X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Wed, 28 Sep 2005 12:46:13 -0400 Message-ID: X-Original-Return-Path: Received: from imo-d23.mx.aol.com ([205.188.139.137] verified) by logan.com (CommuniGate Pro SMTP 5.0c3) with ESMTP id 740323 for lml@lancaironline.net; Wed, 28 Sep 2005 09:38:27 -0400 Received-SPF: pass receiver=logan.com; client-ip=205.188.139.137; envelope-from=REHBINC@aol.com Received: from REHBINC@aol.com by imo-d23.mx.aol.com (mail_out_v38_r5.5.) id q.103.6aaa33d3 (3948) for ; Wed, 28 Sep 2005 09:37:20 -0400 (EDT) From: REHBINC@aol.com X-Original-Message-ID: <103.6aaa33d3.306bf690@aol.com> X-Original-Date: Wed, 28 Sep 2005 09:37:20 EDT Subject: Re: [LML] Re: Drilled Brake Rotor X-Original-To: lml@lancaironline.net MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="-----------------------------1127914640" X-Mailer: 9.0 Security Edition for Windows sub 5200 X-Spam-Flag: NO -------------------------------1127914640 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit Craig, There probably is some improvement in heat rejection rate with drilled rotors. It is also true that many racing brake systems heat to very high temperatures (just watch a night road race and the glowing rotors). However, airplanes and race cars use brakes very differently. As the original post said, airplanes typically stop only once before the brakes are allowed to cool completely. Race cars use the brakes repetitively without allowing time to completely cool. Thus, cooling ducts and anything else you can do to get rid of even a little heat between applications is important in a road race car. If you only have to stop once, heat rejection will have much less benefit because the braking event will end shortly after the brakes have become hot. The main benefit of holes or slots is to allow the gasses evolved from the hot pads an escape path so that the pad stays in contact with the rotor. If you are experiencing brake fade, this may help quite a bit. If the brakes continue to work well from touchdown to stop without slots/holes, little will be gained from adding them. Rob -------------------------------1127914640 Content-Type: text/html; charset="US-ASCII" Content-Transfer-Encoding: quoted-printable
Craig,
 
There probably is some improvement in heat rejection rate with drilled=20 rotors. It is also true that many racing brake systems heat to very high=20 temperatures (just watch a night road race and the glowing rotors).
 
However, airplanes and race cars use brakes very differently. As the=20 original post said, airplanes typically stop only once before the brakes are= =20 allowed to cool completely. Race cars use the brakes repetitively without=20 allowing time to completely cool. Thus, cooling ducts and anything else you=20= can=20 do to get rid of even a little heat between applications is important in a r= oad=20 race car. If you only have to stop once, heat rejection will have much less=20 benefit because the braking event will end shortly after the brakes have bec= ome=20 hot.
 
The main benefit of holes or slots is to allow the gasses evolved from=20= the=20 hot pads an escape path so that the pad stays in contact with the rotor. If=20= you=20 are experiencing brake fade, this may help quite a bit. If the brakes contin= ue=20 to work well from touchdown to stop without slots/holes, little will be gain= ed=20 from adding them.
 
Rob
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