Strut Tower Brace
07-10-2008, 12:44 PM
#4
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They do have a few notable benefits:
- they add weight to the front end of the car (which is already too heavy)
- they add weight at the top of the engine bay, which will hurt handling
- they make it tough to do routine maintenance
- they take hard-earned cash away from mods that actually help
I'm being sarcastic, of course - but my point is valid. They really do nothing to help rigidity. The brace is there to prevent the shock towers from leaning in toward each other. That's it's only function.
The problem with this is that there are no forces in our suspension that would force the towers inward! When you put lateral loads on the car, those forces are transferred through the A-arms and into the frame. These arms are not mounted to the towers.
The only thing that's mounted to the towers are the shock/spring combo. Now, it's true that the shock tower is effectively supporting the weight of the front of the car. However, the springs are almost completely vertical. Therefore, the loads placed on the towers are also vertical. And, the brace will do nothing to lessen vertical loads.
In short, don't waste the money.
- they add weight to the front end of the car (which is already too heavy)
- they add weight at the top of the engine bay, which will hurt handling
- they make it tough to do routine maintenance
- they take hard-earned cash away from mods that actually help
I'm being sarcastic, of course - but my point is valid. They really do nothing to help rigidity. The brace is there to prevent the shock towers from leaning in toward each other. That's it's only function.
The problem with this is that there are no forces in our suspension that would force the towers inward! When you put lateral loads on the car, those forces are transferred through the A-arms and into the frame. These arms are not mounted to the towers.
The only thing that's mounted to the towers are the shock/spring combo. Now, it's true that the shock tower is effectively supporting the weight of the front of the car. However, the springs are almost completely vertical. Therefore, the loads placed on the towers are also vertical. And, the brace will do nothing to lessen vertical loads.
In short, don't waste the money.
07-10-2008, 01:22 PM
#6
.......The problem with this is that there are no forces in our suspension that would force the towers inward! When you put lateral loads on the car, those forces are transferred through the A-arms and into the frame. These arms are not mounted to the towers.
The only thing that's mounted to the towers are the shock/spring combo. Now, it's true that the shock tower is effectively supporting the weight of the front of the car. However, the springs are almost completely vertical. Therefore, the loads placed on the towers are also vertical. And, the brace will do nothing to lessen vertical loads.
In short, don't waste the money.
The only thing that's mounted to the towers are the shock/spring combo. Now, it's true that the shock tower is effectively supporting the weight of the front of the car. However, the springs are almost completely vertical. Therefore, the loads placed on the towers are also vertical. And, the brace will do nothing to lessen vertical loads.
In short, don't waste the money.
Sure about that? I do believe that the bolts that connect the upper shock mount to the shock tower are the same bolts that also pass through the upper a-arm mounting bracket....AND, the same bolts that the STB connects to.
07-10-2008, 03:46 PM
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They do have a few notable benefits:
- they add weight to the front end of the car (which is already too heavy)
- they add weight at the top of the engine bay, which will hurt handling
- they make it tough to do routine maintenance
- they take hard-earned cash away from mods that actually help
I'm being sarcastic, of course - but my point is valid. They really do nothing to help rigidity. The brace is there to prevent the shock towers from leaning in toward each other. That's it's only function.
The problem with this is that there are no forces in our suspension that would force the towers inward! When you put lateral loads on the car, those forces are transferred through the A-arms and into the frame. These arms are not mounted to the towers.
The only thing that's mounted to the towers are the shock/spring combo. Now, it's true that the shock tower is effectively supporting the weight of the front of the car. However, the springs are almost completely vertical. Therefore, the loads placed on the towers are also vertical. And, the brace will do nothing to lessen vertical loads.
In short, don't waste the money.
- they add weight to the front end of the car (which is already too heavy)
- they add weight at the top of the engine bay, which will hurt handling
- they make it tough to do routine maintenance
- they take hard-earned cash away from mods that actually help
I'm being sarcastic, of course - but my point is valid. They really do nothing to help rigidity. The brace is there to prevent the shock towers from leaning in toward each other. That's it's only function.
The problem with this is that there are no forces in our suspension that would force the towers inward! When you put lateral loads on the car, those forces are transferred through the A-arms and into the frame. These arms are not mounted to the towers.
The only thing that's mounted to the towers are the shock/spring combo. Now, it's true that the shock tower is effectively supporting the weight of the front of the car. However, the springs are almost completely vertical. Therefore, the loads placed on the towers are also vertical. And, the brace will do nothing to lessen vertical loads.
In short, don't waste the money.
Am I on the right track toward figuring out why the 3rd gen strut suspension has an effect if you add a STB?
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07-10-2008, 03:48 PM
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If the lateral force is only applied through the lower A-arm... question is does any force get applied against the spindle arm which is really the only thing connecting it to the upper a-arm
07-10-2008, 05:19 PM
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Now you have me drawing on paper trying to figure this out. Lateral forces are transferred through the K member right? Is any lateral force applied to the upper a-arms? I can't picture it, but it just seems like the only force being applied to that part is up and down.
Am I on the right track toward figuring out why the 3rd gen strut suspension has an effect if you add a STB?
Am I on the right track toward figuring out why the 3rd gen strut suspension has an effect if you add a STB?
07-10-2008, 05:47 PM
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Convertibles show some cowl shake when you throw
them around corners and the brace eliminates that.
Think of it more as a shake "snubber" than anything
structurally stout. It will change the "feel", whether
or not it does anything quantifiable is an old and
persistent question.
However the 3-point has anecdotes of breaking
windshields as it it transferring force to a weak
patch of plain sheet metal. So that says (a) don't
go that way and (b) some kind of flex is being
pushed down the brace. Though 1/8" - 1/4" is all
it takes to crack glass and maybe not enough to
be worth trying to eliminate.
Still on a floppy car it improves an annoying thing.
Did for me anyway. Buy used.
them around corners and the brace eliminates that.
Think of it more as a shake "snubber" than anything
structurally stout. It will change the "feel", whether
or not it does anything quantifiable is an old and
persistent question.
However the 3-point has anecdotes of breaking
windshields as it it transferring force to a weak
patch of plain sheet metal. So that says (a) don't
go that way and (b) some kind of flex is being
pushed down the brace. Though 1/8" - 1/4" is all
it takes to crack glass and maybe not enough to
be worth trying to eliminate.
Still on a floppy car it improves an annoying thing.
Did for me anyway. Buy used.
07-10-2008, 06:08 PM
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right on well guys thanks for the input. I was just wondering if the strut tower brace was worth it, and clearly its not.
But this weekend I will be slapping on some UMI pieces to the WS6
But this weekend I will be slapping on some UMI pieces to the WS6
07-10-2008, 09:40 PM
#15
Launching!
As has been said, most of the force goes through the lower control arm on a 4th gen front end. What's left simply isn't enough to cause significant deflection of the shock towers.
07-10-2008, 10:17 PM
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i got the edelbrock 3 point and it did seem to make the front end track better. and overall a slightly tighter feel over road imperfections. i bought mine NIB used. no cracks in the glass as of yet......
07-10-2008, 11:01 PM
#17
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On a 4th gen F-car a STB doesn't really do much, except for maybe if your shocks are worn out or the structural integrity has been compromised by a wreck. The double A-arm setup used in our cars actually directs most of the shock through the k-member rather than into the towers like a true McPherson setup would (like in a 3rd gen). Even in auto X circles its generally just considered to be an appearance mod for a 4th gen.
07-11-2008, 02:45 AM
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There have been several instances where engineery type people have instrumented their cars with strain gauges and found that almost no load passes through a 4th gen shock tower brace.
As has been said, most of the force goes through the lower control arm on a 4th gen front end. What's left simply isn't enough to cause significant deflection of the shock towers.
As has been said, most of the force goes through the lower control arm on a 4th gen front end. What's left simply isn't enough to cause significant deflection of the shock towers.
what did they use to measure the stress a strain gauge? or did they do a finite element model?
sorry for the techno babble I am a mechanical engineer and you just really peaked my interest
07-11-2008, 02:55 AM
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Really, if done thoroughly, both an accurate FEM and strain gauge prototyping (some sort of wheatstone bridge circuit would best with the flat surfaces) would be a few things to start with. Correct me on this, but that's what I remember, though my coursework major (ChemEng with a MatSci emphasis) dealt with mostly grain structures.
Last edited by Foxxtron; 07-11-2008 at 03:07 AM.
07-11-2008, 03:21 AM
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And BTW, I hope more people like you can question these mods like myself, because I've seen significant amounts of "ball-dropping" in both the OE and aftermarket.
Now, I have a general enquiry for the whole forum that I've brought up once or numerously in the past:
Why are almost all of the STB's available for the 4th-Gen F-body have really small plates that are only fastened by the front two bolts of the shock tower, as opposed to a design that fastens to all four? Is there only a small but very significant load placed just in that little area?