Harness Strut Tower Brace
01-27-2003, 10:57 AM
#1
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Join Date: Aug 2002
Location: Denver, CO
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I know M2 makes one, but $249?? Ouch.
Anybody ever think of making their own strut tower brace/harness bar? I'm under the impression that the stock STB weak point is the threaded adjustment at the end of the bar. I am thinking, that I could just remove the stock brace, make a template, cut some steel and weld it up so there is a solid square tubular bar, no adjustability, with threaded inserts welded in. I figure it'll cost $50 for the steel and welding, and take a few days to make. Maybe get a powdercoat, too. Total cost of less than $100. Any thoughts?
Anybody ever think of making their own strut tower brace/harness bar? I'm under the impression that the stock STB weak point is the threaded adjustment at the end of the bar. I am thinking, that I could just remove the stock brace, make a template, cut some steel and weld it up so there is a solid square tubular bar, no adjustability, with threaded inserts welded in. I figure it'll cost $50 for the steel and welding, and take a few days to make. Maybe get a powdercoat, too. Total cost of less than $100. Any thoughts?
01-27-2003, 03:23 PM
#6
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Originally Posted by Sinful7' date='Jan 27 2003, 11:57 AM
.....Anybody ever think of making their own strut tower brace/harness bar? I'm under the impression that the stock STB weak point is the threaded adjustment at the end of the bar.....
the weak point m2 points out on the rear factory strut bar is marketing...
take notice your seatbelt bolts...most of which is reused as far as installation points
on most of your aftermarket harnesses....similar to that of the threaded piece in question...
friend with fd whose wrecked twice via tree and roll over on summit point with ...
stock factory seatbelt...of which has similar properties if not identical with that of the
suggested weak point of the factory rear bar...held
01-28-2003, 12:19 AM
#7
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I agree.. it's just that the "weak point" is - what seems to be - a grade 5 or equivalent fastener. The shank is a mere M8x1.5 (8mm x 1.5 thread pitch.) Maybe if I can find a grade 8 pivot ball I might be better off. All of the seat belt points are held firmly together by a LARGE grade 8 bolt.. probably 1/2" or better..
Here's the problem, as I see it, with the stock STB.
The first scenario is the seat-belt style mount. The left arrow represents force applied by the belt, the right arrow represents the equal but opposite force applied by the car body. The two surfaces are very close together, nearly on the same plane. (If they were on the same plane, it would be like trying to tear the bolt in half.. not gonna happen.)
The second scene shows the distance between the weak point attachment to the STB mount and the STB itself. As you can see, the forces are a great distance apart, which could cause the bolt to stress, bend and after fatigued, fail.
The purpose of this bar is to eliminate the "gap". It just happens that the easiest way to do that is by replacing the bar entirely, since modifications to the stud in question are impossible (at best).
Here's the problem, as I see it, with the stock STB.
The first scenario is the seat-belt style mount. The left arrow represents force applied by the belt, the right arrow represents the equal but opposite force applied by the car body. The two surfaces are very close together, nearly on the same plane. (If they were on the same plane, it would be like trying to tear the bolt in half.. not gonna happen.)
The second scene shows the distance between the weak point attachment to the STB mount and the STB itself. As you can see, the forces are a great distance apart, which could cause the bolt to stress, bend and after fatigued, fail.
The purpose of this bar is to eliminate the "gap". It just happens that the easiest way to do that is by replacing the bar entirely, since modifications to the stud in question are impossible (at best).
01-28-2003, 10:14 AM
#10
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Join Date: Aug 2002
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Well, construction is underway. I think I have a solution.. I'm re-using the stock STB's end brackets, but replacing the center section with a reinforced unit. I am using a solid 3/4" steel bar, surrounded by a 1" steel square tube, (.125" wall). It will be finished by a 1.5x.125" steel plate running the length of the bar, with a .5" reinforcement under the overhanging portion. The steel top plate and reinforcement bar will be drilled to allow the installation of harness bolts. This *should* be strong enough to mount harnesses to, and it really only has to work once.
I'll keep everyone updated!
I'll keep everyone updated!