Suspension
10-15-2006, 08:54 PM
#13
5th Gear Member
Join Date: May 2005
Location:
Posts: 2,445
RE: Suspension
ORIGINAL: fastback311
whats the easiest way to lower the front end of a 69 fastback while keeping stock parts i want to lower it about 2 inches
whats the easiest way to lower the front end of a 69 fastback while keeping stock parts i want to lower it about 2 inches
Hey man, you asked for the easiest way
Good luck,
10-16-2006, 08:30 PM
#17
1st Gear Member
Join Date: Apr 2006
Location: San Diego, CA
Posts: 126
RE: Suspension
I have followed several of the threads on suspension, including the shelby drop. And I have a few questions that seem to be related to this thread about what to keep stock and what to replace.
#1 I can understand how the spings compressing up and down could fatigue them. But what about UCA and LCAs. since they are mostly pivoting up and down do they also fatigue? Is there a problem or and danger with using new springs on existing UCA and LCA after cleaning them up replacing the bushings and possibly new ball joints? Do they need to be replaced after 40 years due to fatigue. I could also understnd that upgraded UCA and LCA can change the geometry and therefore the performance but Is there any benefit to putting in a new version of the same stock UCA and LCA?
#2 I can see how sway bars are subject to torque, do they also fatigue and need to be replaced? Or is it mostly upgrading to new bushings and or increasing the thickness of the bar.
#3 Finally this may be a dumb question but here goes. When you do the shelby drop you are lowering the holes where the UCR attaches to the body, doesn't that mean that the body is now higher up in relation to the UCR. To me is seems like if Im holding a file box from holes near the top of the box then I move my hands to the bottom of the box the box now sits higher up. I'm probably missing some other effect on the geometry from the LCR or Struts but it seems that moving the UCR lower on the car frame raise the car?
#1 I can understand how the spings compressing up and down could fatigue them. But what about UCA and LCAs. since they are mostly pivoting up and down do they also fatigue? Is there a problem or and danger with using new springs on existing UCA and LCA after cleaning them up replacing the bushings and possibly new ball joints? Do they need to be replaced after 40 years due to fatigue. I could also understnd that upgraded UCA and LCA can change the geometry and therefore the performance but Is there any benefit to putting in a new version of the same stock UCA and LCA?
#2 I can see how sway bars are subject to torque, do they also fatigue and need to be replaced? Or is it mostly upgrading to new bushings and or increasing the thickness of the bar.
#3 Finally this may be a dumb question but here goes. When you do the shelby drop you are lowering the holes where the UCR attaches to the body, doesn't that mean that the body is now higher up in relation to the UCR. To me is seems like if Im holding a file box from holes near the top of the box then I move my hands to the bottom of the box the box now sits higher up. I'm probably missing some other effect on the geometry from the LCR or Struts but it seems that moving the UCR lower on the car frame raise the car?
10-16-2006, 10:12 PM
#18
5th Gear Member
Join Date: May 2005
Location:
Posts: 2,445
RE: Suspension
ORIGINAL: fastback311
how would i securely mount the fat chicks ya know so i got a smooth ride
how would i securely mount the fat chicks ya know so i got a smooth ride
Again, this is the easy way. Definitely not the best or smartest, or even the longest lasting.
10-16-2006, 10:31 PM
#19
5th Gear Member
Join Date: May 2005
Location:
Posts: 2,445
RE: Suspension
ORIGINAL: DrBob67
I have followed several of the threads on suspension, including the shelby drop. And I have a few questions that seem to be related to this thread about what to keep stock and what to replace.
#1 I can understand how the spings compressing up and down could fatigue them. But what about UCA and LCAs. since they are mostly pivoting up and down do they also fatigue? Is there a problem or and danger with using new springs on existing UCA and LCA after cleaning them up replacing the bushings and possibly new ball joints? Do they need to be replaced after 40 years due to fatigue. I could also understnd that upgraded UCA and LCA can change the geometry and therefore the performance but Is there any benefit to putting in a new version of the same stock UCA and LCA?
#2 I can see how sway bars are subject to torque, do they also fatigue and need to be replaced? Or is it mostly upgrading to new bushings and or increasing the thickness of the bar.
#3 Finally this may be a dumb question but here goes. When you do the shelby drop you are lowering the holes where the UCR attaches to the body, doesn't that mean that the body is now higher up in relation to the UCR. To me is seems like if Im holding a file box from holes near the top of the box then I move my hands to the bottom of the box the box now sits higher up. I'm probably missing some other effect on the geometry from the LCR or Struts but it seems that moving the UCR lower on the car frame raise the car?
I have followed several of the threads on suspension, including the shelby drop. And I have a few questions that seem to be related to this thread about what to keep stock and what to replace.
#1 I can understand how the spings compressing up and down could fatigue them. But what about UCA and LCAs. since they are mostly pivoting up and down do they also fatigue? Is there a problem or and danger with using new springs on existing UCA and LCA after cleaning them up replacing the bushings and possibly new ball joints? Do they need to be replaced after 40 years due to fatigue. I could also understnd that upgraded UCA and LCA can change the geometry and therefore the performance but Is there any benefit to putting in a new version of the same stock UCA and LCA?
#2 I can see how sway bars are subject to torque, do they also fatigue and need to be replaced? Or is it mostly upgrading to new bushings and or increasing the thickness of the bar.
#3 Finally this may be a dumb question but here goes. When you do the shelby drop you are lowering the holes where the UCR attaches to the body, doesn't that mean that the body is now higher up in relation to the UCR. To me is seems like if Im holding a file box from holes near the top of the box then I move my hands to the bottom of the box the box now sits higher up. I'm probably missing some other effect on the geometry from the LCR or Struts but it seems that moving the UCR lower on the car frame raise the car?
1). The control arm themselves, probably not. The bushing should definitely be replaced, and the ball joints inspected for wear. If they aren't loose, chances are good they do not need replacement.
If you decide to start driving the car more aggressively than it was originally intended to be driven, then upgrading would be a smart idea. Not simply replacing stock piece for stock piece, but upgrading to a boxed style or tube style control arm. The original equipment control arms were very stout. Most of the crap coming out of Asia is not near the quality. Driving more aggressively includes, installing radial tires with more grip, allowing not just higher cornering forces, but especially more braking force to act upon the control arms.
2). Mostly upgrading the thickness and bushings. If your car was tracked every weekend, you may see a reduction is resistance to twisting force. Otherwise, it's just to improve the suspension for less body roll.
3). That is an astute observation. Remember the spring is what holds the body up, not the control arm. The spring itself sits on top of the control arm (via the perch). By doing the 1" drop that Klaus Arning engineered you change the relative angle of the control arm in comparison to horizontal. The outer end of the control arm points up more. And in fact the chassis sits slightly lower when referenced off the spring perch.
It is the increase in upward angle at ride height that directly affects the camber curve. Which is what this modification is all about.
Good questions. Hope this helps.
Scott
10-16-2006, 11:28 PM
#20
1st Gear Member
Join Date: Apr 2006
Location: San Diego, CA
Posts: 126
RE: Suspension
ORIGINAL: Scott H.
IMO,
1). The control arm themselves, probably not. The bushing should definitely be replaced, and the ball joints inspected for wear. If they aren't loose, chances are good they do not need replacement.
If you decide to start driving the car more aggressively than it was originally intended to be driven, then upgrading would be a smart idea. Not simply replacing stock piece for stock piece, but upgrading to a boxed style or tube style control arm. The original equipment control arms were very stout. Most of the crap coming out of Asia is not near the quality. Driving more aggressively includes, installing radial tires with more grip, allowing not just higher cornering forces, but especially more braking force to act upon the control arms.
2). Mostly upgrading the thickness and bushings. If your car was tracked every weekend, you may see a reduction is resistance to twisting force. Otherwise, it's just to improve the suspension for less body roll.
3). That is an astute observation. Remember the spring is what holds the body up, not the control arm. The spring itself sits on top of the control arm (via the perch). By doing the 1" drop that Klaus Arning engineered you change the relative angle of the control arm in comparison to horizontal. The outer end of the control arm points up more. And in fact the chassis sits slightly lower when referenced off the spring perch.
It is the increase in upward angle at ride height that directly affects the camber curve. Which is what this modification is all about.
Good questions. Hope this helps.
Scott
ORIGINAL: DrBob67
I have followed several of the threads on suspension, including the shelby drop. And I have a few questions that seem to be related to this thread about what to keep stock and what to replace.
#1 I can understand how the spings compressing up and down could fatigue them. But what about UCA and LCAs. since they are mostly pivoting up and down do they also fatigue? Is there a problem or and danger with using new springs on existing UCA and LCA after cleaning them up replacing the bushings and possibly new ball joints? Do they need to be replaced after 40 years due to fatigue. I could also understnd that upgraded UCA and LCA can change the geometry and therefore the performance but Is there any benefit to putting in a new version of the same stock UCA and LCA?
#2 I can see how sway bars are subject to torque, do they also fatigue and need to be replaced? Or is it mostly upgrading to new bushings and or increasing the thickness of the bar.
#3 Finally this may be a dumb question but here goes. When you do the shelby drop you are lowering the holes where the UCR attaches to the body, doesn't that mean that the body is now higher up in relation to the UCR. To me is seems like if Im holding a file box from holes near the top of the box then I move my hands to the bottom of the box the box now sits higher up. I'm probably missing some other effect on the geometry from the LCR or Struts but it seems that moving the UCR lower on the car frame raise the car?
I have followed several of the threads on suspension, including the shelby drop. And I have a few questions that seem to be related to this thread about what to keep stock and what to replace.
#1 I can understand how the spings compressing up and down could fatigue them. But what about UCA and LCAs. since they are mostly pivoting up and down do they also fatigue? Is there a problem or and danger with using new springs on existing UCA and LCA after cleaning them up replacing the bushings and possibly new ball joints? Do they need to be replaced after 40 years due to fatigue. I could also understnd that upgraded UCA and LCA can change the geometry and therefore the performance but Is there any benefit to putting in a new version of the same stock UCA and LCA?
#2 I can see how sway bars are subject to torque, do they also fatigue and need to be replaced? Or is it mostly upgrading to new bushings and or increasing the thickness of the bar.
#3 Finally this may be a dumb question but here goes. When you do the shelby drop you are lowering the holes where the UCR attaches to the body, doesn't that mean that the body is now higher up in relation to the UCR. To me is seems like if Im holding a file box from holes near the top of the box then I move my hands to the bottom of the box the box now sits higher up. I'm probably missing some other effect on the geometry from the LCR or Struts but it seems that moving the UCR lower on the car frame raise the car?
1). The control arm themselves, probably not. The bushing should definitely be replaced, and the ball joints inspected for wear. If they aren't loose, chances are good they do not need replacement.
If you decide to start driving the car more aggressively than it was originally intended to be driven, then upgrading would be a smart idea. Not simply replacing stock piece for stock piece, but upgrading to a boxed style or tube style control arm. The original equipment control arms were very stout. Most of the crap coming out of Asia is not near the quality. Driving more aggressively includes, installing radial tires with more grip, allowing not just higher cornering forces, but especially more braking force to act upon the control arms.
2). Mostly upgrading the thickness and bushings. If your car was tracked every weekend, you may see a reduction is resistance to twisting force. Otherwise, it's just to improve the suspension for less body roll.
3). That is an astute observation. Remember the spring is what holds the body up, not the control arm. The spring itself sits on top of the control arm (via the perch). By doing the 1" drop that Klaus Arning engineered you change the relative angle of the control arm in comparison to horizontal. The outer end of the control arm points up more. And in fact the chassis sits slightly lower when referenced off the spring perch.
It is the increase in upward angle at ride height that directly affects the camber curve. Which is what this modification is all about.
Good questions. Hope this helps.
Scott
Your reply helps to confirm what I thought. After too many tickets since I was 16, although now in my 40's I have mellowed out. Also I'm not planning on doing much aggresive driving and don't plan on going to the track soon. But I guess you never know. So I'll probably try keeping it mostly stock with replacing worn parts like bushings, do the shelby drop, and maybe take out half a spring and see how that changes things. Then if that is not enough go farther with upgraded arms. Even though that is doing things twice. But to most everyone on this forum, this is a hobby not just car repair.
#1 I have no indication that the ball joints are loose but the rubber or whatever covering around it bushing around it is shot. So I didn't think there was a way to replace only the cover. So as far as the U&LCAs go I did not see a reason to replace them with a newer version of the same just because they are old.
#2 Thicker swaybar and urethane bushings seems like a good idea.
#3 I figured that there was something I was not considering in the geometry. I was only considering the two dimensional effect of the lowered holes. As you mentioned there is a three dimensional effect, taking into account the outer end of the UCA. Thanks for the clarification.
Bob
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