At the SDT day on 16/08/17 a track walk was done from T4 (Gum Tree) to T6 (Siberia). It was very interesting to stand on the track and take the time to have a look around as well as discuss the correct line(s). There was a bit of debate on if T4 is a geometric mid point or very late apex, but in the end it was agreed that the apex can (and should move) based on your car setup as well as grip levels. For me it is a late apex.
Since the resurface of Morgan Park there are not many features that can be used to setup brake points.
This post is looking at where the track walk was done, I'll do the other corners over the weekend.
The red line is my current PB of 01:12.90 and the blue is a 1:13.21 done after the track walk.
T4 Brake - Track position is about the same. The change in the vector G at about 240m is the gear changes.
T4 Turn in - the blue line is carrying a bit more speed. vector G is about the same as is track position. Whilst it does look 'early' the car was traveling at 27.78 m/s, so in 2 seconds straight ahead would have been on the grass!
T4 Apex - much discussion on if this was an early or late apex. I have always treated T4 as a late apex (the screen shot supports this). May have take the 'suggested' line one day. Blue is pulling ahead because of the more speed carried into the corner. Looking at the radius, the blue line is starting to unwind steering whereas the red line is still turning.
T4 Exit - the blue line is a lot further out, and carrying more speed. Steering is almost fully unwound in the blue line, whereas the red line is still winding off steering. The blue line has made much better use of the track!
T5 - speed is the same as is track position. This corner is where you just let the car drift over to the right and try and get the car setup for the hard brake into T6. Whilst the speed is the same due to the blue line carrying more speed it is ahead on time.
T6 brake - this is a hard braking zone and the car should be kept straight when braking hard. This corner is perfect to trail brake on.
T6 turn in - You want to be over to the left as far as possible. Carrying too much speed on turn in will not allow you to nail the late apex.
T6 apex - the apex marker is the drain grate. Trail braking and extra corner speed from T4 has gained 0.4 secs approx so far. However red is now faster in the corner and is still turning whereas the blue line is starting to unwind steering. The corner radius shows this!
T6 Exit - it starts to go wrong about here. The blue line has counter steering on because of lost grip where as the red line is still holding corner speed. The blue line is a lot wider as well. Too much corner speed coming in and not enough trail braking
T6 Exit - The corner radius data says it all, the blue line is still tightening and the red is starting to be unwound. Red is now 11kmh faster.
T6 Exit - Again, blue is still turning and red is acelerating away. The combined G for the blue line has dropped off which means it is not cornering as hard now, rather trying to stay on the track.
T6 Exit - The blue lost almost 0.5 seconds in T6 because of a bad line and a little too much corner speed on entry which resulted in lost of traction and running wide on the exit of T6. However if the speed was held and the corner kept tight it would have been a different result.
