Safety of long banked corners

[skgoa]

How dangerous are very long and strongly cambered corners (like those on american ovals) regarding high speed impacts and tyre wear? I am asking because I was thinking about the ideal track layout and such a de facto straight would be a great place to put grandstands.
As far as I can tell, the big problem at Indianapolis in 2005 was that they had cut a diagonal pattern into the corner to improve grip for NASCAR and the Bridgestone tyres were fine but ovals (or is it high top speeds?) seem to create horrific accidents.

[flynfrog]

There is nothing wrong with them. Poorly constructed tires on the other hand....

[DaveW]

A little advertised fact is that it took Firestone (Bridgstone) three attempts to arrive at tyres for the grooved Indy surface at the start of the 2005. I believe that even now they produce specific "Indy tyres" even though, I understand, they may no longer be necessary.

I guess the moral is that the surface matters...

[olefud]

How dangerous are very long and strongly cambered corners (like those on american ovals) regarding high speed impacts and tyre wear? I am asking because I was thinking about the ideal track layout and such a de facto straight would be a great place to put grandstands.
As far as I can tell, the big problem at Indianapolis in 2005 was that they had cut a diagonal pattern into the corner to improve grip for NASCAR and the Bridgestone tyres were fine but ovals (or is it high top speeds?) seem to create horrific accidents.

The problem with stands on corners is that cars and car parts travel tangentially, i.e. towards the more distant stands, when control is lost. Most safety provisions seem to assume that the travel is close-coupled to the wall, i.e. perpendicular to the curve. Thus, for instance, a free wheel and tire can bounce and obtain substantial height before reaching the stands – though lanyards appear to be doing a good job. An uncontrolled car also has more room to gain altitude while, unlike a straight, traveling towards the stands.

[flynfrog]

A little advertised fact is that it took Firestone (Bridgstone) three attempts to arrive at tyres for the grooved Indy surface at the start of the 2005. I believe that even now they produce specific "Indy tyres" even though, I understand, they may no longer be necessary.

I guess the moral is that the surface matters...

In the early days of nascar they would grease the tracks to lower the load on the tires so they would last more than a few laps.

[Paul]

It's not too bad as long as it has a fence of sorts, not like this one:

[Jersey Tom]

Banked corners can make for some interesting stuff. In theory and if done right for example, having variable banking as you get up the wall should allow for multiple effective racing lines through the thing rather than one "parade line." In NASCAR you are ultimately forced to have to run different lines at times depending on how your car handles or, if there's traffic.

As far as safety, having a fence on the outside is a must. And from a tire perspective, the increased loading you get can be pretty brutal. I'd wager that in either an absolute or average sense, the right side (and particularly RF) loading you get at the fast, high banked tracks is appreciably higher than anything you'd get in F1 - either peak or on average.

In any event, I like race tracks with even subtly changing elevation and road camber / banking. The really super flat stuff (Sebring, anyone?) not as much.

[FW17]

a look at the abrasive track surface at indy



Comparison regular and diamond grooved surface




Marbles at Indy 2005 on right vs other tracks