I've read some of the oem bushings are spherical encased in rubber, my question is which bushings aren't and are worth upgrading? Any help and advice would be greatly appreciated.

 

This is a good thread here that discusses bushing replacement. Yes, most of the susp bushes are spherical

Theres really not that many bushings in our suspension. These master kits are a good choice when doing a full re-bush

See here: https://www.evolutionm.net/forums/ev...placement.html

 

Thanks, very informative thread. I have a few more questions though. I just installed bilstein shocks/struts with swift spec-r springs, should I get the whiteline bump steer correction kits pn#'s kca390, kca395, and kca388? In the thread someone posted that all the rear bushings are spherical except the toe arm and trailing arm bushings, is that correct? Are there any spherical bushings in the front control arms? Finally, is it a downgrade to just replace all the bushings with poly replacements? I'm not building a track car, but would like to upgrade the car over OEM whenever possible. Thanks in advance for the help.

 

Ive got the KCA390 but not the rack / pinion kit 395. Not sure what the 388 is? Regarding the front arm. The rear bush, i believe is the only spherical there. The other 1 maybe non spherical & of course the ball joint

 

So, the steering rack kit isn't worth doing? The KCA388 kit replaces the rear toe arm bushing. Here is the link https://whitelineperformance.com/col...88-bushing-kit

 

I replaced all rubber bushings with poly, sphericals, or solid as I was doing mods in different areas. A bunch were done at once so I cannot comment on individual bushing changes. My favorite was the rear LCA spherical as the car didn't tram the road nearly as hard anymore. DO NOT replace any of the factory sphericals with poly as it will be a downgrade to the freedom the sphericals offer.

Front:
KCA395 Roll Center Adjust (due to lowering car)
KCA400M Anti-lift/caster offset spherical
W0593 front LCA bushing (do not do this if you get the offset bushing above as it creates stiction in the suspension)
KCA390 steering precision kit

Rear:
KCA388 bumpsteer correction
W0594 trailing arm

Drivetrain:
Solid shifter base and linkage bushings
Torque Solutions 3-pc motor mount (not the 4-piece due to NVH which my car already has enough of)
Torque Solutions driveshaft bushings
Energy Suspension mustache bar & diff mount bushings

 

^^^Good info up there!

Sorry, but i do have the KCA388 (rear bump steer kit) installed. Im not tracking at this time, so the benefits of the roll center kit & all the other bits are not being utilized to their full benefit

 

Just to add, from my countless hours of research. In the rear, the lower control arm inner bushing (connecting to rear subframe) and outer lower control arm bushing (connecting to wheel hub) are both spherical and should be replaced with oem or other spherical bushings only. The shock absorber bushing is not spherical (middle bushing on lower control arm) and can be replaced with whiteline part. Upper rear control arm OEM bushings are almost entirely metal and from my research are not really worth replacing and should last as is for a very long time.
*That covers all bushing that are in the rear

 

IMO KCA390 steering precision kit is worth doing if the car is lowered. It slightly alters the height of the steering rack and reduces bumpsteer that increases with lowering the car. Car will drive better with the kit when lowered, with less tramlining and bumpsteer on uneven road surfaces.

 

I have yet to install this, due to the amount of work it will take to do so LOL. I also have billet spacers to add and longer bolts. I was looking forward to raising my rack a bit.. but, even with the engine out, I was like "f**k it".
Maybe if I get to the point where precious .10s off my lap time matters. Or the engine is out again (knock on wood).