[s-cars] Woah! pics link

[Taka Mizutani]

Relax, Eric-
I wasn't making a jab at you- if I way, I'd name you, I don't beat around
the bush.

I didn't think it was fair, what Greg A. did by banning you from BIRA.

I'm not being provocative or careless- I was merely stating my observations.
Was I being too subjective? Maybe.

I don't harbor any ill will toward ECS, BIRA or any of these companies in
question, nor do I toward you.

You're taking this way too personally.

As it stands, I too would select RS2 forged steel brackets for a BBK. Now
you have me thinking about pulling the brakes on the STi and the V70R to see
what these two OEMs did for mounting Brembo brakes.

Taka


On 7/18/07, Eric Phillips <gcmschemist at gmail.com> wrote:
>
> Taka:
>
> Debacle?!?  Reasoned arguments sprinkled with educated speculation are
> not the stuff of "debacles".
>
> You are correct that there have been no *reported* cracking issues
> with BIRA brackets.  Lack of reportage does not imply that the design
> is adequate.  Only detailed engineering analysis or test-to-failure
> can answer that question.
>
> I'm not sure if you're being provacative or careless in your word
> choices.  If you have data to put the questions to rest, I'd love to
> see them.  I will gladly eat a huge helping of cold crow if the data
> turn out to refute my position in the matter.  My only concern, from
> the very beginning, is the safe transport of my fellow UrS car
> drivers.  If the BIRA stuff can do that equally as well as the
> Porsche/Audi-designed stuff, cool.  If not, then folks looking to
> upgrade shouldn't be steered in that direction.
>
> It's really just that simple, IMO.
>
> Which is exactly why I chose RS2 brackets and A8L D2 rotors for my
> BBK.  Cheap, effective, proven.  ECS?  Avoid.  BIRA?  Unknown,
> excessive legalese, slow to get parts, and more expensive.
>
> From where I sit, it looks like a pretty clear choice.  But as in all
> matters of human endeavor...
>
> Eric
>
> > Date: Wed, 18 Jul 2007 10:44:16 -0400
> > From: "Taka Mizutani" <t44tqtro at gmail.com>
> > Subject: Re: [s-cars] Woah! pics link
> >
> > I do recall something about the improvements that ECS made to their
> brackets
> > after the whole cracking thing came to light several months ago.
> >
> > I do know that ECS will replace existing brackets at no cost to the
> > customer, other than shipping, IIRC.
> >
> > After the whole ECS debacle, there was another debacle about BIRA and
> debate
> > whether or not BIRA's brackets may do the same thing, but I don't think
> any
> > cracking reports have occurred with the BIRA brackets.
> >
> > I thought the ECS brackets placed the caliper in the same orientation as
> the
> > RS2 brackets. If that's not the case, then using RS2 brackets would
> > necessitate a custom hat or the use of A8L one-piece rotors. At least
> the
> > RS2 brackets are forged steel, so the chance of stress cracking is much
> > lower.
> >
> > Taka
> >
> >
> > On 7/18/07, Paul Gailus <gailus at mindspring.com> wrote:
> > >
> > > While I'm not a metallurgist, I have a suspicion that this failure
> > > could've been caused by stress corrosion cracking and/or fatigue
> cracking
> > > along the grain of the aluminum alloy. Hot-rolled plate stock will
> tend
> > > to have some unrecrystallized grain structure in layers that can act
> as
> > > slip planes in a fracture.
> > > For example, see the discussion at:
> > > http://www.key-to-metals.com/Article114.htm
> > >
> > > Being in the "salt belt" probably didn't help either, Bill ;-)
> > >
> > > Some suggested alternatives in the design would be:
> > > 1. use an alloy more resistant to stress corrosion cracking, and
> include
> > > ferrous alloys in the selection process
> > > 2. counterbore for a steel nut so that the aluminum bracket doesn't
> have
> > > to be threaded and therefore be more susceptible to stress/corrosion.
> > > 3. the existing counterbores for bolts to the strut housing could
> > > have a larger radius applied with a ball mill to minimize stress
> > > raisers.
> > >
> > > Perhaps the redesigned brackets have some improvements in these or
> other
> > > areas.
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