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Lowering ball joints by Knight
Started on: 02-12-2014 05:33 PM
Replies: 9 (968 views)
Last post by: weloveour86se on 11-11-2014 08:44 AM
Knight
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Report this Post02-12-2014 05:33 PM Click Here to See the Profile for KnightSend a Private Message to KnightEdit/Delete MessageReply w/QuoteDirect Link to This Post
Was thinking about getting Rodney Dickman 1" lowering ball joint. Since the upper a-arm is now angled up as it goes to the spindle, how will that effect roll center and therefor handling. I mean besides the greater camber gain with suspension travel. I can't remember all the rol center vs center of gravity vs ect
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Report this Post02-12-2014 06:54 PM Click Here to See the Profile for fieroguruSend a Private Message to fieroguruEdit/Delete MessageReply w/QuoteDirect Link to This Post
At stock ride height the 88 front suspension is pretty decent and the roll center only moves vertically about 19mm through 6 degrees of roll. So the imaginary lever arm between the RC and the CG remains pretty constant through the roll.

Lower it 1 1/2" (the amount I have data for) with springs or lowering ball joints and the roll center is lowered as well. But now the RC moves nearly 88mm vertically through the same 6 degrees of roll. So as the car rolls, the lever arm between the RC and the CG becomes increasing longer and increases the tendency for it roll further.

Most people lower it for looks and the less favorable geometry isn't really noticeable on a street car. However, start pushing it in the corners and you will likely find that you need to increase the front spring rate to help keep roll in check
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Knight
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Report this Post02-19-2014 08:56 PM Click Here to See the Profile for KnightSend a Private Message to KnightEdit/Delete MessageReply w/QuoteDirect Link to This Post
I have a 86 SE and handling is more important than looks. So I am hesitating on buying the 1 inch lowering ball joints until I know if it will harm handling.
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Knight
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Report this Post02-20-2014 09:16 PM Click Here to See the Profile for KnightSend a Private Message to KnightEdit/Delete MessageReply w/QuoteDirect Link to This Post
Anybody have any feedback as it relates to the 84-87? Besides, the effect to roll center is different between a lowering spring ( both arms are equally changed within original geometry) and using a lowering ball joint (changes the suspension geometry because it changes the relationship between the two arms).
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gwg1995
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Report this Post03-01-2014 08:03 PM Click Here to See the Profile for gwg1995Click Here to Email gwg1995Send a Private Message to gwg1995Edit/Delete MessageReply w/QuoteDirect Link to This Post
From what I have read, it doesn't affect suspension geometry. Look at Rodney's diagrams on his website.

http://rodneydickman.com/ca...6_44&products_id=207

I just ordered the 1" lowering ball joints, adjustable upper ball joints, and zero-lash sway bar links.
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Report this Post03-01-2014 09:00 PM Click Here to See the Profile for fieroguruSend a Private Message to fieroguruEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by gwg1995:

From what I have read, it doesn't affect suspension geometry. Look at Rodney's diagrams on his website.

http://rodneydickman.com/ca...6_44&products_id=207

I just ordered the 1" lowering ball joints, adjustable upper ball joints, and zero-lash sway bar links.


It does. Rodney's sketches show the angle of the a-arms, but suspension geometry is dictated by the locations of the pivots (bushings and balljoints).

Even with the lowering ball joints, the pivots of the ball joints remain the same as stock. But the car/chassis is lowered, so the inboard pivots of the bushings (both upper and lower) are lowered and that changes the geometry.

The only way to lower the car without significantly changing the geometry is to lower the ball joint pivots (upper and lower) the same as the chassis (bushing locations) is lowered. This is done with dropped spindles.
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Knight
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Report this Post11-10-2014 07:53 PM Click Here to See the Profile for KnightSend a Private Message to KnightEdit/Delete MessageReply w/QuoteDirect Link to This Post
So does lowering with drop spindles effect the RC to CG lever arm? And if it does, is it a negative enough change to off set the advantage of lowering the cars CG?
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weloveour86se
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Report this Post11-11-2014 08:05 AM Click Here to See the Profile for weloveour86seSend a Private Message to weloveour86seEdit/Delete MessageReply w/QuoteDirect Link to This Post
Rodney actually chimes in on this thread.
http://www.fiero.nl/forum/Forum2/HTML/124865.html

How is an "adjustable" ball joint adjustable when you are required to grind the hole out. Wouldn't a "regular" non adjustable ball joint be the same? So grinding the UCA ball joint hole out and making it larger makes the ball joint "adjustable"?
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Report this Post11-11-2014 08:32 AM Click Here to See the Profile for fierosoundClick Here to visit fierosound's HomePageClick Here to Email fierosoundSend a Private Message to fierosoundEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by weloveour86se:

Rodney actually chimes in on this thread.
http://www.fiero.nl/forum/Forum2/HTML/124865.html

How is an "adjustable" ball joint adjustable when you are required to grind the hole out. Wouldn't a "regular" non adjustable ball joint be the same? So grinding the UCA ball joint hole out and making it larger makes the ball joint "adjustable"?


Have you seen and compared the stock and the slotted mount ball joints?
You need ball joints with the slotted mounts to get any adjustment at all.
Sometimes the control arm hole limits how far the ball joint can move in the slots.

With the regular ball joint, you'd need to slot the ball joint mounting holes IN the control arm
AND the large hole the ball joint goes through to get the same degree of adjustment.

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weloveour86se
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Report this Post11-11-2014 08:44 AM Click Here to See the Profile for weloveour86seSend a Private Message to weloveour86seEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by fierosound:


Have you seen and compared the stock and the slotted mount ball joints?
You need ball joints with the slotted mounts to get any adjustment at all.
Sometimes the control arm hole limits how far the ball joint can move in the slots.

With the regular ball joint, you'd need to slot the ball joint mounting holes IN the control arm
AND the large hole the ball joint goes through to get the same degree of adjustment.


Yes I have. Check the thread I linked for some pics and scribbles on said pics. The base of RD's adjustable ball joint, the actual part where the ball sits in is wider then a regular non adjustable ball joint. This base fills the hole in the UCA and prevents adjustments. This is what necessitates grinding. Check the linked thread.

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