I think you'll like this, lots of pictures
10-15-2003, 02:23 PM
#1
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I think you'll like this, lots of pictures
I finally got around to redoing the BIRA brake upgrade page on the plane today, audipages should be so lucky for layovers.....anyways click the link if you want to see all the pictures of the front brake upgrade.....a few never seen before pics.....<ul><li><a href="http://www.audipages.com/upgrades/birabrakeupgrade.html">http://www.audipages.com/upgrades/birabrakeupgrade.html</a</li></ul>
10-15-2003, 02:55 PM
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Nice writeup. One thing to note though
The rotors are actually cast with the vent holes, not drilled. That's why they're a lot less prone to crack than drilled rotors.
I didn't know you could buy the hats and brackets separately. Hmm...I have a complete set of 993 brakes in the garage...
I didn't know you could buy the hats and brackets separately. Hmm...I have a complete set of 993 brakes in the garage...
10-15-2003, 03:16 PM
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Great work PaulW! One slight thing tho ;)
Monoblock calipers have gotten a lot of great PR, but the simple fact of physics is that aluminum loses *half* it's strength at 400 degrees F .. so when you are scooting around the turns at Road America, the bridges which connect the two sides of your monoblock caliper are actually less than half as strong as two piece calipers, connected by zero clearance steel rods .. steel actually gets %15 stronger at 400F!!
The *real* reason manufacturers like monoblock is that after the machine tools are paid for, they are actually a lot cheaper to make than two piece calipers.
The *real* reason manufacturers like monoblock is that after the machine tools are paid for, they are actually a lot cheaper to make than two piece calipers.
10-15-2003, 04:41 PM
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Well ...
This from a Brembo employee, "SilverSnake", in this <A HREF="http://corner-carvers.com/forums/showthread.php?s=&threadid=11646">Corner Carvers Thread</a>. See page 2 in particular.
"However, one intersting item is that all of our X-drilled holes are exactly that ... drilled ... even the Porsche ones. Its a bit of an urban legend that Porsche 'casts-in their holes' for strength. Truth is, when I started with Brembo I thought the same thing. I mentioned it to our Italian resident Applications Engineer. I was kinda surprised myself. He laughed and added, 'People seriously think we cast in all of the holes? Wow, I'd love to see the mold for that! No, actually they are all drilled and chamfered post-casting."
And this Porsche rotor sure looks drilled to me.
<img src="http://www.JonAadland.com/Movit7.JPG">
"However, one intersting item is that all of our X-drilled holes are exactly that ... drilled ... even the Porsche ones. Its a bit of an urban legend that Porsche 'casts-in their holes' for strength. Truth is, when I started with Brembo I thought the same thing. I mentioned it to our Italian resident Applications Engineer. I was kinda surprised myself. He laughed and added, 'People seriously think we cast in all of the holes? Wow, I'd love to see the mold for that! No, actually they are all drilled and chamfered post-casting."
And this Porsche rotor sure looks drilled to me.
<img src="http://www.JonAadland.com/Movit7.JPG">
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10-15-2003, 05:13 PM
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Well ...
Agree, aluminum does have about 1/2 the tensile strength of steel, and at 400 oF it may be down to 1/4, but ... the aluminum bridges of monobloc calibers have probably 10x the cross sectional area of the 4 bolts of a 2-piece caliper. 10/4 ==> the monobloc is still 2.5x stronger.
Also, we probably should be talking about modulus of elasticity not tensile strength, and aluminum monobloc calipers are usually very rigid aluminum/ceramic composites. In the end, probably the only way to know whether one caliper is more rigid than another is to test both, and I've never seen any test results.
Brembo 4-pot (two cap screws, above & below left bleed screw)
<img src="http://www.audipages.com/Tech_Articles/susp_whls_brake_steer/S8brake1.JPG">
Porsche 4-pot monobloc
<img src="http://www.audipages.com/upgrades/bira1.JPG">
Alcon 6-pot monobloc
<img src="http://pictureposter.audiworld.com/17157/alconta6_a.jpg">
Also, we probably should be talking about modulus of elasticity not tensile strength, and aluminum monobloc calipers are usually very rigid aluminum/ceramic composites. In the end, probably the only way to know whether one caliper is more rigid than another is to test both, and I've never seen any test results.
Brembo 4-pot (two cap screws, above & below left bleed screw)
<img src="http://www.audipages.com/Tech_Articles/susp_whls_brake_steer/S8brake1.JPG">
Porsche 4-pot monobloc
<img src="http://www.audipages.com/upgrades/bira1.JPG">
Alcon 6-pot monobloc
<img src="http://pictureposter.audiworld.com/17157/alconta6_a.jpg">
10-15-2003, 07:01 PM
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You mean rotor, right? ;)
Interesting thread there. That's the first I've heard to refute that the holes are actually drilled. I'd love to see how the Porsche guys would react to that message. I had a '98 911 and the factory rotors sure did stand up to stress cracking compared to aftermarket "cross-drilled" rotors.
The picture of the rotor actually looks like the holes are cast to me and then cleaned up on the faces. In fact, in the thread, one guy follows up by saying,
"If you look at the first pic I posted, it's clear the holes have at least been cleaned up where they go through the faces, but it's also very clear that where the holes cut into the main cooling vanes along their entire length is "as cast." But I suppose it's impossible to tell from looking if the hole through the faces was just "cleaned up" or drilled completely. Hmmm."
Later "SilverSnake" does admit that some of his facts aren't straight. Now, he may be right after all about the drilling but then again you never know what to believe on the internet. To each his own.
The picture of the rotor actually looks like the holes are cast to me and then cleaned up on the faces. In fact, in the thread, one guy follows up by saying,
"If you look at the first pic I posted, it's clear the holes have at least been cleaned up where they go through the faces, but it's also very clear that where the holes cut into the main cooling vanes along their entire length is "as cast." But I suppose it's impossible to tell from looking if the hole through the faces was just "cleaned up" or drilled completely. Hmmm."
Later "SilverSnake" does admit that some of his facts aren't straight. Now, he may be right after all about the drilling but then again you never know what to believe on the internet. To each his own.