{"id":1944,"date":"2013-12-26T08:00:58","date_gmt":"2013-12-26T16:00:58","guid":{"rendered":"http:\/\/www.racingjunk.com\/news\/?p=1944"},"modified":"2016-11-30T15:27:48","modified_gmt":"2016-11-30T23:27:48","slug":"what-you-should-know-about-drag-race-brakes-rotors","status":"publish","type":"post","link":"https:\/\/www.racingjunk.com\/news\/what-you-should-know-about-drag-race-brakes-rotors\/","title":{"rendered":"What You Should Know About Drag Race Brakes: Rotors"},"content":{"rendered":"

\"Drag<\/a><\/p>\n

Brakes in a drag race car are incredibly important. Stopping your race should be top priority, but staging it with ease is another. This guide to drag race brakes will help identify the components, and assist you with choosing the right parts for YOUR setup.<\/p>\n

Brake Rotors<\/strong><\/h4>\n

There are a number of different rotors (race and otherwise) in production today.\u00a0 For most common applications, two or three\u00a0different types see regular use:\u00a0 Solid steel and iron rotors are the most common, with more exotic carbon rotors coming in third. (Occasionally, you’ll find vented steel rotors in certain applications, but we’re not going to look at those). \u00a0So which one is best?\u00a0 That depends upon your project and your pocket book.<\/p>\n

As mentioned above, solid rotors can be manufactured from steel or gray cast iron.\u00a0 Both have their merits, but in the end, a rotor must have good wear and friction properties.\u00a0 It also must be rigid and have sufficient strength at high temperatures.\u00a0 Rotors are measure by the outside diameter as well as the total thickness across the pair of contact surfaces.\u00a0 Obviously, a vented rotor will always be thicker and in most cases, far heavier than a solid example.\u00a0 In terms of diameter, the rotor is always limited by the size of the wheel (this is important in most drag race applications, since the vast majority of wheels are constructed with a fifteen inch diameter).<\/p>\n

How important is the size of the rotor?\u00a0 Very.\u00a0 The swept area of the brake eventually determines the stopping capability.\u00a0 Swept area is the total area contacted by both the inner and outer pads as the rotor makes one complete revolution.\u00a0 As you can see, if the rotor (and pads) is made larger, then the swept area increases.\u00a0 Remember, wheel size is definitely the limiting factor.<\/p>\n

When you examine some rotors (such as the Mark Williams Enterprises pieces shown in the accompanying photos), you’ll see that the steel rotors have been machined with grooves or slots on the contact surface.\u00a0 The purpose of these slots is to eliminate dust buildup between the pad and the rotor.\u00a0 In an oval track or road race application, slots are often used to eliminate gas buildup between the rotor and the brake pad (which might cause brake fade), but this is seldom an issue in a drag race application, or even in a street car application for that matter.\u00a0 The slots or grooves simply provide an escape route for the dust particles.\u00a0 What about drilling holes in the rotor instead of machining slots?\u00a0 Like rotor materials, drilling has merits and pitfalls.\u00a0 First and foremost is the fact that different rotors respond differently to drilling.\u00a0 Solid cast iron rotors are very prone to cracking, and because of this, they should not be drilled.\u00a0 Steel rotors, on the other hand, can be successfully drilled with no side effects (provided the “drilling” process is handled by someone who knows what they’re doing).\u00a0 While it’s not unusual to find drilled solid rotors, you may have read reports where drilled rotors crack between lightening holes (typically cast iron rotors).\u00a0 The one thing you should remember is that cracking is almost always experienced in applications where brakes are used constantly during the duration of the event (road racing is a good example).\u00a0 In the end, steel<\/span> rotors manufactured from a suitable, properly heat treated alloy and properly lightened (with machined holes) by an experienced manufacturer are perfectly suitable for many applications.<\/p>\n

Remember when we mentioned the cost of rotors?\u00a0 If cost is no object or if you race in a class where unsprung weight is absolutely critical then the need for a lighter, more “powerful” rotor becomes much more important.\u00a0 That’s where today’s carbon rotors enter the equation.\u00a0 Originally developed for heavy aircraft brakes, this rotor material first saw service in Formula One competition before being introduced to other forms of motorsports.\u00a0 The idea behind a carbon rotor is that it is extremely light in weight and extremely effective.\u00a0 As an example, the first Formula One tests saw rotor temperatures of almost 930\u00b0 C (over 1700\u00b0 F), with no brake component damage.\u00a0 Obviously, this type of rotor material will deliver superior stopping power.<\/p>\n

According to Mark Williams, “Carbon\/Carbon brakes do not suffer brake fade at elevated operating temperatures as with normal friction material. With Carbon\/Carbon the friction coefficient actual increases as the temperature increases.\u00a0 Carbon\/Carbon brakes are unique in the fact that both the disc (rotor) and the pad are made of the same material”.\u00a0 Mark points out something very important in the design of carbon rotors:\u00a0 “We use a square drive lug system which allows for the expansion of the aluminum mounting adapter”.\u00a0 Why is this so important?\u00a0 Simple.\u00a0 The heat dissipated by the carbon rotor can become so great that the aluminum mount can expand considerably (carbon shows very little expansion at elevated temperatures).\u00a0 The square drive “lugs” allow for this expansion that in turn allows the brake dimensions to remain stable under extreme heat conditions (more on this later).<\/p>\n

Mark Williams also points out that Carbon\/Carbon technology has changed dramatically over the past few years.\u00a0 Currently, M-W uses a laminated 2D carbon fiber knit Carbon\/Carbon that is infinitely superior to the more common chopped fiber material that was so common several years ago.<\/p>\n

How much different are the weights of various rotor configurations?\u00a0 You might be surprised.\u00a0 The following chart depicts the weight of various Mark Williams rotors (all with the same 11.75 inch diameter):<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Description\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Weight<\/b><\/p>\n

_____________________________________________________________<\/p>\n

\u2022\u00a0\u00a0\u00a0\u00a0 .810-inch thick-vented rotor \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 8.05 pounds<\/p>\n

\u2022\u00a0\u00a0\u00a0\u00a0 Steel with cleaning grooves\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 6.90 pounds<\/p>\n

\u2022\u00a0\u00a0\u00a0\u00a0 Steel with lightening holes\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 6.10 pounds<\/p>\n

\u2022\u00a0\u00a0\u00a0\u00a0 Carbon\/Carbon \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 2.00 pounds<\/p>\n

 <\/p>\n

As you can see, the weight of the rotor can be reduced significantly by using exotic materials.\u00a0 By drilling the rotors, it is possible to remove almost a pound from each wheel.\u00a0 Keep in mind that the above rotors are all from Mark Williams.\u00a0 Other manufacturers will have different weights for their specific products.<\/p>\n

So far so good. But what about hats, calipers and brake pads and other components?\u00a0 Hold on!\u00a0 We\u2019ll look at those components in an upcoming segment of The Burnout<\/i>.\u00a0 Meanwhile, check out the photos that follow:<\/p>\n

\"Complete<\/a>
This is a complete brake package from Mark Williams. The front brake system is based upon a four piston caliper and a solid rotor while the rear setup is one of M-W\u2019s Pro Street packages. It includes a four piston caliper and a vented rotor. Not shown is a single piston mechanical caliper.<\/figcaption><\/figure>\n
\"<\/a>
This front brake package from Mark Williams Enterprises is based upon a solid steel rotor mated to an aluminum hat\/hub combination. We\u2019ll dig deeper into hubs in the next segment.<\/figcaption><\/figure>\n
\"Mark<\/a>
Rear brake hats are tripled drilled \u2013 4.5-inch, 4.75-inch and 5.0-inch wheel bolt patterns. Obviously, the pattern in your axle dictates the pattern you\u2019ll use. Needless to say, this is a very nice, light arrangement. By the way, the rear rotor shown here is a heavy duty Pro Street vented job offered by Mark Williams.<\/figcaption><\/figure>\n
\"Mark<\/a>
Brake rotors are available in a number of different configurations. This rear brake setup from Mark Williams Enterprises consists of an aluminum hat section along with a vented steel rotor. Typically, rotors can be manufactured from steel (such as these pieces), iron or Carbon. Which is best? The answer is totally dependent upon the application and your wallet. As an example, Carbon\/Carbon brakes are very light, very effective and expensive. Obviously, costs with iron or steel rotors are significantly less.<\/figcaption><\/figure>\n
\"Mark<\/a>
Up close, you can see how Mark Williams machines grooves into their steel brake rotors. Why is this done? Simple. It provides an escape route for brake pad dust (which is inevitable whenever you apply the brakes). In an oval track or road race application, slots are often used to eliminate gas buildup between the rotor and the brake pad (which might cause brake fade), but this is seldom an issue in a drag race application. The slots or grooves simply provide an escape route for the dust particles.<\/figcaption><\/figure>\n

This series continues here: Part 2<\/a><\/p>\n

—————————————————————————————————————————————<\/p>\n

\"Wayne\"<\/a><\/p>\n

About the author: Wayne Scraba is a racecar junky.\u00a0 His background includes operation of his own speed shop, building racecars (some you might be familiar with, but we won\u2019t get into it here), building hot rod street machines; he\u2019s built custom motorcycles, restored muscle cars and played with off road bikes. Scraba has a sundry background in writing too:\u00a0 He\u2019s toiled as a magazine Editor, a technical Editor, a free-lance magazine contributor and authored five automotive books. His byline (well over 4,500 articles worth) has appeared in well over sixty different high performance automotive, motorcycle and aviation magazines worldwide.\u00a0 Racecar junky?\u00a0 Most likely!<\/em><\/p>\n

 <\/p>\n

—————————————————————————————————————————————<\/p>\n","protected":false},"excerpt":{"rendered":"

Learn how to choose the best brakes and brake components for your drag race vehicle. Part 1 focuses on rotors.<\/p>\n<\/div>","protected":false},"author":20,"featured_media":1950,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_publicize_message":"","jetpack_publicize_feature_enabled":true,"jetpack_social_post_already_shared":true,"jetpack_social_options":{"image_generator_settings":{"template":"highway","default_image_id":0,"font":"","enabled":false},"version":2}},"categories":[5009,11,9],"tags":[323,4316,320,4317,318,319,322,1594,4318,461,321],"class_list":["post-1944","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-brakes","category-how-tos","category-tech-tips","tag-brake-install","tag-brake-rotors","tag-brake-series","tag-brake-setup","tag-brakes","tag-drag-brakes","tag-install","tag-staging","tag-stopping","tag-tech-tips-2","tag-wayne-scraba"],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"https:\/\/www.racingjunk.com\/news\/wp-content\/uploads\/2013\/12\/Brake-Lead-Feature.jpg","jetpack_shortlink":"https:\/\/wp.me\/p42YSK-vm","jetpack_sharing_enabled":true,"amp_enabled":true,"_links":{"self":[{"href":"https:\/\/www.racingjunk.com\/news\/wp-json\/wp\/v2\/posts\/1944","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.racingjunk.com\/news\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.racingjunk.com\/news\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.racingjunk.com\/news\/wp-json\/wp\/v2\/users\/20"}],"replies":[{"embeddable":true,"href":"https:\/\/www.racingjunk.com\/news\/wp-json\/wp\/v2\/comments?post=1944"}],"version-history":[{"count":11,"href":"https:\/\/www.racingjunk.com\/news\/wp-json\/wp\/v2\/posts\/1944\/revisions"}],"predecessor-version":[{"id":27140,"href":"https:\/\/www.racingjunk.com\/news\/wp-json\/wp\/v2\/posts\/1944\/revisions\/27140"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.racingjunk.com\/news\/wp-json\/wp\/v2\/media\/1950"}],"wp:attachment":[{"href":"https:\/\/www.racingjunk.com\/news\/wp-json\/wp\/v2\/media?parent=1944"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.racingjunk.com\/news\/wp-json\/wp\/v2\/categories?post=1944"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.racingjunk.com\/news\/wp-json\/wp\/v2\/tags?post=1944"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}