Positive Caster

Negative Caster



Caster: The tilt of the steering pivot axis from vertical when viewed from the side.
Goal: The stock caster settings are usually pretty good, but if you can, adding a bit more than stock can help with high-speed stability.

Toe-in

Toe-out



Toe: The relationship of the two wheels on the same axle when viewed from above.
Goal: A little bit of toe-out up front can help with turn-in. Too much toe-out, though, can lead to instability, especially under braking.

Deeper Dive
Check out the December 2018 issue of Grassroots Motorsports for more alignment talk.

WHICH PYROMETER: PROBE-TYPE OR INFRARED?

“Most tire engineers prefer the probe type for tires as the probe gets down to the cord,” Longacre Racing Products explains on its website. “At the cord, the tire heat is unaffected by outside factors and the surface rubber insulates the heat for long enough for you to take readings. There is also an elastic stretching of the rubber near the cord that creates heat as well.”