calvinlc

So for the best handling option on the upper control arms, what is the consensus - del-a-lum bushings in the stock arms or the SPC arms? This is on a '91 Z07 that is mostly a track car, but still driven about 2-3k miles a year on the street. Thanks.
--Calvin

LoneStarV

Researched this endlessly. Track fine. Street? Del-a lum or Delrin bushings will knock your fillings out.

cttech455

I have Del Alum bushings in the upper and bottom arms on my car that I purchased from global west. I'm not familier with the spc arms, but havn't had any problems with what I have.

96GS#007

Del-a-lum bushings are fine for a few thousand miles of street use each year. I ran them for many years in my GS, which until the last few years always saw 3-4k miles of street use in addition to the track....






I'm not familiar with the other arms, but if they're adjustable then the biggest benefit is the ability to dial in more negative camber, which can be a challenge on C4s with otherwise stock arms.

Kubs

For a mostly track car get the SPC uppers and use the Del-a-Lum in the lowers. Having the ability to adjust camber on the C4 is huge like 96GS#007 said.

I designed and built my own uppers to use heim joints because I was not sure what type of bushing/bearing comes in the SPC arms. Also, it was cheaper. I have the Del-a-Lum bushings in my lowers. I have not had it on track yet with this setup though.

93Rubie

How often did you lube them up?

96GS#007

I'd give mine a shot of grease ~ once/year. Over the last 7-8 years I probably averaged 3k miles per year with them....most on the race track.

Kubs

About once a year as general maintenance.

93Rubie

Sounds like they are the ones to put in when I replace mine in the future. I found they make them for the front but I see none for the back. I guess poly then.

I put on roughy 3-4K a year as well. Throw in 15 or so auto-x events and soon a HPDE once or twice a year. They sound perfect.

Kubs

You cannot install this style of bushing in the rear because there is more than one range of motion in most places. These will only rotate in one direction. Your best best would be to get a rod end kit like Banski or the rear will not feel as good as the front. If the front is stiffer than the rear you will get mid corner and corner exit understeer. It is better to have it neutral or slight oversteer.

93Rubie

Yeah, understeer is bad. Thanks. I've worked to get rid of it as much as possible. Not going back, a tad is fine for stability but no more than that.