Re: Some info on GTV6 Track Brakes

[Nathan Wong <alfacors@domain.elided>]

>Date: Thu, 18 Mar 1999 16:42:16 -0500
>From: Gerry Lehmann <lehmann@domain.elided>
>Subject: Some info on GTV6 Track Brakes

Hi Garry

>The short story for a GTV6.....Its all in the
>rear!

I think this is true for ANY Alfetta without an adjustable brake balance valve.

>The solution. Based on the above, I wrapped =
>the rear exhaust with header wrap, slotted =
>the rear rotors and installed a proportioning =
>valve to move a bit of the braking chores =
>frontwards.  (The latter is the right thing =
>to do with sticky tires anyway, because with =
>the extra adhesion of track tires you also =
>have more weight transfer than the stock car =
>was ever designed for and will tend to lock =
>the rears early.)  The result.....I've had =
>no brake problems since.

We use a Tilton brake balance valve, which uses a lever rather than a
twist-knob for selecting the balance. It's not as finely tuneable as the
knob version, but it was cheaper and does the job. We found the same as you,
except that our rears would bind up after some heavy racing, to the extent
that when the rear was jacked up, you could not turn the rear wheels by hand!
We solved the problem of the rear exhaust heat by changing the exhaust to
hang out the side of the car (impractical and illegal for a roadcar though).
We also used some foil ducting under the car to direct air towards the rear
discs. While it is not totally effective, the airflow to the discs IS
improved slightly, and helps to cool the brakes somewhat (especially when
racing for an hour or more). Most people use the aircraft-style tubing,
which is a type of rubber sheath over a wire coil insert. Quite strong, and
very flexible, but nice and smooth inside to help airflow and reduce
turbulence. Cost is a little prohibitive though. Thats why we used the Foil
one instead on the rear, and saved the aircraft one for the front (When we
get around to doing them).
Fluid is AP Racing 550, pads are switched between the old Ferodo DS11 and
the newer 3000 series compound (much softer, but cold braking much better).
Front V6 discs are slotted, rears are not.

Cheers,
- --
Nathan Wong             http://www.nectar.com.au/~alfacors
                      Alfa Romeo - Super Touring - Club Cars
AlfaCors@domain.elided       V8Supercars - Formula One - CART

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