re: Rear Brake Discs - GTV6 vs Alfetta

[George Graves <gmgraves@domain.elided>]

AFAIK, the rear brakes on the 4-cylinder Alfetta coupe and the similar
looking GTV-6 are the same, I.E. non-vented, single caliper Brembos. The
front brakes on the GTV-6, OTOH are different. The Brembo discs are larger
than on the 4-cylinder car and are vented.

The IAP slotted rotors for the GTV-6 front brakes are an excellent upgrade,
and a very cost effective way to increase braking performance. If one is NOT
racing one's GTV-6, replacing the stock units with multi-pot calipers is
neither a cost effective nor a performance effective upgrade. Make sure to
mate the new discs with the Frodo high-performance pads (on the facing page
of IAP's new catalogue). Aside from fitting new Frodo pads to the rear
brakes, there seems to be little advantage to upgrading the rear discs in a
non-race prepared car.

The racing Frodo pads (or any other racing pads for that matter) are NOT a
good idea on a street car. The reason is that they don't have much grip
until they are warm, which, in a race would happen very quickly.
Unfortunately, the first time you would likely need the brakes in a manner
for which they were designed, would be in a panic stop situation in traffic.
Under those conditions, the racing pads would not be up to optimum operating
temperature, and therefore would not be as good as a pad that was more of a
compromise between a racing pad and a stock pad. Stick with the intermediate
Frodo pad in this case, leave the racing pad alone!

Also, keep in mind that high performance brake pads are made from a harder
material than are the street pads. This means that it takes longer to "wear
them in" than it does for standard pads. All pads must be worn-in especially
if the disc has been replaced or turned. This process embeds brake pad
material into the microscopic pits and valleys in the disc surface, tending
to even the surface out. Until this is done, you have much less brake pad to
disc contact and braking will tend to be uneven and quite a bit less than
totally up to full braking potential.

One last point has to do with brake squeal. It is caused by the pad
vibrating against the disc. The way to eliminate it, especially on cars
fitted with slotted or cross-drilled discs, is to take a grinding wheel to
the very corners of the pad before fitting them. If you knock off the very
corner of the pad, it cannot catch on the slots or holes and therefore will
not set-up the vibration that causes the squeal. This methodology has also
proven effective on non slotted or cross-drilled discs as well. Dont knock
off too much, just enough so that the actual corner of the pad is higher
than the pad surface. Of course, you might have to do this again after the
pads have worn down to the point where the edges are again even with the
surface.

-- 
George Graves

"Friends don't let friends drive boring cars"

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