SundayDriver

I found this to be very fascinating. I think this got missed in another thread, so I thought I would post a new thread.

An Indy car in T1 at Indy has the following ride heights:
F 0.875" R 0.125" down the straight which provides lowest drag. But in T1
F 1.250 R 1.875 for good downforce. Realize this car is now seeing 2+ g's straight down just from the banking, plus the aero downforce.

This car would show the same characteristics on a flat corner as well. There is no active suspension and things like shocks and heim joints are pretty normal stuff.

So how in the world can it raise the ride height under far greater downward forces?

RedlineMan

Tires.

SundayDriver

Nope.

Veloce Raptor

The driver had burritos for lunch?

Barfly

Geoffrey

Mark, I know...

SundayDriver

I kind of suspected you would.

Nice meeting you this week. Has your head exploded yet from all the new information?

Bull

Speed....and the Bernoulli Effect applied to the inverted wing shape of the chassis, lower the car on the straights.

SundayDriver

Nope. Not that either. The speed on the straight vs. corner is not that much different and Indy cars run huge spring rates.

Z-man

I suspect is has something to do with the centripital forces that are acting upon the car. Part of the 2-g's of force is 'lost' in the energy that the car is using to keep turning. IE: The car wants to go off on a tanget - by keeping the car in a circle pattern, all that potential downforce goes off to the side, and can't keep the car as planted as on the straights.

If that is correct, my high school physics teach would be so proud...
-Z-man.

SundayDriver

Sorry, that is not it either. I will add that if you apply the lateral and vertical g forces through the car sitting on a setup pad, pretty much the same thing would happen. The ride height would go higher.

shiners780

Chassis flex?

Where exactly on the chassis are the ride heights being measured?

SundayDriver

It is not chassis flex (that would not raise all four corners of the car).
Height, I am sure, was accurately measured with laser ride height sensors.

I am about to get on a plane so am away from the puzzle for a while.
Hint - It is very intentional in the design of the suspension.

Bull

Hey, I had to take the shot.....I try to use the only Fizzicks I know at least once a year, and it is getting late in the year!

Bull

They are still using a Riley Rocker suspension, right?