I was just looking at some PDR data from the 5BW and thought I'd share a bit of it as it relates to handing. This first chart is the Lateral and Longitudinal Gs plotted on an X/Y chart. The colors are tagged to different parts of the corner:
Blue: steady cornering
Purple: steady cornering at high speed (>70 MPH)
Green: Accelerating out of the corner
Red: Braking
Orange: Trail braking (braking and cornering)
The yellow ring is 1G and the outer ring is 1.5G, this is also a plot of all 8 laps in the session.
So what's cool is that this car is pulling nearly 1.5Gs on the factory PS4S tires with peaks near 1.7G. That's damn impressive for a fully treaded street tire on a 4100+ lb sedan.
Now let's look at balance. This is lateral acceleration plotted against a channel I call "oversteer angle". OA is basically the relationship of yaw rate to steering input with positive being oversteer and negative being understeer. In this case I'm only looking at a single fast lap as it's easier to pick out with fewer data points. You see values for right hand turns in the cluster on the left side and left hand turns on the right cluster. It's also worth noting that you always get some degree of understeer when you first turn in as the tire builds slip angle
As a driver I'm most happy in the +/- 5 range. What you can see in this plot is that there is some understeer in corning but it's nothing I'd call horrible with a lot of the understeer coming from picking up the throttle (green) and unweighting the front end. If I pick points of high understeer and go look at the video it's often the entry to Oak Tree (VIR) where I tend to overcook the entry or pickup the throttle early - in other words it's driver inducted. You can also see that by trail braking you can get the cornering pretty neutral - easily balancing between mild understeer and rotation.
I don't know if you all find this nerdy stuff as fascinating as I do but I thought I'd share.
Blue: steady cornering
Purple: steady cornering at high speed (>70 MPH)
Green: Accelerating out of the corner
Red: Braking
Orange: Trail braking (braking and cornering)
The yellow ring is 1G and the outer ring is 1.5G, this is also a plot of all 8 laps in the session.
So what's cool is that this car is pulling nearly 1.5Gs on the factory PS4S tires with peaks near 1.7G. That's damn impressive for a fully treaded street tire on a 4100+ lb sedan.
Now let's look at balance. This is lateral acceleration plotted against a channel I call "oversteer angle". OA is basically the relationship of yaw rate to steering input with positive being oversteer and negative being understeer. In this case I'm only looking at a single fast lap as it's easier to pick out with fewer data points. You see values for right hand turns in the cluster on the left side and left hand turns on the right cluster. It's also worth noting that you always get some degree of understeer when you first turn in as the tire builds slip angle
As a driver I'm most happy in the +/- 5 range. What you can see in this plot is that there is some understeer in corning but it's nothing I'd call horrible with a lot of the understeer coming from picking up the throttle (green) and unweighting the front end. If I pick points of high understeer and go look at the video it's often the entry to Oak Tree (VIR) where I tend to overcook the entry or pickup the throttle early - in other words it's driver inducted. You can also see that by trail braking you can get the cornering pretty neutral - easily balancing between mild understeer and rotation.
I don't know if you all find this nerdy stuff as fascinating as I do but I thought I'd share.
I'm a guy who does occasional HPDEs, as a opposed to a track rat, but a while back I had a JDM Honda Civic Type R (FD2) that was absolutely made for trail braking and I guess I think of it being more to get FWDs turned in, now I am super interested to see how the 4BW will behave with a bit on circuit. Thanks again
and that's looks great, but you may want to close your shades... you don't hear any helicopters do you? 
