Greg- By my recollection (which may be faulty) of hydraulic theory, if you
take a specific traveling volume of fluid (hydraulic line), and apply the
pressure over a larger applied area (i.e. a larger piston diameter) you wind
up with less pressure per unit area, thus decreasing the braking effect
(actually the same pressure over a greater area). Anyone know for sure if
my theory of hydraulics is correct??
Mark Haynes
'65 Spitfire RMVR #162
'62 Sprite HAN6
> -----Original Message-----
> From: Greg Burrowes [SMTP:gregb@datafast.com.au]
> Sent: Saturday, May 08, 1999 11:56 PM
> To: Gavin Ivory; 'vintage race list'
> Subject: RE: beginners tech question
> Importance: High
>
> Gavin,
> Run bigger rear wheel cylinders to increase the applied pressure (bigger
> piston area generates more pressure) to the rear brake shoes and then use
> an
> adjustable pressure limiter to prevent rear wheel lock up.
>
> Our rules in Australia do not allow pressure limiters that can be adjusted
> from the driving position. We achieve the desired result by experimenting
> with wheel cylinder size. It's cheaper and just as effective. Wheel
> cylinders are very cheap.
>
> I just completed running Targa Tasmania in our race car and the brakes
> worked fine even on the damp Targa stages. No scary rear wheel lock ups
> on
> slippery mountain roads and we are running 7/8" cylinders instead of the
> original 9/16".
>
> Greg Burrowes
> GM Holden Torana XU1 #50
> Historic Touring Cars Australia
>
>
>
> -----Original Message-----
> From: owner-vintage-race@autox.team.net
> [mailto:owner-vintage-race@autox.team.net] On Behalf Of Gavin Ivory
> Sent: Saturday, 8 May 1999 5:49
> To: 'vintage race list'
> Subject: beginners tech question
>
> I think my front disc brakes [new and upgraded] are locking-up way before
> I'm getting full stopping power from my rear drums [shoes, cylinders in
> good
> shape, with no air]. I'd like to install a brake prop valve, which I
> understand gets spliced into the rear brake lines. Question is: Am I right
> in thinking that the prop valve can only decrease the pressure to the rear
> brakes, and if so, where do I install it if I want more fluid flowing to
> the
> rear brakes. Put it on the front brake lines??
> Thanks for the help,
>
> Gavin Ivory [...still pining to get into vintage race ... but in the
> meantime, learning all I can, under the car and at Mosport/Shannonville
> driving schools]
>
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