Sprung vs. Unsprung Weight ????

[El_Guapo]

So I recently purchased a set of Z32 rear uprights for a really good price for my S13. I had been doing some research on them and came across a write-up where it stated that the rear uprights save roughly 7-8lbs unsprung weight.

So I was wondering if someone could give me a little info on sprung vs. unsprung weght?



Ivan

[Epstein]

Sprung weight is anything that bounces around on the springs, basically. The upright is connected to the wheel which is connected to the road and therefore is weight not suspended by the spring. It's "unsprung". Making the uprights lighter is still mass taken off the car. Qualifying it as unsprung just tells you where it's coming from.

....and that upright spec is wrong. Together, they will save 7-8 pounds total.

[El_Guapo]

Sprung weight is anything that bounces around on the springs, basically. The upright is connected to the wheel which is connected to the road and therefore is weight not suspended by the spring. It's "unsprung". Making the uprights lighter is still mass taken off the car. Qualifying it as unsprung just tells you where it's coming from.

....and that upright spec is wrong. Together, they will save 7-8 pounds total.

Awesome, thanks for cleraring that up for me. As for the weight difference I read the write-up wrong, I just checked it and it said......

"7-8 lbs. less (unsprung weight) than their S13 counterparts."

my bad

[RanciD]

Unsprung weight is important because it's the weight that the suspension has to control. The less of it there is the easier it is to control.

[Def]

Actually, the suspension DOESN'T directly control the unsprung weight, so that's why it's best to keep it as light as possible.

[MilanT]

The problem with unsprung weight is that its bouncing on the spring rate of the tire. Tires has very little damping so as unsprung weight increases, contact patch load variation also increases.