Body roll is bad

Because muh drivers car

Body roll causes the car's weight to shift to one side, and it doesn't take a genius to work out why that's bad. Because the car's weight is now on one side, the inside wheels now have less traction, and because they have less traction, the differential is now going to send all the power to that wheel, which doesn't need an explanation to work out why that is also bad.

A little bit of body roll is not going to upset the car a great deal, and it's inevitable unless the car has no suspension at all, but unless it's an econobox that's never going to be driven anywhere near its limits, you want the chassis to be as firm as possible and the suspension set up to limit body roll as much as possible.

Very little of the weight transfer in a corner is because of body roll. Much more lateral load transfer is caused by lateral forces created at the tires.

>i don't know how suspension works
Magnetic suspension only affects the dampers, the only advantage is that it can make hard suspension livable rather than punishing. You'd need active suspension to actually do what you say.

CG height divided by width. Suspension tuning is also important to limit suspension rise under cornering, and to limit maximum grip before sliding.
youtube.com/watch?v=zaYFLb8WMGM

...

i've seen more.

Body roll has its purpose, excessive body roll is usually bad, though.

that comfort.

youtube.com/watch?v=09-C33SrJi8

Weight transfer happens anyway regardless of body roll or diving/squatting
Learn how suspensions work.

body roll means the car can be used on bumpy roads and fun to drive.

youtube.com/watch?v=FxrWTZjtCXo

ITT: idiots that talk about vehicle dynamics with no education about vehicle dynamics.

Weight transfer is a function of track width, center of gravity height, lateral acceleration (caused by the tires) and total weight. More specifically, it's:
(CG height x lateral acc x weight) / track width

Notice how there is no mention of roll centers, spring stiffness or anything related to body roll.

The only thing body roll does, related to weight transfer, is to shift the CG a little bit to one side and possibly up or down, which will indeed change the weight distribution and transfer picture a bit, but it's nothing you will ever notice as a driver.

Karts have no suspension whatsoever and still transfer weight just as fine

Body roll depends on CG height, roll center height, total weight, track width, lateral acceleration and suspension stiffness (springs, antiroll bars, tires). It's a consequence of lateral acceleration and it does not cause weight transfer by itself except for that tiny CG movement which is impossible to notice while driving (fuel moving in the fuel tank has a greater effect on CG position, for example).

If the "more roll = more load transfer" logic were true, then karts would not transfer weight at all and race cars, which have a severely restricted body roll, would transfer very little weight. Both things are completely wrong of course.

You don't need to be engineers to get these concepts, go read some actual books instead of getting your physics lessons on YouTube

Weight transfer isn't the only thing that affects grip tho.

If you're at -1.5 deg neg camber at typical ride height, but half the tires move 3 inches in droop when cornering to -2 deg camber, while the other two move 3 inches in compression to +1 deg camber, your grip is still going to be fucked.

G bodies and mk 3 supras both do that last I knew, and the G body will also cause major toe changes on the rear axle in roll, enough to make the ass end start steering the car.

I mean yeah, weight transfer is important, but it's not the only thing to consider when deciding how much roll is going to be acceptable for your application.

Of course suspension geometry plays a huge part, I was mainly referring to all the people saying body roll causes weight transfer, which is only technically true for that tiny CG movement caused by the chassis leaning on one side, which I'm pretty sure was not what all those people meant when saying that.

There was no talk about suspension geometry or how suspension movement affects grip, we would spend all day listing all the things that change the amount of available grip when different cars with different suspensions enter the same curve.

I just wanted to make clear that body roll doesn't cause load transfer in a way that any of us would notice.

>If the "more roll = more load transfer" logic were true, then karts would not transfer weight at all and race cars, which have a severely restricted body roll, would transfer very little weight. Both things are completely wrong of course.

racecars and gokarts to have less load transfer though

Body roll has basically no effect on the magnitude of load transfer - just delays it.

unless your talking about truck race cars.

youtube.com/watch?v=MBKkMt706Ow

we know

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Ok, but it's not a consequence of the absent or minor body roll

I think karts basically derive all their suspension from the tires deforming

Karts also are extremely sensitive to the rear axles (and the whole chassis) flexing. It's their main "spring" and it can dramatically change the behaviour of the kart.
While you can't do much about the chassis, the axles are swappable, they are just hollow tubes and, depending how thick you want the metal to be, it will make a huge difference.

But yes, tires and axles are the only thing resembling a suspension in karts

Someone needs to combine the top half with that gif of the cat and woman wiggling their hips.

>Ideally you'd want zero body roll

Why would you want that

youtube.com/watch?v=iTxKRP-U31I

Body roll is bad, but overly stiff springs and/or an overly strong connection between wheels via stiff swaybar is worse.