kmagvette

Dedicated track car needs some updating.

Looking to replace control arms and knuckles with whatever is strongest.

I have heard that the C6 knuckles are stronger and work fine if you have coil-overs; I do.

Anybody have experience with C6Z control arms on the C5? Obviously the rear uppers are out without grinding, welding, and drilling.

Ideally I would like these without bushings as they will be getting either Delrin or Poly.

As always, thanks for your thoughts.

argonaut

I can confirm that the C6 knuckles fit, just replaced all 4 on my C5 with C6 versions.

0Randy@DRM

Rear upper control are a no go.

Randy

geerookie

the spindles/knuckles are the only direct fit that I know of.
The caliper mounting bosses are stronger which was done to help reduce the pad taper on the ZR1 brake pads.

I have swapped mine and it was a direct swap but required a toe adjustment.

The rear lowers require the C6 cradle, I don't have any specifics on the front but I doubt it's worth the expense or effort.
Spherical bearings would be a better investment.

theseal

dont do anything until i post some data i am working on geometry differences but until then suffice it to say the c5 geometry is radically better.

kmagvette

The motivation for the ask was to get new metal and ball joints on the car. I have not heard of lower control arms failing, but the price of the replacements with new ***** seems to be reasonable considering that I avoid screwing around with BJ replacement...on the other side I need to remove the rubber bushings.

The knuckles seem like a good move since the C6 version is stiffer, should reduce taper, and get a new BJ at the same time.

Geerookie, thanks for the reminder on the rear lowers, I seem to recall hearing that, probably from you, before. It would be nice if the front lowers were a replacement.

Perhaps replacing the lowers on a dedicated track car is pure paranoia. Seems like a reasonable thing to do if considering the cost of delrin or sphericals but I really do not have any data on how/if these things fatigue over time with really sticky rubber.

argonaut

Lower ball joint replacement is utterly simplistic if you have a press. I don't know that the arms fatigue over time but they do deform. I just installed sphericals on a 99 and every single arm needed some adjustment to get them to fit - spread the arms, compress the arms, open up the mounts, etc.

kmagvette

Well, I bought new ZR1 knuckles and lower control arms for the front, everything bolted right up. On the LCA's I did a test fit before ejecting the stock bushings and installing Delrin. With the stock bushings everything looked good.

drivinhard

Front stuff should interchange, rear lowers and uppers are different. Spindles can swap as already said.

Bill Dearborn

Keith,
Do you have the car back on the track?

Bill

kmagvette

Yep, WGI last week with the new massive brakes (25mm+ pads). Everything was great except tire issues...my dumbAss just figured that my spares on C5Z rears would fit up front....nope. Needed 3/8" of spacers and wheel was almost off the hub, so that was not going on the track. Have my spares all on CCW's now.

With the stiffer uprights I had no sign of longitudinal taper.

Headed back next week with Phoenix. Looks like rain. My C6Z fronts fit with 1/8" spacers so the rain setup is good to go.

0Anthony @ LGMotorsports

If you ever want to body the car as a C6, just put in the C6 rear cradle and upper and lower control arms and it will move the wheels to the correct location for the C6 wheel base....FYI.