DeTomaso Mailing List: December 99, Message #454

I'd like to learn a little more on this topic.  I run 4 piston Wilwood
calipers front and rear.  With 225 R1s in front and 255s in the rear, I
sense front wheel lock up well prior to the rears.  When the tires are cold,
the fronts lock up even earlier.  Unfamiliar with Wilwoods when I installed
them and sensitive to the danger of premature rear wheel lockup,  I mounted
my proportioning valve in the rear brake line.  In this position, it is
useless as no restriction to the rear brakes, even in the wet, is warranted.
I'm curious:

Can anyone with Wilwoods on this list prematurely lock their rear brakes
with out a proportioning valve on the front side?  What size tires are you
using if yes?

If I move my Wilwood adjustable prop valve to the front side, will it only
assist in the initial stage of braking? As Steve C.points out, "as the line
is still a continuous flow, it just takes an extra microsecond for the
system to equalize and the proportioning valve is non functioning after
that."

Do I need to go to a dual master to get better bias?

What solutions to this issue are others employing, or are you ignoring it?

J, getting ready to replumb his brake lines, T


-----Original Message-----
From: Tony DiGiovanna <t.digiovanna@mindspring.com>
To: Multiple recipients of list <detomaso@realbig.com>
Date: Monday, December 13, 1999 4:32 PM
Subject: Re: Brake mods


>Tomas,
>
>This is news to me.  How does one distinguish between prop valves that work
>statically, and those that don't?  This feature appears quite desirable.
>What is the mechanism that is deployed internally?
>
>-----Original Message-----
>From: Tomas Gunnarsson <Tomas.Gunnarsson@eu.pnu.com>
>To: Multiple recipients of list <detomaso@realbig.com>
>Date: Monday, December 13, 1999 3:22 AM
>Subject: Re: Brake mods
>
>
>>     Steve,
>>
>>     It may depend on what design your prop valve uses, but the type used
>>     on normal street cars will work in the static condition too , not
just
>>     in the initial application stage. They work with zero fluid flow too.
>>
>>     Tomas
>>
>>
>>______________________________ Reply Separator
>_________________________________
>>Subject: Brake mods
>>Author:  "Steve (AIA)" <STEVE@AIAELPASO.COM> at Internet-europe
>>Date:    1999-12-10 14:51
>>
>>
>>This is a multi-part message in MIME format.
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>>I just wanted to pass along a tidbit of info that came from a good =
>>friend of mine who is an auto engineer..
>>(with all the discussions regarding brakes),  "using a proportioning =
>>valve only assist in the initial stage of braking, as the line is still =
>>a continuous flow, it just takes an extra microsecond for the system to =
>>equalize and the proportioning valve is non functioning after that.  It =
>>only affect the initial stab of the brake pedal, preventing overbraking =
>>immediately to the wheels with less loading.  To provide a constant =
>>disproportionment of the brake system, a dual master cylinder set up =
>>with bore sizes corresponding to the needs of the system, will provide a =
>>better distribution to the rear brakes, (or front brakes, depending on =
>>how you look at it), and is a more appropriate system for high =
>>performance brake set ups."
>>My 8 pesos form EL Paso,
>>Steve R. Carvajal
>>
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>
>