{"id":14092,"date":"2012-07-17T07:09:26","date_gmt":"2012-07-17T12:09:26","guid":{"rendered":"http:\/\/caddyinfo.com\/wordpress\/?p=14092"},"modified":"2012-07-17T07:09:26","modified_gmt":"2012-07-17T12:09:26","slug":"sts-v-fuel-injectors","status":"publish","type":"post","link":"http:\/\/www.caddyinfo.com\/wordpress\/sts-v-fuel-injectors\/","title":{"rendered":"STS-V Fuel Injectors Added more air, Need more fuel"},"content":{"rendered":"

My 2008 Cadillac STS-V is lightly modded — Spectre Cold Air intake, and Corsa axle back exhaust; STS-V fuel injectors may be next as a supporting mod.<\/p>\n

Each mod so far has proven out on the dyno to improve the performance of the STS-V. The STS-V was factory rated at 469 hp at the crank, and mine is just over 500 hp at the crank now.<\/p>\n

STS-V Fuel Injectors<\/h2>\n

An issue to keep up with as you tune is how the fuel injectors are doing.\u00a0 Mine are running at a duty cycle of 85-86% as we saw on my HP Tuner gauge charts done during the Virtual Dyno baseline runs.<\/p>\n

\"HPTuners<\/a>

HPTuners Gauges Cadillac STS-V First Run Peak HP<\/p><\/div>\n

On a cooler day, with the air more dense, it would run even higher.\u00a0 Above 85% duty cycle fuel injectors can tend to have less precise control of the amount of fuel injected from what I have read.<\/p>\n

There are several different conventional wisdom STS-V fuel injector solutions.\u00a0 Tim C added a Boost A Pump to his V; Jamie went to 60# Ford Racing (Siemens) injectors.<\/p>\n

The Boost a Pump increases and regulates or stabilizes the voltage to the fuel pump to make sure that it provides a steady pressure at all RPMs and to increase the voltage to the pump which increases its output.\u00a0 By increasing the pressure output by 30%, the injectors would then flow more at the higher pressure.<\/p>\n

The fuel system in the STS-V is not boost indexed.\u00a0 The STS-V uses a 58 psi fuel pressure with 42 lb injectors.\u00a0 Using the index tools at Fuel Connector Connection<\/a> for a 550 hp STS-V we would want 50 psi injectors. The Stock 42 lb injectors likely flow 42 lbs at 43.5 psi; at 58 psi they should flow 48.5 psi.\u00a0\u00a0 Increase the pump voltage from 12-14 to 17 volts and the pressure goes up 20-40% to perhaps a steady 70 psi.\u00a0 At 70 psi the 42 lb injectors would act as 53.2 lb injectors.<\/p>\n

Jamie went to 60 lb injectors in his STS-V.\u00a0 This reduced his injector duty cycle from 90% at high RPM to 55% at high RPM.\u00a0 Adding larger injectors requires that the new injector characteristics be set in the tune.<\/p>\n

\"Siemens<\/a>

Siemens 60 lb injectors matched set [click to go to Injector Connection page]<\/p><\/div>I am considering adding STS-V fuel injectors, the Siemens 60 lb injectors as my next mod.\u00a0 Then I could add the boost a pump with the injectors if needed, but I think the injectors will give me margin for my build.<\/p>\n

Speed costs money; how fast do you want to go?<\/p>\n

Have better advice?\u00a0 See a problem with my logic?\u00a0 Am I all wet? Do you agree?\u00a0 Join the conversation in the comments!<\/p>\n","protected":false},"excerpt":{"rendered":"

My 2008 Cadillac STS-V is lightly modded — Spectre Cold Air intake, and Corsa axle back exhaust; STS-V fuel injectors may be next as a supporting mod. Each mod so far has proven out on the dyno to improve the … Continue reading →<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[6],"tags":[],"class_list":["post-14092","post","type-post","status-publish","format-standard","hentry","category-site-info-news"],"_links":{"self":[{"href":"http:\/\/www.caddyinfo.com\/wordpress\/wp-json\/wp\/v2\/posts\/14092","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/www.caddyinfo.com\/wordpress\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/www.caddyinfo.com\/wordpress\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/www.caddyinfo.com\/wordpress\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/www.caddyinfo.com\/wordpress\/wp-json\/wp\/v2\/comments?post=14092"}],"version-history":[{"count":21,"href":"http:\/\/www.caddyinfo.com\/wordpress\/wp-json\/wp\/v2\/posts\/14092\/revisions"}],"predecessor-version":[{"id":14113,"href":"http:\/\/www.caddyinfo.com\/wordpress\/wp-json\/wp\/v2\/posts\/14092\/revisions\/14113"}],"wp:attachment":[{"href":"http:\/\/www.caddyinfo.com\/wordpress\/wp-json\/wp\/v2\/media?parent=14092"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/www.caddyinfo.com\/wordpress\/wp-json\/wp\/v2\/categories?post=14092"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/www.caddyinfo.com\/wordpress\/wp-json\/wp\/v2\/tags?post=14092"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}