Goodwood

[moneymanager]

We were lucky to find ourselves at Goodwood in September for the big annual vintage weekend. Gorgeous venue, vintage clothes on large numbers of guests, and wonderful weather (at least on Sunday.) The racing is as good as it gets. Reminds you that the modern version is the lifeless spectacle that it is. (No wonder the stands are mostly empty.) Take a look at the one hour clip below. No Porsches in this particular event but great racing. Stay to the end or if that's too long watch the start then skip to the half way point for the rest.
If you're hooked on this you can watch the entire Goodwood weekend on their website...about 16 hours of vintage racing!

https://www.goodwood.com/grrc/event-coverage/goodwood-revival/2016/10/video-2016-rac-tt-celebration-full-race/?utm_source=The%20Goodwood%20Estate%20Company%20Lt d&utm_medium=email&utm_campaign=7634878_MSI%20GRR%20October%2014%2020 16&utm_content=TT&dm_i=1QLU,4JN3Y,JU2XXM,GUF8Q,1

[kent olsen]

That was good, old school power and little tires!!

[sugarwood]

The cars seem very squirrely like they're driving on ice

[kent olsen]

They made 400 HP back in those days also but you can see they aren't running race tires but treaded narrow tires. Race rubber makes a tremendous difference plus now adays they would be running 12-15" tires and not 6-7".

[Sicklyscott]

i love watching these guys slide around. So much fun to watch!

[Charles Freeborn]

Here're some early 911's on the same track. I've been known to drift a little, but nothing like this...

[sugarwood]

Those sliding 911's are demonstrating "slip angle", right?
A few degrees of slip actually has more traction?

[Flieger]

Specifically that would be lots of rear slip angle. All (or nearly all) tires use slip angle to generate lateral force, however slip angle is a bit of a misleading term as the best grip is had when most of the contact patch is actually stuck to the road (static). It is the difference between the path taken by the adhered contact patch and the velocity vector defined by the rotation plane of the tire. Lateral force usually peaks somewhere about 6 degrees. Different tire constructions and different tire sizes will have different slip angles for the maximum lateral force. Tall, narrow tires have a lot more deflection and peak at a higher slip angle than low profile tires.

With a rear heavy car the rear needs more lateral force than the front and with the same tires front and back that means the rear means more slip angle than the front. This is called oversteer because with a neutral steer car (equal front and rear slip angles) the steering angle required for a given turn radius is constant. If the rear slip angle increases more than the front as the lateral acceleration builds, this means that the steering must be reduced as the turn is taken faster. In other words, the car would tend to over-steer if not corrected.

Rally style drifting I would consider in a different category than slip angle because there is no real adhesion on a loose surface.

[winders]

Slip does not equal slide....

[winders]

Read this thread:

Moving to the next level driving, mentally... - Rennlist Discussion Forums

[Dave at Pelican Parts]

I wonder if they have bias-ply tires? If so, that would explain why they appear to be sliding to us, who are presumably more used to radial tires. They could be maintaining a larger slip angle than radials would be happy with, which would look something like a slide to me at least...

I suspect a similar thing is going on with that amazing SWB 911 at Spa-Francorchamps video we saw a while back.

--DD

[Charles Freeborn]

What I enjoy watching is the fluidity of the process. They clearly know exactly where the grip is and can dance that line seemingly effortlessly. As said in the narration "mesmerizing to watch".