RE: Big Red Stuff 2

["Mark Nelson" <tahoe@msn.com>]

> Not being a fan of spacers (especially in race cars), I don't
> recommend at all
> this avenue.  Best to do it right.   Also, spacers can create
> problems with
> fenders pretty quickly.  Trading one problem for another.

Spacers are pretty common on some cars...especially older 911's, including
Turbos that need to clear the calipers.  The spacers really
aren't_that_thick.  We've not seen failures with smaller sized wheel
spacers.

> No Mark, it has to do with the side of the caliper hitting the
> spokes, not the
> ends of the caliper hitting the wheel.  The caliper is too thick, not too
> long.

Yes I know, I just worded my comment poorly.

> The exception, not the rule.  Even some wheels without the step,
> have a spoke
> design problem, Borbets included (not the "C")

Some Borbet's possibly may not fit, but the "C" which I have a set of, and
the "T's" will clear the big calipers for sure.

> The point is, that an 11.5 rotor and the "compact" 4 pot did not
> clear a 16,
> but did the SQ 15's.  Just proceed with caution and homework.

Your spokes were simply too close to the caliper.  That's easily
alleviated...if you choose not to use spacers, then you're going to have to
find another solution.  A 5mm spacer would cure your rubbing problem though.

> Maybe, depends on the size of the caliper and it's thickness.
> Again, I don't
> advocate wheel spacers, that's a bandaid.  When racing or
> performance driving,
> wheel spacers are a PITA and add another item to fail, not to
> mention that the
> length of the stud/bolt becomes really long.  Shear strength becomes a big
> issue.  BTST.

The wheel studs are 911 9/16th studs that have a 12.9 rating.  They aren't
easy to sheer off...we had these on our Porsche 911 SCORE Class 5 car, and
NEVER broke a stud.  Again, whether or not you choose to use wheel spacers
is your choice.

> Agree, the 993tt and the 928 caliper is not the same.  My point
> is, that you
> don't want to change rotor diameter for a given application.  You
> run into a
> couple of problems, pads need to be custom ground for your rotor
> change, and
> you can run out of hub trying to lower the caliper too far.

The pad on the big red and 928 caliper can't even cover the entire surface
area, so the easiest thing to do is put the rotors on a lathe and cut them
down to a smaller diameter.  I've since abandoned the idea of the Porsche
stuff.

> Get your own hats machined Mark.  Then you can get it the way you want it.

We've considered it, but it's an expensive proposition.  I'd like to see if
there's any other shallow hats available first. My dad's friend Andy
Porterfield (owns Porterfield brakes) is trying to find us a solution.

> Not sure how to talk you out of spacers for a  high hp
> rally car,
> but I sure would like to.  Doug Shepard used to shear the 4 bolts off the
> wheels in his GLH turbo rally car (1984), the main reason Dodge
> switched to a
> 5 bolt wheel for all turbo cars in 1985>.  Do it right the first time.

I respect your opinion, but we don't feel there's much of a strength issue
with a small spacer.  Our opinions simply differ on this issue.  Also note
that the wheel stud diameter on the GLH is pretty small, and I'm not sure
that the strength rating is as high as the Porsche studs.

cya!
-mark nelson
mailto:tahoe@msn.com
http://www.quattrosport.com