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9 series strut mounts redrilling for -1* camber 2011-2021 bump

Quick question about this process:

You only have to move the front stud toward the inside (toward the engine bay), correct? Seems that this would affect the toe more than the camber, I would think you would want to move both the front and rear stud mounts in parallel?

Tim
 
Of course, toe must be readjusted. From my experience, that is step 3, after you set camber (1st) then caster (2nd). This modification does not permit much camber change, as the slots in the strut towers are fore & aft.....i.e. caster.
 
There was another thread on this recently; that one referred to another older one in which Janspeed did a nice writeup on moving both bolts. I don't have the links handy.
It seems to me that the difference between the two is that, in the two bolt method the maximum that the tophat can be moved Without grinding the hole in the top of the tower, is approx 10mm, and that moves the centerline of the strut assy also 10mm.
The one bolt method as above here moves the front bolt only, up to 23mm, and pivots off the stationary rear bolt. So how much the centerline moves (which would be the actual determinant of <b> camber</b> change) has not been measured AFAIK, but could be calculated if one was more up on geometry than I am currently. My guess though is that it's in the 8-11mm range. Still worthwhile.

From above diagrams
<i>They say moving the hole 3mm(0,3cm) into the longhole should be 0,25?</i>
From this, then it could be plotted what amount of movement will provide what optimal camber change. More neg camber will reduce outside edge tire wear, and increase tire bite in turns, but how much will increase inside edge wear...? And a factor for these figures would be use of car; DD, rally, etc.

Some time ago I read where some make a slot in the front hole of the tower instead of drilling new holes, so they could slide the strut assy similar to the 240's.

Natural244 said:
Quick question about this process:
You only have to move the front stud toward the inside (toward the engine bay), correct? Seems that this would affect the toe more than the camber, I would think you would want to move both the front and rear stud mounts in parallel?
Tim
Click to expand...
Moving the top of the strut assy will mostly affect camber, side to side. If fore/aft, caster. Toe would be affected only slightly if at all, and as Det17 said would be checked/adjusted last.
 
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DET17 said:
Of course, toe must be readjusted. From my experience, that is step 3, after you set camber (1st) then caster (2nd). This modification does not permit much camber change, as the slots in the strut towers are fore & aft.....i.e. caster.
Click to expand...

I've found ~1/16"/1.5mm toe OUT is optimum after this modification.
Use washers on the strut rod for caster.
 
From the green book images, is the 5083 tool merely to press out the studs? Or does it also allow you to mark the new hole location? I googled the 5083 tool and all I could find was:

Control Arm tool, to remove & install Rear control arm bushing, # 5082, # 5083, # 1801

Just curious.

Also the Janspeed thread is here http://forums.turbobricks.com/showthread.php?t=137908&highlight=strut+rotation

Tim
 
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jerryc said:
It seems to me that the difference between the two is that, in the two bolt method the maximum that the tophat can be moved Without grinding the hole in the top of the tower, is approx 10mm, and that moves the centerline of the strut assy also 10mm.
The one bolt method as above here moves the front bolt only, up to 23mm, and pivots off the stationary rear bolt. So how much the centerline moves (which would be the actual determinant of caster change) has not been measured AFAIK, but could be calculated if one was more up on geometry than I am currently. My guess though is that it's in the 8-11mm range. Still worthwhile. .
Click to expand...

I did infact pop both studs out of one tophat. From my trained eyeball, when moving exactly toward the engine CL, I could only get 9~10mm from BOTH studs (you can still see the edge of the original hole when contact with the tower is made). Considering the negative aspect of a hole directly adjacent to a hole (weaker) I proceeded with the single stud method. While the parallel stud offset would/should maintain the caster, you get the camber gain but still only net the 9~10 at the strut top mount center. With the single bolt method, the tophat is rotated, so geometrically you should gain a bit of caster as well when the strut pivots. Just scaling the tophat, I'd estimate that you are right on in your 8~11 estimate for actual movement at the top mount center.

It's clear to me why Janspeed had to cut the tower ID to get his 16mm move of the parallel studs. If my alignment shows I have not reached -1* camber, then I'll probably take his approach and cut some tower metal away, but I'd consider then to weld in some reinforcement. The ID metal (inner diameter strut tower sheet metal) adds considerable strength in compression (strut compression) but negligible strength in bending (think tower brace connection).

I'm going to shoot for 1mm of toe IN on the first alignment, but I do know muscle car guys running approx. 1mm toe OUT without getting the car too skittish, squirrelly.
 
Did volvo ever make 'crash mounts' for these car (factory camber-correction mounts)? Or was the drill and move method the only factory-approved camber correction method?
 
And I misspoke in my analysis; This
<i> So how much the centerline moves (which would be the actual determinant of caster change)</i>
should be This
So how much the centerline moves (which would be the actual determinant of <b>camber</b> change)
I'll edit that post so it's not confusing.
 
jerryc said:
And I misspoke in my analysis; This
<i> So how much the centerline moves (which would be the actual determinant of caster change)</i>
should be This
So how much the centerline moves (which would be the actual determinant of <b>camber</b> change)
I'll edit that post so it's not confusing.
Click to expand...

Yer thinkin' is severely impacting yer doin'.
 
peehound said:
Yer thinkin' is severely impacting yer doin'.
Click to expand...

Aw shucks...
:neener:

I have very limited time to put into my cars. I try to plan ahead, and not have to say 'dang, I wish I'd thought of that before'

'measure twice, cut once' 'twas said.
Or, 'Make careful decisions and then pull the trigger'

Occasionally I do it that way. :cool:
 
It's not THAT important that you do 100% same movement on both left and right bearing since it's probably not known if the camber left and right are symmetrical before this mod. (often they differ a little on these old cars). If wanting to get "serious" go make a alignment before and check the camber, then move the upper mounts accordingly to get symmetry.


Actually it is better to move rear bolt since the lever effect is better on that one, the lever is about 0.6 vs 0.4 on the front bolt. Which means you gain more neg camber by moving the rear bolt.
 
JE Jr said:
Actually it is better to move rear bolt since the lever effect is better on that one, the lever is about 0.6 vs 0.4 on the front bolt. Which means you gain more neg camber by moving the rear bolt.
Click to expand...

Ratio wise, correct, but caster wise, directionally incorrect! Pivoting from the front would most certainly lose caster, but as you note will gain you more camber. Perhaps a hybrid modification of the rear bolt and using the Janspeed "shims" trick at the stay rod.

To your first point on "as found" data, correct. Measure twice, cut once......and if you want REAL precision stack the drivers seat with your equivalent body weight to load suspension before you measure. I've seen it done already.
 
I'm fully aware of that, but the caster you will lose by moving the inner bolt ~15-25mm is negligble, maybe 0.1degrees maximum.

What can be more benefitical is that you will probably gain more negative camber before the tophat hits the strut tower (if you cut out some material on the upper side).
 
JE Jr said:
It's not THAT important that you do 100% same movement on both left and right bearing ...
Click to expand...
True no doubt, especially for a DD/keep it running ok sort of thing, but for me it's also a hobby so it's fun, and one thing I can control fairly easily and cheaply. Some do race these, and maybe our little exercise in going through it will spark some tiny bit of performance gain.

I once had a 72 Camaro and on a trip from Boston to Miami felt the car was pulling. I stopped by a small town alignment shop in South Carolina and they put it on the rack and this wizened old codger did his stuff.
That car to this day was the straightest driving car I have ever been in. On some straight parts of 95 I could take my hands off the wheel for a mile, no lie.
 
JE Jr said:
I'm fully aware of that, but the caster you will lose by moving the inner bolt ~15-25mm is negligble, maybe 0.1degrees maximum.

What can be more benefitical is that you will probably gain more negative camber before the tophat hits the strut tower (if you cut out some material on the upper side).
Click to expand...

Would be interested to offset one each front, rear, and install & measure both. I'm not buying the 0.1* of caster reduction, but only measurement would tell the truth. If someone were REALLY bored (maybe retired) they could modify one each way, take before and after camber & caster measurements so we would all know. I don't have that much time.....;-)
 
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