I've been following this thread, and while I don't know much about Trans Am
brakes in specific, I've just been through some M/C size issues on my car.
A smaller M/C bore size gives softer brake feel, at the expense of greater
pedal travel. Larger sizes give a harder feel, with less travel (the
proverbial rock hard pedal if you go too far). The effect at the caliper
end is the inverse, since what you're doing is playing with bore ratios.
The smaller cylinder can create higher line pressures than the larger one,
since it has a smaller surface area to generate the pressure. But it has to
move farther to displace the fluid required to actually move the slave
cylinders. You can get the same effect by changing the pedal ratio - more
leverage equals higher pressures and longer movement for a given amount of
force.
Keep in mind also that twin M/C divide the pedal force, while tandem (dual
in-line) M/C give all the force to both chambers of the dual M/C. This is
where the whole thing gets too complicated for me and I get the books out!
Brian
At 11:58 AM 7/13/98 -0400, you wrote:
>You are on the correct path. Go to a larger cylinder to increase the
>modulation. This decreases the pressure. It is not necessary for both
>masters to be the same size, but it is probably a good place to start.
>Doug Wilson
>
>On Sun, 12 Jul 1998, Bruce Thompson wrote:
>
>> Hello,
>>
>> I,ve been lurking in the background of the race list for a
>> while, and would appreciate some feed-back on my brake
>> system.
>> I have a '69 Firebird Trans Am race car with the JL-8 4
>> wheel disc
>> brakes. Presently there are 2 master cylinders in front of a
>> balance bar
>> and each is .75" (3/4") From here each line passes through a
>> booster,
>> with the line to the rear going through a KH bias valve.
>> I've never been a fan of rock hard pedals, I believe I can
>> modulate
>> a medium feel pedal more accurately. ( personal preference )
>> I am by no means an engineer, hydraulic, or otherwise, and
>> the books I've read suggests this should work.
>> The orig Vettes with these size brakes had 1" or 1 1/8"
>> mast/cyl depending on if they were boosted or not.
>> If any of you have any experience, comments or suggestion's
>> I would greatly appreciate your in-put.
>>
>> Thanks, in anticipation.
>>
>> Bruce Thompson.
>>
>
>
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