Where to use rubber bushings? (FC)
Where to use rubber bushings? (FC)
I'm sure you're all tired of bushings threads, but i have a very specific question which has proven difficult to search for.
Obviously it's cheap and easy to get a polyurethane master bushing kit, but from what I understand some of the joints on the rear trailing arm articulate on two planes rather than one. It would seem that urethane is the wrong material for such a joint, and the bushing should be replaced with either rubber or a heim joint. Seeing as my car is still a street car, i plan on getting a rubber bushing.
Which bushings in the suspension should remain rubber? Should bushings be changed simultaneously with the springs and shocks to prevent damaging any components?
Obviously it's cheap and easy to get a polyurethane master bushing kit, but from what I understand some of the joints on the rear trailing arm articulate on two planes rather than one. It would seem that urethane is the wrong material for such a joint, and the bushing should be replaced with either rubber or a heim joint. Seeing as my car is still a street car, i plan on getting a rubber bushing.
Which bushings in the suspension should remain rubber? Should bushings be changed simultaneously with the springs and shocks to prevent damaging any components?
What year is your car? FD I'm assuming? This is relevant. Please note there are aftermarket spherical bushings for the rear trailing arm on the FD that replace the stock pillow *****.
Says FC in the title. 1989. Sorry if that wasn't clear. I'd put it in the OP but i'm no longer allowed to edit it.
I'm also trying to stay away from spherical bushings, as the car will see far more street use than track use.
I'm also trying to stay away from spherical bushings, as the car will see far more street use than track use.
you really shouldnt use urethane anywhere that moves. either stick with OEM, or go delrin/spherical.
OEM bushings dont slide, they flex. when an arm moves, it acts as a small spring, but there's no friction (coulomb damping). because they flex, then can move in multiple axis. theres also some compliance.
Delrin slides, but has a very low friction coefficient. and its damn near solid (no deflection). these can only move about one axis.
urethane also slides, but has a much higher friction coefficient than delrin. it also has compliance like an OEM bushing, although not nearly as much. these also only move about one axis
sphericals are the closest thing to solid, have low friction, and can articulate in multiple axis. they wear faster than the rest though, as i'm sure you're aware.
Front control arm:
go with delrin in the front, and urethane or OEM in the rear. cant do delrin back there unless you cut the barb off, and i dunno if anyone makes delrin for that.
Rear control arm:
spherical or OEM. the arm moves in multiple axis! dont put urethane or delrin in there.
sway bars:
OEM bushings slide on these, so anything will be better. urethane is fine, delrin is better.
For the subframe/diff bushings, put whatever you want. they dont move, so the material doesnt matter. stiffer = more NVH.
OEM bushings dont slide, they flex. when an arm moves, it acts as a small spring, but there's no friction (coulomb damping). because they flex, then can move in multiple axis. theres also some compliance.
Delrin slides, but has a very low friction coefficient. and its damn near solid (no deflection). these can only move about one axis.
urethane also slides, but has a much higher friction coefficient than delrin. it also has compliance like an OEM bushing, although not nearly as much. these also only move about one axis
sphericals are the closest thing to solid, have low friction, and can articulate in multiple axis. they wear faster than the rest though, as i'm sure you're aware.
Front control arm:
go with delrin in the front, and urethane or OEM in the rear. cant do delrin back there unless you cut the barb off, and i dunno if anyone makes delrin for that.
Rear control arm:
spherical or OEM. the arm moves in multiple axis! dont put urethane or delrin in there.
sway bars:
OEM bushings slide on these, so anything will be better. urethane is fine, delrin is better.
For the subframe/diff bushings, put whatever you want. they dont move, so the material doesnt matter. stiffer = more NVH.
