Roll center location? :iono:

[BRZranger]

Anyone smart / resourceful enough to figure out and diagram where our car's roll center location is on stock, 20mm drop, 1" drop, and 1.5" drop?

[DEnd]

Yeah I'm smart enough to do it. But I'm not gonna... Simply because I don't have the measurements.

[7thgear]

Originally Posted by brzranger

Anyone smart / resourceful enough to figure out and diagram where our car's roll center location is on stock, 20mm drop, 1" drop, and 1.5" drop?

educate yourself and obtain the resources

[speed-wiz]

CG calculation

[SubieNate]

Not the same thing.

[@Art_Mighty]

This is an important topic. In the VW world there was a lot of information about this and parts to correct the roll center for various levels of drop.

Are all of these suspension "vendors" are marketing parts without good R&D?

[SOneThreeCoupe]

My guess is that Sam Strano probably has the measurements and more likely than not the roll center location for both stock and at his ride height. Failing him, there's always Scooby South and Sccabrz192.

Given the fact that nothing has ever been good enough for me, if I had access to one of the cars I'd have all the measurements for you.

[WillRacer1jz]

Look at your lower control arms and imagine a line going from the outboard LCA's going inboard pass there mounting points until they intercept and that's your roll center. Now go get a protractor and go get some measurement.

[DEnd]

Originally Posted by WillRacer1jz

Look at your lower control arms and imagine a line going from the outboard LCA's going inboard pass there mounting points until they intercept and that's your roll center. Now go get a protractor and go get some measurement.

Umm... No.
On the front draw a line through the lca and another on 90 degrees off the strut mounting point. Where these two lines intersect is the instant center (IC). Draw a line from the IC to the center of the contact patch. If you do this for both sides where the IC to contact patch lines intersect is the front roll center.

For the rear draw lines through each of the control arms where the same side lines intersect is the IC. Like the fronts draw a line from the IC to the center of the contact patch, and where the lines for each side intersect is the rear roll center.

[gmookher]

more importantly, whose LCA's correctly address this for cars running more than 20mm of drop?

[BRZranger]

Originally Posted by gmookher

more importantly, whose LCA's correctly address this for cars running more than 20mm of drop?

I don't think anyone's does. After dropping 1.5" i don't notice any negative or unwanted effects.

Reading about Roll center adapter (RCA) on the STI forums, some don't notice any real benefits. Some reports of broken whiteline RCA and some removing them after install.

[DEnd]

Originally Posted by gmookher

more importantly, whose LCA's correctly address this for cars running more than 20mm of drop?

More body roll might actually be a good thing, depending on what the camber change is, the car may benefit from a more aggressive camber curve.

[gmookher]

Originally Posted by DEnd

More body roll might actually be a good thing, depending on what the camber change is, the car may benefit from a more aggressive camber curve.

are you suggesting that up front? I dont see any squatty benefits up front...

[DEnd]

Originally Posted by gmookher

are you suggesting that up front? I dont see any squatty benefits up front...

I don't know the specifics for this car, but typically lowering the car results in an increase of the distance from the roll center to the center of gravity. This results in more body roll. This body roll results in a camber change at the wheels, this may or may not be beneficial. Whether or not it is depends on how the car behaves and which behavior you want at which ever track or corner you are trying to tune for.