jimpactmfsc

iTrader: (5)

hey guys, just wanted to make sure i was understanding things correctly about spring rates.. the oem spring rates are

350Z 2004.5 to 2008
Front:314 Rear:427

and my spring rates

Eibach 350Z progressive springs 1”/1”
Spring rates in LBS initial/final front 296/384 initial/final rear 316/421

314/427 and 384/421 are fairly close, so the eibach pro kit should be ok with stock shocks? thanks

terrasmak

iTrader: (8)

From what i'm looking at, they will wear out the fronts faster then the rear. But the big one is they will wear out both because of the change in piston position in its path of travel. Especially with the seriously dumped Eibach springs.

jimpactmfsc

iTrader: (5)

understood,thanks man

Q45tech

Spring rate [published] can confuse since it MUST be corrected for angle and mounting distance from hub [center of wheel] to arrive at the really important Wheel rate. The wheel rate must be mixed with the tire sidewall stiffness [spring rate] to arrive at the REAL roll stiffness rate.

Most cars have real roll rates of less than 200 pounds to match shocks [+-3"] stroke.
Nissan tends to match springs to front to rear weight ratio. Then use sway bars to induce front understeer.