Adjustable Endlinks

Any tips on how to configure adjustable end links?

I've heard that the either you should adjust the end links to get no preload on the sway bar OR you should adjust the endlink so that it is perpendicular to the sway bar.

What is the most important?

Thanks in advance

949Racing has a nice video for Miata bar adjustment. The general order is attach your first endlink so it's perpendicular with the ground and the bar is reasonably level, then attach your second end link and adjust until you have no preload and the link can rotate freely. Once the 2nd link is locked in, recheck the first one for preload and you're done. Do all of this with the car on the ground (rotate the wheel for access).

^Right. Preload and angle are two separate things, but separately you have the two goals correct - you want the endlink as close to perpendicular as possible (to minimize bind effects), and no preload (assuming you want unbiased cornering).

Angle can be used to create a rising rate or falling rate for the bar depending on how the rest of the suspension is setup...