Strut Tower Brace Design Revisited
Bernie Benz
b.benz at charter.net
Mon Feb 28 23:15:56 EST 2005
Scott and Peter,
You of course have free choice to embrace my strut brace design or not. If
not and you wish to actively speek out, you should have a constructive
alternative that you can technically justify or, as you have done, show a
preference for pot shot negatives in support of a do nothing posture. My
design and its justification has been offered for free use to the list, and
I am willing to further discuss reasonable quiries of same, on or off list.
George S. has implemented my design incorporating his (IMO ill conceived)
"enhancements", and has acheived the intended improvement of my design, thus
I am pleased that he apparently is a happy camper. My only point in
continueing this thread was to point out to other perspective followers that
his design enhancements were unnecessary and contribute nothing to the
intended and achieved strut brace performance.
Insert humor here:
I have discovered that when we upset our significant
others, they nag us. If we upset them even more, we
get the silent treatment. Personally, I think it's worth
the extra effort.
Bernie
From: SuffolkD at aol.com
Bernie:
Strange you'd snip someone copying your "design", comedy or not.
"Stick to your CEOing, George."
While it may keep the strut inserts aligned when the bearings or other
components are worn, there's deflection/twist in the chassis that your brace
doesn't account for.
As Peter says, your test conditions are far smoother than ours, and unless
you drive by Braille ON the lane markers on the I-5, you'd never see the
chassis flex which may show the potential short comings of the EMT in your
design, or the design itself.
I also seem to remember an engineer who also chimed in on the list a year or
two ago telling how dangerous he thought your design was.
Personally, I feel there is a reason the factory went with a tower brace
(specifically) as Bernie you corrected me on my generalization of "strut
brace."
The twist of the chassis from pot holes, understeer/oversteer while in
motion, elevation changes in mid turn, steep bisecting parking garage exit
ramps (while turning) like in California, curbs and the like.
This is easily duplicated by jacking the car up at a jack point then trying
to open the door. Chassis flex on an inferior design is evident when you
try to open the door.
This twisting of the frame is not addressed by your brace, but by every
other suspension component (in line between your brace and the applied
twisting force) until the last bit of strut movement which your brace
bridges.
Maybe IMHO that's why you haven't seen a failure in compression/tension of
the EMT. Its the bushings, strut bearing and other components that have
sacrificed themselves ahead of your EMT. Either that or the sidewall of the
tire is weaker that the EMT.
IF I was to use your "intriguing" strut brace idea I'd go the George route,
SOLID bar. but I'd also go "tower" brace ala Audi.
If there was a design flaw in the VAG tower brace (next to cost) I'm sure
they'd quickly adopt your brace idea as a cost cutting measure. The
accountants would push for it.
-Scott by BOSTON
From: Peter Schulz <>
Sorry, but your design is engineered no more or less than Georges....
Bottom line is that we all have our opinions - in the absence of the real
science of suspension design with force measurements and analysis
"If your rational were true, my strut brace designed for compression forces
only, would have hammered itself to pieces by now, under your osculating
tensile forces. Rather, it shows no sign of the tubing ever leaving the
jam nuts, the design intent."
What does that mean in respect to the road environment where you live? If
your roads are relatively smooth, you would likely see alot less strain
then on uneven, poorly maintained roads.
-Peter
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