Inside wheel is spinning after putting in coilovers.

[Okibi]

Weight transfer is a function of centre of gravity height, cornering acceleration and track width. It has (almost) nothing to do with body roll - a go-kart still gets weight transfer occurring.

I would assume that body roll is a result of weight transfer and its effect on the springs/dampners/tyres/sways etc.

Adding a rear sway bar (increasing rear roll stiffness) is going to want to cock the inside rear wheel up....2) the outside rear gets more weight on it. Tyres have a coefficient of friction that decreases as you put more weight on them. So the upshot is the rear has less grip (and at the same time the front gets more grip because there is less weight transfer going on there) - so you end up with oversteer.

I understand that an after market stiffer rear sway will increase oversteer, because there's more weight transfer to the outside rear wheel and it can "let go". Never doubted that.

Adding a rear sway bar (increasing rear roll stiffness) is going to want to cock the inside rear wheel up

See this is the one bit I don't understand (especially since we're talking about picking the inside wheel up and not about over steer), how does increasing the rear roll stiffness make the car want to cock up the inside rear wheel more? If the rear of the car hasn't rolled as much wouldn't the inside wheel be closer to the height of the outside wheel?

[rascal]

Adding a rear sway bar (increasing rear roll stiffness) is going to want to cock the inside rear wheel up

See this is the one bit I don't understand (especially since we're talking about picking the inside wheel up and not about over steer), how does increasing the rear roll stiffness make the car want to cock up the inside rear wheel more? If the rear of the car hasn't rolled as much wouldn't the inside wheel be closer to the height of the outside wheel?

When you add or upsize a rear sway bar you increase the rear roll stiffness relative to the front. So in the same corner the front will still roll the same but the rear wont, as the rear inside wheel will move more with the rolling body.(cos the ARB wont let it flex to stay down on the road)

Same would apply to the front. If you stiffen the front against the rear then the front inside wheel will lift more in a corner, just that you don't notice it as much because the wheel isn't being dríven, and so doesn't spin up and make itself obvious.

[Okibi]

So you have increased the pitch, the front outside wheel compresses more so rear inside wheel lifts more .. I'm starting to understand!

When you add or upsize a rear sway bar you increase the rear roll stiffness relative to the front.

Just to clarify we're talking about using/removing the OEM rear sway bar here aren't we?

[Matty]

If the rear of the car hasn't rolled as much wouldn't the inside wheel be closer to the height of the outside wheel?

Yes, but you're missing the reference point. Increasing the rear roll stiffness means the rear wheels will maintain their position relative to the body of the car.

But because the front end is soft (and he's made it softer by modifying it), the body is rolling more. So the inside rear wheel is now lifting more. Adding a rear sway bar will just make this worse.

[lightyear]

I understand now that the rear swaybar will make the wheels stay level with the body rather than the road surface. I am getting the nb torsen 3.9 l.s.d anywho. The car is faster than before but you can actually feel the body slowly rolling over the more i go around the corner. You have to understand that i have never dríven anything on a track before, and what i had before was what i had, i just drove it. I must also mention the car is far easier to drive on the limits than before. I can't count how many times i came off before.

[Ted]

I'm with Matty on this one. I wouldn't go to a big rear bar, and possibly go no bar in the interim. But in the original post, you failed to mention what you did with the rear suspension. So you got extra travel on the front, but are you still limited, esp for droop on the rear? If you only had say an inch of compression left on the rear, it will quickly get to the point of lifting the inside wheel.

I will also guess that you have some sort of rollbar (not the swaybar type) across the rear, thus firming up the b-pillars across the car, and possibly across the tops of the rear suspension top mounts too. Where cars had some inbuilt "suspension" with the flex of the body, take that away and suspension workings become more important.

LSD is a great idea, but keeping the wheels on the deck is even more useful I think. I have always tried to get stacks of travel (and droop) in my cars, makes them easier to drive I think unless its drifting you are after in a low powered car.