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Old 11-09-2012, 01:59 AM
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7" vs 8" Dual Booster

Is there that much difference between a 7" and 8" dual boosters power assist capability? I've got about 16 vacuum at idle will I gain much by switching from a 7" to an 8" dual booster?
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Old 11-09-2012, 06:35 AM
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Originally Posted by jayd_2 View Post
Is there that much difference between a 7" and 8" dual boosters power assist capability? I've got about 16 vacuum at idle will I gain much by switching from a 7" to an 8" dual booster?
You will gain about 100 psi by using the larger booster. Whether or not it will be enough to satisfy whatever the deficit is, I cannot say w/o more info.
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Old 11-26-2012, 10:39 PM
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You will gain about 100 psi by using the larger booster. Whether or not it will be enough to satisfy whatever the deficit is, I cannot say w/o more info.
Got stock S10 front disc with S10 Blazer rear disc, good stopping power would like more, was thinking about changing to an 8" dual booster. The MC is a Corvette syyle with aftermarket under-the-floor and mount/pedal.
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Old 11-27-2012, 05:15 AM
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Originally Posted by jayd_2 View Post
Got stock S10 front disc with S10 Blazer rear disc, good stopping power would like more, was thinking about changing to an 8" dual booster. The MC is a Corvette syyle with aftermarket under-the-floor and mount/pedal.
Was the caliper bore diameter taken into account when the MC was bought? I ask because there are several different 'Vette MC bore sizes available.

At least some S10 calipers were the low drag type that used the stepped bore MC. Do you have more pedal travel before braking begins than you like?

Have you looked at the pedal ratio?
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Old 11-27-2012, 06:32 AM
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The MC bore is one inch and the pedal assembly is an aftermarket under the floor. I've got 2lb residual valves on front and rear, no excessive pedal travel. Braking response is good would like a little less pedal effort.
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Old 11-27-2012, 07:32 AM
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Originally Posted by jayd_2 View Post
The MC bore is one inch and the pedal assembly is an aftermarket under the floor. I've got 2lb residual valves on front and rear, no excessive pedal travel. Braking response is good would like a little less pedal effort.
Less effort at the pedal w/more pedal travel can be done by a pedal ratio change. This is the easiest thing to try and I would do this first before changing the bore size, etc.

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Old 12-16-2012, 11:24 PM
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Just installed an 8" dual and what a difference, now I have the braking response I wanted well worth the 59.00 for the booster.
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