Race car suspension Class

[sbrothy]

Wow, I've more or less just discovered racing but man you guys take it to another level altogether!

EDIT: That is one of the things I love about this forum. Suddenly you're reading a discussion about esoteric race car mechanics or train gears or whatnot. Never a dull moment!

 

[Ranger Mike]

Welcome Sbrothy, Thanks for the kind words! Racing is world wide and pretty much universal!
rm

 

[Belbs81]

hey @rangermike had another question for you about rear axle "placement" if we want to call it that. With the panhard bar set on an angle which ever direction a person sets it at for their particular setup, when the body of the car rolls over and loads the axle either pushing down on or pulling down on the panhard bar does that displace the axle to either the right or the left affecting how much "load" the tire is picking up? IE. if the bar is sloped down to the chassis on the right, when the body rolls to the right on a circle track that effectively shortens that bar further, and pulls the axle to the right along with it, which then puts the tire further under the car towards the CL of the car and makes it pick up more of the rear weight. I hope i have explained my thoughts properly here enough to not be too confusing. i just want to make sure i am actually understanding how that particular piece of suspension geometry works, i feel like that is too simple for how it works but just wanted to double check.

 

[Ranger Mike]

Please read post 246 on page 9. post 1643 on page 55.
If you go to the Page number indicator, (has the left pointer and Prev) you will see 3 dots (...)
click on them and type in page!
rm

 

[Ranger Mike]

Panhard bar mounting location

A quick review about the panhard bar. It locates and limits the rear end of the race car form moving sideways in a turn. On paved tracks the panhard bar is anchored to the axel on left side and mounted to the body on the right side. Dirt track cars are the opposite as they need maximum traction on dirt.

On dirt and pavement in a turn with a level panhard bar, the lateral force goes straight sideways and the tires are the only counter to this force.

On dirt and pavement in a turn with a level panhard bar, the Rear Roll Center is exactly where the panhard bar crosses the car center line and usually is NOT the mid point of the panhard bar.

On dirt and pavement in a turn with a panhard bar angled downward to the right rear tire will LOWER the Rear Roll Center. The lateral force is now directed to the right rear tire and placed more download force on that tire and adds traction.

Yes, the Moment arm between the rear Roll Center and the cars Center of Gravity is now longer length, but the force angle is greater on the right rear tire.

On dirt and pavement car raising the Rear Roll Center will loosen the car in a turn.