{"id":255,"date":"2012-06-18T10:48:53","date_gmt":"2012-06-18T14:48:53","guid":{"rendered":"https:\/\/fe3miata.com\/site\/?p=255"},"modified":"2012-06-18T12:00:21","modified_gmt":"2012-06-18T16:00:21","slug":"adjustable-cam-gears-adjusted-barely","status":"publish","type":"post","link":"https:\/\/fe3miata.com\/site\/?p=255","title":{"rendered":"Adjustable Cam Gears &#8211; Adjusted, Barely"},"content":{"rendered":"<h5><img loading=\"lazy\" decoding=\"async\" class=\"alignleft\" style=\"margin-left: 0px; margin-right: 4px;\" title=\"Adjustable Cam Gears - Adjusted, Barely\" src=\"https:\/\/fe3miata.com\/site\/wp-content\/images\/iconadjcamgears.jpg\" alt=\"\" width=\"100\" height=\"100\" \/>Adjustable cam gears provide a simple means to optimize normally aspirated cams for boost.<\/h5>\n<p><!--more--><br \/>\nThe local Miata group had a dyno day on a Mustang Dyno &#8211; three runs for cashmoney. I decided I&#8217;d play with my new Fidanza adjustable cam gears by adjusting the overlap and check power changes. I first made a baseline pull with stock cam timing for a baseline to measure the changes against.<\/p>\n<p>Stock cam timing datalog:<br \/>\n<img decoding=\"async\" class=\"alignnone\" title=\"Adjustable Cam Gears- Stock Cam Timing\" src=\"https:\/\/fe3miata.com\/site\/wp-content\/images\/FE3v1-gallery\/images\/stockcamtiming.jpg\" alt=\"\" \/><\/p>\n<p>Next cam overlap was increased resulting in a power loss throughout the entire pull. I then decreased overlap by advancing the exhaust 2\u00b0 crank (1 tick mark on the cam gear) and retarding the intake 2\u00b0. This creates a larger separation between the two valve train action (intake and exhaust.) The graphic below shows a 4 cam-degree retard on the intake and 4 cam-degree advance on the exhaust reducing overlap.<br \/>\n<img decoding=\"async\" class=\"alignnone\" title=\"Adjustable Cam Gears- Stock Cam Timing\" src=\"https:\/\/fe3miata.com\/site\/wp-content\/images\/camoverlap.jpg\" alt=\"\" \/><\/p>\n<p>The last run of less overlap made more power with less boost, while in target boost. It suffered a small loss in power at low boost during spool and hit target about 100rpm later.<\/p>\n<p>Intake -2\u00b0, Exhaust +2\u00b0 &#8211; note more power and less boost<br \/>\n<img decoding=\"async\" class=\"alignnone\" title=\"Adjustable Cam Gears- More Overlap\" src=\"https:\/\/fe3miata.com\/site\/wp-content\/images\/FE3v1-gallery\/images\/IN-2EX2camtiming.jpg\" alt=\"\" \/><\/p>\n<p>The Mustang Dyno runs above overlaid (fat lines are decreased cam overlap)<br \/>\n<img decoding=\"async\" class=\"alignnone\" title=\"Adjustable Cam Gears- Overlay\" src=\"https:\/\/fe3miata.com\/site\/wp-content\/images\/FE3v1-gallery\/images\/powercomparison.jpg\" alt=\"\" \/><\/p>\n<p>That was a start, but looks like there&#8217;s far more to do with more dyno time given the typical overlap present in OE normally aspirated cams and the amount to dial out for boost.<\/p>\n<p>Dynojet pull to show the difference in power curves vs. the above from a Mustang dyno. The only two things changed between these were installing a straight through magnaflow in place of restrictive turbo style muffler and the boost levels: dynojet ~16.5 psi average, mustang ~13.75 average after target.<br \/>\n<img decoding=\"async\" class=\"alignnone\" title=\"Adjustable Cam Gears- Mustang Dyno\" src=\"https:\/\/fe3miata.com\/site\/wp-content\/images\/FE3v1-gallery\/images\/08_1010FE3dyno.jpg\" alt=\"\" \/><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Adjustable cam gears provide a simple means to optimize normally aspirated cams for boost.<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[7],"tags":[69,70,71,72,26,22,23,17,15,25,16,18,19,24],"class_list":["post-255","post","type-post","status-publish","format-standard","hentry","category-the-first-fe3-miata","tag-adjustable","tag-adjustable-cam","tag-adjustable-cam-gears","tag-cam-gears","tag-engine-swap","tag-fe-dohc","tag-fe3","tag-mazda","tag-miata","tag-modified","tag-mx-5","tag-mx5","tag-turbo","tag-turbocharged"],"_links":{"self":[{"href":"https:\/\/fe3miata.com\/site\/index.php?rest_route=\/wp\/v2\/posts\/255","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/fe3miata.com\/site\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/fe3miata.com\/site\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/fe3miata.com\/site\/index.php?rest_route=\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/fe3miata.com\/site\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=255"}],"version-history":[{"count":10,"href":"https:\/\/fe3miata.com\/site\/index.php?rest_route=\/wp\/v2\/posts\/255\/revisions"}],"predecessor-version":[{"id":273,"href":"https:\/\/fe3miata.com\/site\/index.php?rest_route=\/wp\/v2\/posts\/255\/revisions\/273"}],"wp:attachment":[{"href":"https:\/\/fe3miata.com\/site\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=255"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/fe3miata.com\/site\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=255"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/fe3miata.com\/site\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=255"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}