Stoptech or brembo???
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Joined: Feb 2002
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That's not why they use different piston sizes. They match factory brake torque ...
... in order to provide optimium balance. This keeps stopping distances as short as possible and prevents negative interactions with ABS and dynamic stability control systems.
Brake torque is a function of rotor effective radius, clamping force, and pad coefficient of friction. When StopTech makes two kits for the same platform, one with a bigger rotor (e.g., 332mm and 355mm) the kit with the bigger rotor will get smaller pistons in order to maintain the same brake torque.
For a description of how they go about selecting pistons sizes, you should check out an article I wrote after helping them test their new (at the time) kits for the Nissan 350Z: <a href="http://www.zeckhausen.com/Testing_Brakes.htm">http://www.zeckhausen.com/Testing_Brakes.htm</a>
The article gives you all sorts of background information on how the piston sizes are selected and then demonstrates how it affects stopping distances with real world data. I think you'll find it an interesting read.
Dave Zeckhausen
Brake torque is a function of rotor effective radius, clamping force, and pad coefficient of friction. When StopTech makes two kits for the same platform, one with a bigger rotor (e.g., 332mm and 355mm) the kit with the bigger rotor will get smaller pistons in order to maintain the same brake torque.
For a description of how they go about selecting pistons sizes, you should check out an article I wrote after helping them test their new (at the time) kits for the Nissan 350Z: <a href="http://www.zeckhausen.com/Testing_Brakes.htm">http://www.zeckhausen.com/Testing_Brakes.htm</a>
The article gives you all sorts of background information on how the piston sizes are selected and then demonstrates how it affects stopping distances with real world data. I think you'll find it an interesting read.
Dave Zeckhausen
AudiWorld Member
Joined: Feb 2002
Posts: 115
Likes: 0
All else being equal, a monobloc caliper will flex more than a 2-piece ...
... caliper. That's because the steel through-bolts are stronger than the aluminum castings.
When Porsche transistioned from the 993 to the 996 platform, they went to monobloc calipers in order to reduce manufacturing cost. In order to compensate for the weaker material in the bridge, they made the caliper MUCH thicker in the top. You can see it for yourself by comparing the sleek looking 993TT calipers with the chunky, blocky looking monoblocs on the new Turbo.
I'm sure the calipers on the new car are just as stiff as the old calipers, but that's because they compensated by adding material. If you were to use a monobloc caliper as the basis for a brake kit, you would typically need a wheel size 1" larger diameter than would be required for 2-piece calipers for any given rotor size because of the thicker bridge.
Here's a pretty comprehensive article on the subject: <a href="http://www.stoptech.com/whitepapers/monobloc3.htm">http://www.stoptech.com/whitepapers/monobloc3.htm</a>
Dave Zeckhausen
When Porsche transistioned from the 993 to the 996 platform, they went to monobloc calipers in order to reduce manufacturing cost. In order to compensate for the weaker material in the bridge, they made the caliper MUCH thicker in the top. You can see it for yourself by comparing the sleek looking 993TT calipers with the chunky, blocky looking monoblocs on the new Turbo.
I'm sure the calipers on the new car are just as stiff as the old calipers, but that's because they compensated by adding material. If you were to use a monobloc caliper as the basis for a brake kit, you would typically need a wheel size 1" larger diameter than would be required for 2-piece calipers for any given rotor size because of the thicker bridge.
Here's a pretty comprehensive article on the subject: <a href="http://www.stoptech.com/whitepapers/monobloc3.htm">http://www.stoptech.com/whitepapers/monobloc3.htm</a>
Dave Zeckhausen
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