Polyurethane Rear Upper "Banana" Link Bushings
#40
Love Simard's part. Look what you can do when you are a machinist for a living! Very nice. And a slick way to adjust camber.
Regards the for-and-aft movement question: I have a car in the way in the shop at the moment that should be leaving by Wednesday.
Then I can pull the 91 928 in that is wearing these links and get it up in the air. I'll remove the wheel and the outer attaching bolt, leaving the inner bolt in place. And I'll take pics to show you what for-and-aft movement is available with this setup.
If we find that the for-and-aft movement has too much resistance (remember: I am trying to add resisitance to the system) then I can re-install the conical washer into the system and re-test.
That's the plan.
Regards the for-and-aft movement question: I have a car in the way in the shop at the moment that should be leaving by Wednesday.
Then I can pull the 91 928 in that is wearing these links and get it up in the air. I'll remove the wheel and the outer attaching bolt, leaving the inner bolt in place. And I'll take pics to show you what for-and-aft movement is available with this setup.
If we find that the for-and-aft movement has too much resistance (remember: I am trying to add resisitance to the system) then I can re-install the conical washer into the system and re-test.
That's the plan.
Last edited by Carl Fausett; 11-25-2013 at 11:41 AM.
#42
We've had all kinds of fun with rear camber. Found with the high lateral loads I could turn the camber eccentrics in just a lap or two... they would never hold their position.
So we set the Camber where we wanted it and drilled through and pinned the eccentrics in place with a bolt so they couldn't turn. That did it. I have a picture somewhere of that...
I've also seen the camber eccentric hob out the aluminum in the cross-member because of racing. The wide slot the eccentric turns in got wider and wider as the aluminum wore away. The result was we could get less and less negative camber in the rear. We made a steel cup for the camber eccentric to sit in that fit our cross-member cross-member and that corrected that problem.
Maybe these were the type of things that drove you to adjust camber in the upper link instead.
So we set the Camber where we wanted it and drilled through and pinned the eccentrics in place with a bolt so they couldn't turn. That did it. I have a picture somewhere of that...
I've also seen the camber eccentric hob out the aluminum in the cross-member because of racing. The wide slot the eccentric turns in got wider and wider as the aluminum wore away. The result was we could get less and less negative camber in the rear. We made a steel cup for the camber eccentric to sit in that fit our cross-member cross-member and that corrected that problem.
Maybe these were the type of things that drove you to adjust camber in the upper link instead.
#43
We've had all kinds of fun with rear camber. Found with the high lateral loads I could turn the camber eccentrics in just a lap or two... they would never hold their position.
So we set the Camber where we wanted it and drilled through and pinned the eccentrics in place with a bolt so they couldn't turn. That did it. I have a picture somewhere of that...
I've also seen the camber eccentric hob out the aluminum in the cross-member because of racing. The wide slot the eccentric turns in got wider and wider as the aluminum wore away. The result was we could get less and less negative camber in the rear. We made a steel cup for the camber eccentric to sit in that fit our cross-member cross-member and that corrected that problem.
Maybe these were the type of things that drove you to adjust camber in the upper link instead.
So we set the Camber where we wanted it and drilled through and pinned the eccentrics in place with a bolt so they couldn't turn. That did it. I have a picture somewhere of that...
I've also seen the camber eccentric hob out the aluminum in the cross-member because of racing. The wide slot the eccentric turns in got wider and wider as the aluminum wore away. The result was we could get less and less negative camber in the rear. We made a steel cup for the camber eccentric to sit in that fit our cross-member cross-member and that corrected that problem.
Maybe these were the type of things that drove you to adjust camber in the upper link instead.
P.S. Your problems described above do not help either, luckily we did not encounter them, but I know of cars which have and your solutions sound good...
P.S.1. Latest I got from Kumho Motorsport is that for their V70As to work well, they need more than 2.5 negative camber, and in reality negative 3 degrees and higher. Good luck getting these numbers on a standard 928 suspension...
#44
FWIW the LCA eccentric gets torqued to 140 ft/lbs ,
NOTEmost dont see this as its hard to do with a box wrench on the alignment rack,
thus after a few turns the eccentrics start sliding around in the mounting pads and wear away the shoulders of the adjuster pad.
Pinning the eccentric might be a good option,
as well as adding the Simard adjustable upper control arms.
FWIW I have found many of these LCA bolts loose, bringing a torque wrench to the alignment shop set to 140 is a good idea
NOTEmost dont see this as its hard to do with a box wrench on the alignment rack,
thus after a few turns the eccentrics start sliding around in the mounting pads and wear away the shoulders of the adjuster pad.
Pinning the eccentric might be a good option,
as well as adding the Simard adjustable upper control arms.
FWIW I have found many of these LCA bolts loose, bringing a torque wrench to the alignment shop set to 140 is a good idea
#45
Cheburator: Right - I had a heck of a time just getting the -2 deg of Camber that Hoosier wanted for their slicks.
MrMerlin: in my experience the lateral force pushes the camber eccentric CCW on the LR and that of course loosens itself. I have forced them both to turn when the cornering forces are high enough, but the LR is always the first to go. I could start with -2 deg of Camber - bolt set to spec torque - do one practice session, and you could see the LR was already down on camber when in the paddock.
That's when we started pinning our eccentrics so they couldn't move from where we put them.
MrMerlin: in my experience the lateral force pushes the camber eccentric CCW on the LR and that of course loosens itself. I have forced them both to turn when the cornering forces are high enough, but the LR is always the first to go. I could start with -2 deg of Camber - bolt set to spec torque - do one practice session, and you could see the LR was already down on camber when in the paddock.
That's when we started pinning our eccentrics so they couldn't move from where we put them.