19 or 23 bore master cyl? |
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19 or 23 bore master cyl? |
broomhandle |
Jun 18 2012, 02:09 PM
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#1
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Member Group: Members Posts: 290 Joined: 26-June 09 From: Half Moon Bay, CA Member No.: 10,512 Region Association: Northern California |
19 or 23 bore?
I have a 70 with stock brakes. I was thinking 23 but unsure if I have to change anything. I know 19 is a direct fit, just wondering 23. Any thoughts? |
jmill |
Jun 19 2012, 10:27 AM
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#2
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Green Hornet Group: Members Posts: 2,449 Joined: 9-May 08 From: Racine, Wisconsin Member No.: 9,038 Region Association: Upper MidWest |
I agree. The 17mm master cylinder generates a higher clamp force than the 19mm and the 23mm MC. With the same pedal effort, yes. Add more pedal effort on the 19 or 23 and you get the same clamping force. More clamping force doesn't help you once you can lock them up. I wouldn't go with a 23mm. |
dlestep |
Jun 19 2012, 09:22 PM
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#3
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I am smilin'... Group: Members Posts: 890 Joined: 15-January 08 From: Sunrise Florida Member No.: 8,573 Region Association: South East States |
I agree. The 17mm master cylinder generates a higher clamp force than the 19mm and the 23mm MC. With the same pedal effort, yes. Add more pedal effort on the 19 or 23 and you get the same clamping force. More clamping force doesn't help you once you can lock them up. I wouldn't go with a 23mm. It's a matter of displaced hydraulic volume, and distributed pounds force per inch squared. More volume (even a tiny .080 dia change as with the 19mm) requires more pedal pressure, still with less clamping force of the 17mm. Somewhere is an article showing something like 1400 lbs (17mm) compared to 1150 lbs (19mm). For control, one doesn't want to lock the wheels. The 19mm MC demonstrates less pedal travel, hince a better pedal feel. Above all of that, the increase in surface area (pad) and caliper piston diameter demand greater pressure to achieve the same force. But the buy back, from the increased surface area and the use of better friction materials doesn't require as much pedal pressure to achieve the desired control today. One has to change not just the MC, but the caliper and friction material as well, to experience real gains. I run PMB's Aluminum Brembos, Porterfield R4-S pads, 911 vented rotors with a 19mm MC. When I have to stop quickly, I have to be aware of what is behind me. I fear being ass-ended because not very many street cars can stop as fast. |
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