{"id":4755,"date":"2014-04-10T12:09:53","date_gmt":"2014-04-10T19:09:53","guid":{"rendered":"http:\/\/www.racingjunk.com\/news\/?p=4755"},"modified":"2016-12-05T11:50:20","modified_gmt":"2016-12-05T19:50:20","slug":"star-wars-axle-housings-fabricated-ford-housings-part-i","status":"publish","type":"post","link":"https:\/\/www.racingjunk.com\/news\/star-wars-axle-housings-fabricated-ford-housings-part-i\/","title":{"rendered":"Star Wars Axle Housings Part I: Fabricated Ford Housings"},"content":{"rendered":"

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

Ford 9-inch\u00a0 rear axles are the darlings of drag racing (and other forms of racing too).\u00a0 They’ve been used in everything from the lowest class Stockers all the way up to Top Fuel dragsters.\u00a0 Unfortunately, in stock form, the Ford 9-inch housing isn’t as strong as its reputation.\u00a0 Racers were (and still are) plagued with rear axle housings that bend.\u00a0 Sure the race teams and chassis builders fortify the housings with countless braces, supports and brackets, but the massive torque loads still manage to turn even the stoutest pieces into metal spaghetti.\u00a0 In some instances, the axle housings bend and remain bent.\u00a0 In other more mysterious cases, the housings bend during the initial drag strip launch and then snap back into form as the run is completed. The reaction is very much like a huge, transverse torsion bar.<\/p>\n

Making matters worse is this:\u00a0 Today, horsepower is cheap.\u00a0 What was once exclusive Pro Stock level power is now normal performance.\u00a0 There are plenty of cars out there making huge power; and those big cars can turn a stock or poorly braced Ford housing into junk in a heartbeat.<\/p>\n

Pitfalls Of The Ford<\/b><\/p>\n

The Ford has some inherent issues.\u00a0 For example, the newest junkyard part you’ll come across has to be twenty-five years old.\u00a0 Yes you can buy \u201cnew\u201d housings but they\u2019re not perfect either.\u00a0 There are three major drawbacks to the stock 9-inch from the drag racing perspective:\u00a0 First, the housing axle tubes are not round.\u00a0 Not only do they taper from 3-1\/2-inches down to 3-inches, the tubes all have “flats” which are more or less squashed onto the tubes.\u00a0 Both of these factors force a chassis builder to custom build every bracket, because they aren’t symmetrical.\u00a0 Finally, the OEM Ford housing face is approximately 24-inches wide.\u00a0 Because of this, you have to weld brackets to the face in some cars.\u00a0 This means you lose adjustment holes for items such as the 4-link.<\/p>\n

Another problem that’s seldom discussed with Ford 9-inch housings is the rear brace.\u00a0 The almost standard brace does nothing to stop downward bending on the rather flimsy Ford housing.\u00a0 A second brace is usually needed to eliminate downward flex.\u00a0 Another point to consider is the actual rear “cover” in the housing.\u00a0 The back plate isn’t one piece (even though, at first glance it looks like a one piece affair), it’s usually pressed into the housing.\u00a0 The chassis builder is forced to weld the rear cover to the housing, but that doesn’t stop another problem:\u00a0 The hypoid action of the third member still tries to force the rear end carrier out the back of the housing.\u00a0 In order to stop this, many chassis builders weld a series of small tubes radially between the face of the housing and the rear cover plate.\u00a0 Most often called a “cage”, this apparatus stops the center portion of the housing from flexing fore and aft.<\/p>\n

So far so good. If you\u2019ve been following along and you\u2019re using a stock Ford housing, you\u2019ve already spent good dollars on the build.\u00a0 At a certain point (lets say you\u2019ve back braced it, caged the center section, added a bottom brace and straightened it, you\u2019re already into fabricated housing territory (at least from a cost point of view).\u00a0 And you\u2019re using stock old Ford parts.<\/p>\n

Something Better?<\/b><\/p>\n

With all of the cutting and pasting, the chassis builder usually begins with only the skeletal remains of the stock Ford housing, then starts from scratch.\u00a0 As you can imagine, this isn’t a very cost or time efficient way to build a rear axle housing. There has to be something better.\u00a0 And there is.\u00a0 Instead of using marginal factory components, some housings are now built entirely from scratch.\u00a0 One of the first to fabricate an all-new housing was George Cathey of Pro Designs.\u00a0 Cathey’s new, completely fabricated sheet metal housings didn’t rely upon marginal junkyard parts for the foundation.\u00a0 They didn’t bend.\u00a0 They were brutally strong and very resistant to extreme torque loads.\u00a0 And just as important, they were lighter than the heavily braced Ford 9-inch housings that were standard equipment under the quickest cars.\u00a0 Racers being racers, the advantages became immediately clear.\u00a0 Soon the housings were seen under Pro Stock cars.\u00a0 With the decidedly different shape of the housing, the drag race media quickly came up with the term “Star Wars housings”.\u00a0 While Cathey has moved on to other projects and doesn’t build housings on a regular basis, his original housings have forged a path for several new, completely fabricated housing designs.<\/p>\n

Are these new fabricated housings restricted to Pro Stock or tube frame cars only?\u00a0 Absolutely not.\u00a0 There are plenty of applications, including any number of Fast Street cars, class legal cars, Super category and ET cars that can make use of similar housings.\u00a0 Given the “trickle down effect” of drag racing, several manufacturers recognized the fact that many of these racecars had plenty of heat under the hood too.\u00a0 And much like their professional drag race counterparts, they too were twisting, bending and otherwise mangling rear end housings.\u00a0 As a result, there are countless applications that can make use of a contemporary sheet metal axle housing.<\/p>\n

Does the chassis configuration restrict the use of sheet metal housings?\u00a0 Some of the most difficult applications are those with triangulated four links. The reason is the upper links typically intrude into the narrow face of the housing.\u00a0 Companies such as TRZ Motorsports (builder of the trick housing spread out in the pages in front of you) can build a sheet metal housing for almost any Fox Mustang, GM A Body or GM G body application. These are all similar triangulated four link applications, and they can be fabricated to fit almost any width required.\u00a0\u00a0 The truth is, you don’t have to have a full tube frame Pro Stock chassis to enjoy the benefits of the fabricated housing.<\/p>\n

The TRZ housings are engineered as direct replacements and maintain original dimensions and suspension mounting points. Where they differ is in the type of link used.\u00a0 Stock setups use a bulky rubber bushing upstairs for the top link.\u00a0 TRZ revises the mounting arrangement to accept a common rod end. We\u2019ll dig deeper into the layout along with various options in the next part of this series.<\/p>\n

 <\/p>\n

\"Stars<\/a>
Stars Wars housings? As you can see by looking at this fabricated rear housing from TRZ Motorsports, the latest in rear axle housings looks nothing like a Ford 9-inch, reworked or not. There’s an incredible amount of work involved in building these components. TRZ requires at least one full week of fabrication time to build one of these pieces. While the looks are certainly space age, the level of performance is superior.<\/figcaption><\/figure>\n
\"Nothing<\/a>
Nothing in this fabricated housing is stock. The face plate is laser cut from 4130 chrome moly steel plate, and along with the back plate, is designed to accept the folded chrome moly sheet metal case and brace. As you can see, the axle tubes are anchored externally (welded into the face plate). In the following photos, you’ll see the other anchor points.<\/figcaption><\/figure>\n
\"A<\/a>
A set of bulkheads are welded inside the case. These bulkheads are designed to support the axle tubes internally. As you can see, the axle tubes (which are 3.250-inch diameter, .250-inch wall thickness, 4130 chrome moly steel) run inboard and attach to the inner bulkhead.<\/figcaption><\/figure>\n
\"The<\/a>
The tube welds also stretch horizontally into the center section. The idea is to totally prevent the axle tubes from rotating and twisting. Compare these photos with the first external view. It’s next to impossible for the axle tubes to move.<\/figcaption><\/figure>\n

Next: Part II<\/a><\/p>\n

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

Ford 9-inch\u00a0 rear axles are the darlings of drag racing (and other forms of racing too).\u00a0 They’ve been used in everything from the lowest class […]<\/a><\/p>\n<\/div>","protected":false},"author":20,"featured_media":4760,"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":[5011,11,9],"tags":[2,704,705,703,706,321],"class_list":["post-4755","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-chassis-suspension","category-how-tos","category-tech-tips","tag-drag-racing","tag-ford-housings","tag-rear-axles","tag-star-wars-housings","tag-trz-motorsports","tag-wayne-scraba"],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"https:\/\/www.racingjunk.com\/news\/wp-content\/uploads\/2014\/04\/Star-19Feature.jpg","jetpack_shortlink":"https:\/\/wp.me\/p42YSK-1eH","jetpack_sharing_enabled":true,"amp_enabled":true,"_links":{"self":[{"href":"https:\/\/www.racingjunk.com\/news\/wp-json\/wp\/v2\/posts\/4755","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=4755"}],"version-history":[{"count":5,"href":"https:\/\/www.racingjunk.com\/news\/wp-json\/wp\/v2\/posts\/4755\/revisions"}],"predecessor-version":[{"id":5053,"href":"https:\/\/www.racingjunk.com\/news\/wp-json\/wp\/v2\/posts\/4755\/revisions\/5053"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.racingjunk.com\/news\/wp-json\/wp\/v2\/media\/4760"}],"wp:attachment":[{"href":"https:\/\/www.racingjunk.com\/news\/wp-json\/wp\/v2\/media?parent=4755"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.racingjunk.com\/news\/wp-json\/wp\/v2\/categories?post=4755"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.racingjunk.com\/news\/wp-json\/wp\/v2\/tags?post=4755"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}