Roll Center moves to other side of the car

[Vicbon]

Hello,

I just want to introduce more discussion concerning roll center point. I know roll center moves in a curve in vertical position and horitzontal as well. I think ... could happens it moves to the other side of the car ... and this would introduce a big discontinuity ??? but how could this affect to the dynamics forces when do you have for instance front roll center right side of the car and rear roll center left side ??

cheers,

Victor

 

[NormPeterson]

I don't think you'd want your lateral RC migration to first go one way for a bit and then double back and go the other way. I suspect that such behavior would be associated with rather large amounts of both lateral and vertical RC migrations.

Regarding RC migration at one end relative to the other - it probably starts at this point regarding reasons that you want to avoid designing front and rear suspensions in their own [separate] vacuums. This goes to driver "feel" and confidence during transient maneuvers even if the steady-state lateral load transfer distribution numbers are reasonable.

Norm

 

[GregLocock]

I think lateral roll centre migration is a fairly benign characteristic, and I'm struggling to think how it would really hurt the car, if it occurred in the absence of any other bad geometry.

The problem I have is that if you have two geometries, and one has lateral roll centre migration, and the other does not, then they will tend to differ in other respects, which I think will dominate.

For instance, looking at the WOB linkage proposed further down the page, moving the body mount one way o the other has no effect at zero roll, but if you roll the car then you'll get a jacking effect. But really that jacking is due to the effective change in roll centre height, not lateral location, in itself.

I agree that the two ends of the car should be designed to move in a similar fashion, generally, but my recent experience with GRCs leads me to believe that you can get away with murder.

Cheers

Greg Locock

 

[maddawg19]

ok ya`ll there are rednecks in here speak clearly NOW......
my understanding of roll center (and i`m still learning) is that it transfers the left side weight to the right side to get though the corners......without the proper roll-center the car will not enter the corner or exit the same lap after lap.....correct or not....?
now what is the best way to check and set roll center and does anybody have a diagram of the exact measuring points

JONES

 

[Vicbon]

Thank you, Greg and everybody for your tips and points of view.

That makes sense Greg that the roll center when migrates to the other side of the car could make a big change in height as well ...

Cheers
Victor