mx5cartalk.com

I'm no expert so take this post with a grain of salt.

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.

T1 to T3

T1 brake - The 50m sign is a good marker for my set up to start the brake. Stay over as far to the left as possible.


T1 turn 1 - I turn in just after the end of the pit wall. This is actually a fast corner and only a short braking zone.
The blue line is loosing time because I changed before the corner. The red line has the gear change after T1. For my setup it is better for car stability to do the gear change just after the exit of T1. The data supports this logic.


T1 Apex - very late and it is possible to use the kerb. It is a little bumpy just before the apex so take care. T1 is all about getting the car setup for T2, so make it as straight as possible. As the steering in unwinding is when the gear change is done, at this point the car is 'stable'.
The blue line is 'faster' because the car is in a better gear to accelerate with. However overall it is still slower.


T1 Exit - T2 turn in - For me this is almost a constant radius from the apex of T1 to the turn in for T2. Avoid the kerbs on the exit they are brutal.


T2 Apex - very late just before the track layout starts to change. T2 is a bit deceptive as it does tighten up. The kerb is narrow here but can be used. Time to start looking for the exit point


T2 Exit - almost at the end of the ripple strip. Do not go onto the ripple strip, it is teeth jarring! The blue line is starting to claw back the previous time lost due to the higher corner/exit speed.
Depending on the power/grip of your car you start to drift over to the right setting up for T3 (bridge).


T3 turn in - it is best to start the turn in as far to the right as possible. The blue is quickest here because it is traveling less. The key here is keeping on the gas and making for the bridge.
I try and use the tower on the right of the bridge, the moment it can be seen completely I start the turn in.


T3 apex - under the bridge. The red line is faster as starting the turn in wide allowed more speed to be carried through the corner.
This is a 'fun' corner it takes 'faith' to keep the speed up when you cannot see too far ahead.



T3 exit - just as the black bitumen finishes on the ripple strips.
These ripple strips are very jarring so avoid them. Whilst the ripple strips are less sever on the extreme outside when you come back on to the track they get worse. Enjoy this corner and the run down to T4