slave cyl size

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chevyfreak
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slave cyl size

Post by chevyfreak » Mon Feb 16, 2015 5:49 am

Hi.
just a question of curriosity what happens if you enlarge rear slave cyl on the brakes?
lets say its one inch.. and you step it up to 1 1/8.
for discussion sake rest of system stays the same.
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governor
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Re: slave cyl size

Post by governor » Mon Feb 16, 2015 8:37 am

You loose some pressure when going larger, what are you trying to accomplish?

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Re: slave cyl size

Post by chevyfreak » Mon Feb 16, 2015 10:58 am

Hi. Its not me its my one buddy. He fitting a 12bolt diff into one of his cars and the slaves are totally ruined. He's got a set slaves he wants to use but its 1/8 bigger in the pistons.
i was thinking there was gonna be a bit of less pressure on the pedal but wasnt sure if someting else was gonna happen. System has no power assist and drums in front as well,
thanks for reply.
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governor
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Re: slave cyl size

Post by governor » Mon Feb 16, 2015 1:46 pm

You mean the rear wheel Cyl, not the slave or master cyl. If you are talking axle wheel cyl larger then pressure should not change much.

I re-read your post and realized your term was a little different than what I was used to, LOL

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chevyfreak
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Re: slave cyl size

Post by chevyfreak » Mon Feb 16, 2015 2:56 pm

Hi , im from south africa and the 'lingo' here is way different than anywhere else, sorry for the misunderstanding caused. If i start talking the american way of headers ,oil pans and stuff the petrol heads here think im weird,lol. :lol:
Thanks for the help.
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governor
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Re: slave cyl size

Post by governor » Mon Feb 16, 2015 3:26 pm

Some sprint car racers I know from United States who are from Michigan have made trips to race in your area the last few years, did you happen to attend
any of those races?

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dave brode
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Re: slave cyl size

Post by dave brode » Mon Feb 16, 2015 3:29 pm

Give me a reality check if need be.

Doesn't the pressure coming from the master say the same? And, doesn't that pressure on a wheel cyl [slave] with more piston area result in MORE force on the shoes?

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Re: slave cyl size

Post by governor » Mon Feb 16, 2015 3:56 pm

The PSI would not change from the master cyl, but I believe the pedal would stroke a little farther to fill the added sq inch of the larger wheel cyl.

I very sure the pressure at the wheel cyl would not change, but maybe someone who has more Hyd pressure knowledge will chime in here.

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Re: slave cyl size

Post by Baprace » Mon Feb 16, 2015 8:59 pm

dave brode wrote:Give me a reality check if need be.

Doesn't the pressure coming from the master say the same? And, doesn't that pressure on a wheel cyl [slave] with more piston area result in MORE force on the shoes?
You are correct, with a bigger bore wheel cylinder and everything else remains the same size bore you will have more pressure/force on the shoes or more clamping on pads if it is a disc brake system.

Governor is also correct.

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Re: slave cyl size

Post by chevyfreak » Tue Feb 17, 2015 12:50 am

governor wrote:Some sprint car racers I know from United States who are from Michigan have made trips to race in your area the last few years, did you happen to attend
any of those races?

Gov
Hi yes i did , was an experience seeing how their setup on sprints against ours. And i know our top driver also went over to your side to race.
over here there are few things that screams like a sprint ,only other would be the rotaries.
Thanks to all the replies i will forward it to my buddy and will see what happens but i still think he should be fine with it.
thanks
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Re: slave cyl size

Post by BigBlocksOnTop2 » Wed Feb 18, 2015 8:55 am

You will have a little longer stroke on the pedal. The master cyclinder will still put out the same pressure. You will have more force on the shoes.

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Re: slave cyl size

Post by Olefud » Fri Feb 20, 2015 12:37 pm

I bored out the rear slave cylinders on my road racer to increase the rear bias -all other things kept the same.

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Re: slave cyl size

Post by chevyfreak » Fri Feb 20, 2015 12:48 pm

Olefud wrote:I bored out the rear slave cylinders on my road racer to increase the rear bias -all other things kept the same.
In effect its exactly what my friend is doing buzy now helping him fitting cylinders and new brake shoes and all. This is all on a pontiac parisienne. Which here in south africa came out with chevy drivetrain. 327 powerglide and 12bolt c clip diff 3.07 ratio. Its a big car so i dont think there will be any issues with locking up the rear wheels.
thanks for all the input guys.
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