New and Improved Upper A Arms with Ball Joint
#17
Developer
Thread Starter
You do not need any shims to install these a-arms. If yours are still clean and as-purchased, I'd say let us upgrade them for you. But the coice is yours, the old style does work. I drove on them for 2 years.
#18
Intermediate
Join Date: Dec 2007
Location: Tampa Fl. and Trinidad
Posts: 47
Likes: 0
Received 0 Likes
on
0 Posts
I really like the look of these A arms and am putting them on my mod wish list but! I have two questions to all that have purchased these new upper a arms.
1. Have you noticed a decrease in ride quality due to the fact there is no rubber cushion.
2. Have you notice an increase in precision of handling from these A arms.
Take into account that this will be on a street, regularly driven car.
Thanks in advance for your input.
Allen T.
89 928 5speed hybrid
1. Have you noticed a decrease in ride quality due to the fact there is no rubber cushion.
2. Have you notice an increase in precision of handling from these A arms.
Take into account that this will be on a street, regularly driven car.
Thanks in advance for your input.
Allen T.
89 928 5speed hybrid
#19
Developer
Thread Starter
There should be no decrease in ride quality - the rubber bushings on the ends of the a arm do not effect smothness of the ride, but were put there to further isolate road vibrations from the chassis.
You will be able to set the camber where you want it - and it will stay put inspite of loading on the upper a arm because the rubber bushings have been eliminated. So turn-ins are more immediate and accurate, because there is no rubber bushing that must be compressed before the load can start to transfer.
Results in both regards similar to the popular polyurethane upper a arm bushings.
Difference between this and poly upper a arm bushings: they are very "tight" and it takes effort to move the a-arm up and down after installation. The bushings on ours are smoother (and greasable) and allows the upper a arm to locate with less force. And you get a new ball joint.
I'll shut up now and let folks with poly bushings or our steel upper a arms answer.
You will be able to set the camber where you want it - and it will stay put inspite of loading on the upper a arm because the rubber bushings have been eliminated. So turn-ins are more immediate and accurate, because there is no rubber bushing that must be compressed before the load can start to transfer.
Results in both regards similar to the popular polyurethane upper a arm bushings.
Difference between this and poly upper a arm bushings: they are very "tight" and it takes effort to move the a-arm up and down after installation. The bushings on ours are smoother (and greasable) and allows the upper a arm to locate with less force. And you get a new ball joint.
I'll shut up now and let folks with poly bushings or our steel upper a arms answer.
#20
Instructor
#21
Addict
Rennlist Member
Rennlist Member
Join Date: Feb 2004
Location: Monterey Peninsula, CA
Posts: 2,374
Likes: 0
Received 16 Likes
on
12 Posts
There should be no decrease in ride quality - the rubber bushings on the ends of the a arm do not effect smothness of the ride, but were put there to further isolate road vibrations from the chassis.
You will be able to set the camber where you want it - and it will stay put inspite of loading on the upper a arm because the rubber bushings have been eliminated. So turn-ins are more immediate and accurate, because there is no rubber bushing that must be compressed before the load can start to transfer.
Results in both regards similar to the popular polyurethane upper a arm bushings.
Difference between this and poly upper a arm bushings: they are very "tight" and it takes effort to move the a-arm up and down after installation. The bushings on ours are smoother (and greasable) and allows the upper a arm to locate with less force. And you get a new ball joint.
I'll shut up now and let folks with poly bushings or our steel upper a arms answer.
You will be able to set the camber where you want it - and it will stay put inspite of loading on the upper a arm because the rubber bushings have been eliminated. So turn-ins are more immediate and accurate, because there is no rubber bushing that must be compressed before the load can start to transfer.
Results in both regards similar to the popular polyurethane upper a arm bushings.
Difference between this and poly upper a arm bushings: they are very "tight" and it takes effort to move the a-arm up and down after installation. The bushings on ours are smoother (and greasable) and allows the upper a arm to locate with less force. And you get a new ball joint.
I'll shut up now and let folks with poly bushings or our steel upper a arms answer.
Is there a changein the kingpin angle of your new upper arm, and if so what is it compared to the old angle, and what is the measurement of the old angle.?
Thanks,
#22
Developer
Thread Starter
Richard,
The angle of the spindle is measured in degrees of inclination called Camber, and yes, our upper a-arm will accurately mimic the same camber angle as the stock one.
The angle of the spindle is measured in degrees of inclination called Camber, and yes, our upper a-arm will accurately mimic the same camber angle as the stock one.
#23
Addict
Rennlist Member
Rennlist Member
Join Date: Feb 2004
Location: Monterey Peninsula, CA
Posts: 2,374
Likes: 0
Received 16 Likes
on
12 Posts
Thanks for the response. However, this is not the question I asked. I am very much aware of Camber, and what adjustments to the angle of Camber have on the car. I asked another specific question, which is entirely different from Camber.. I asked for "kingpin angle"
Maybe you don't know what measurement I am referring to. If you don't, no problem, not many do, and even less understand it and it's effect on the car's suspension.
Thanks again,
#24
The 86.5 and later arms have an angled ball joint whereas the early arms do not. The important thing is that the ball joint doesn't reach the end the travel and overly load the joint and potentially fail the joint. I have seen someone try to fit S4 arms to early stub axles and thought it really dangerous after I saw it at full extension. That might just be because of the type of joint used by porsche and other joints may not be so limited in range, regardless something to be checked when making suspension changes.
Greg
Greg
#25
Rennlist Member
Join Date: Oct 2003
Location: toronto
Posts: 230
Likes: 0
Received 0 Likes
on
0 Posts
Has anyone used these yet, any feedback?
Replacing the arm makes sense to me. If I replace the bushings, I'm still left with a 20 yr old Ball joint.
Replacing the arm makes sense to me. If I replace the bushings, I'm still left with a 20 yr old Ball joint.
Last edited by steaditim; 07-15-2010 at 11:28 PM.
#27
Developer
Thread Starter
I will be coming out soon with a "competition" set of these a-arms, where the camber will be increased about 1.5 degrees from stock. This will make getting the camber you want in a race setup much easier.
#28
Nordschleife Master
Carl,
Richards question about the kingpin angle is a valid one.
But what he is asking is if the upper ball joint is at the exact same angle as the factory. Or if you have changed this angle. Again this is the angle of the upper ball joint to the a-arm bars
Richards question about the kingpin angle is a valid one.
But what he is asking is if the upper ball joint is at the exact same angle as the factory. Or if you have changed this angle. Again this is the angle of the upper ball joint to the a-arm bars
#29
Race Car
Any plans for lower control arms? I saw Mike Simard's ones (which look great).
Man-it's amazing for less than the price of 1 new control arm (Porsche OEM) you can get a new set of upper A arms from Carl and lower control Arms from Mike! It's a great time to own a 928!
Man-it's amazing for less than the price of 1 new control arm (Porsche OEM) you can get a new set of upper A arms from Carl and lower control Arms from Mike! It's a great time to own a 928!