
