C4 rear suspension binding? Fixes?
10-31-2008, 09:24 PM
#1
Le Mans Master
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St. Jude Donor '03 & '05
C4 rear suspension binding? Fixes?
I hear allot and defintiely feel it when driving. But the rear suspension with Poly bushings bind up, and the suspesnion doesnt move as freely as it should( Granted, 3300 punds moves it, but with binding/friction). Now the spindle rods (4 of them) are pretty darn tight in the DRM brackets up the frame. Can I shave the bushings down on the sides so they fit in there better? Or is it just live with it and grease it often.
Also, the camber rods are pretty snug too, more so due to the torque of the nut/bolts to keep the alignment in place.
Also, the camber rods are pretty snug too, more so due to the torque of the nut/bolts to keep the alignment in place.
11-01-2008, 09:12 AM
#2
I replaced the old factory rubber bushings with poly and noticed the same thing. The only solution I know of is to go with heim joints/rod ends for the 4 trailing arms & camber rods. If you add the seals it rod end rubber "caps" that should keep the dirt & grit out extending their life.
11-01-2008, 12:02 PM
#3
Pro
The hole in the poly bushing needs to be chamfered, or conical shaped so the openings on both sides are larger than the middle of the hole. This allowes the bushing to move around the bolt without binding. I did this several years ago and it stopped the binding.
11-01-2008, 12:31 PM
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Le Mans Master
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St. Jude Donor '03 & '05
How much dow you chamfer. And did you do camber and spindle rods?
Pics?
11-01-2008, 08:58 PM
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Here's a recent pic of my stock suspension, you can see the old stock rubber bushings binding up so much that they are being forced out.
vs Heim ( not mine, TBD this winter )
His review:
Car feels great. It really freed up the rear suspension. The car actually dropped a bit due to less binding, yet I did not adjust the ride height at all. I scraped my exhaust for the first time after backing out of my steep driveway. (Car is lowered.) I can articulate the rear knuckle easily by hand when the car is on jackstands.
Going over speed bumps, I hear the front end squeak and bounch with the poly bushings. Rear end is quiet as a mouse and transmits less to the chassis.
Took it in the twisties, but improvements there are going to be impossible to quantify without lap times.
I don't know when my next track day is, but I'll have to repeat a track that I've been to recently and compare. May not be until a few months from now when it cools off.
.....
Everyone (without these installed) seems to think they'll ride very rough.
If anything, I found the opposite to be true. Now my car has never rode very smooth, but with the new Bilsteins and these installed, it's as good as ever. I had poly bushings on prior to this, and petrified stock rubber bushings on before that.
I'm not convinced how spherical rod ends can hurt ride quality, when you can easily articulate the suspension by hand, that means the suspension can react quickly to an uneven road surface. The stock pieces in their bound up state are very stiff and hard to move, and so they would transfer more energy directly to the frame, not allowing the suspension to soak it up.
Going over speed bumps, I hear the front end squeak and bounch with the poly bushings. Rear end is quiet as a mouse and transmits less to the chassis.
Took it in the twisties, but improvements there are going to be impossible to quantify without lap times.
I don't know when my next track day is, but I'll have to repeat a track that I've been to recently and compare. May not be until a few months from now when it cools off.
.....
Everyone (without these installed) seems to think they'll ride very rough.
If anything, I found the opposite to be true. Now my car has never rode very smooth, but with the new Bilsteins and these installed, it's as good as ever. I had poly bushings on prior to this, and petrified stock rubber bushings on before that.
I'm not convinced how spherical rod ends can hurt ride quality, when you can easily articulate the suspension by hand, that means the suspension can react quickly to an uneven road surface. The stock pieces in their bound up state are very stiff and hard to move, and so they would transfer more energy directly to the frame, not allowing the suspension to soak it up.
