{"id":17493,"date":"2015-08-22T08:35:53","date_gmt":"2015-08-22T13:35:53","guid":{"rendered":"http:\/\/caddyinfo.com\/wordpress\/?p=17493"},"modified":"2015-08-22T09:54:28","modified_gmt":"2015-08-22T14:54:28","slug":"cadillac-xlr-virtual-dyno-calibration","status":"publish","type":"post","link":"http:\/\/www.caddyinfo.com\/wordpress\/cadillac-xlr-virtual-dyno-calibration\/","title":{"rendered":"Cadillac XLR Virtual Dyno calibration"},"content":{"rendered":"

Using my initial and second (premium) run data captured from HPTuners, I did some Virtual Dyno<\/a> Analysis (see my initial Virtual Dyno article here<\/a>).\u00a0 First I needed a new custom file for the XLR:<\/p>\n

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

I had run the test data with the top down (worse aerodynamics), and I used a back-to-back wind tunnel test<\/a> of a different car (Miata) to model the degradation of top down as .06 CD.\u00a0 I will want to run virtual dyno tests with top up in the future?<\/p>\n

I created a 2nd custom file to model the XLR with top down:<\/p>\n

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

I edited the .csv saves from Hptuners to only include the acceleration range desired, and loaded both runs.<\/p>\n

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

[click on image to zoom in, back to return]<\/p>\n

I adjusted the SAE conditions for the pressure and temps during the test, 29.1 in\/hg baro and 100F.\u00a0 The car intake air was actually a bit higher.\u00a0 I am not sure this adjustment is quite right — the reference site suggests a dyno adjustment of 4.5% for test conditions.\u00a0 The Virtual Dyno not-SAE – to SAE goes from 251 to 259 or a 3.2% increase.\u00a0 A 4.5% increase would be 262 whp, so not much difference really.<\/p>\n

The results, 249 whp for the initial test, and 259 whp for the known-quality premium fuel test, seem consistent with expectations.\u00a0 259 whp \/ 0.8 transmission losses = 324 hp.\u00a0 Cadillac rated the stock XLR LH2 V8 engine at 320 hp.<\/p>\n

One might conclude the difference between believed-regular unleaded and known premium unleaded in this test case was 10 whp (13 hp).\u00a0 This is similar (9 hp) to what the calculated hp values showed.<\/p>\n

The calculated engine hp vs virtual dyno:<\/p>\n

Initial:\u00a0 2nd gear 293 calc hp x 1.045 conditions adj = 306 hp
\nVirtual Dyno 249 whp \/ .8 trans loss = 311 hp<\/p>\n

Premium: 2nd gear 302.3 calc hp x 1.045 conditions adj = 315 hp;
\nVirtual Dyno 259 whp \/ .8 trans loss = 324 hp<\/p>\n

Or told in the other order:<\/p>\n

Initial: 306 adj hp x .8 trans loss = 244 whp
\nVirtual Dyno: 249 whp<\/p>\n

Premium: 315 adj hp x .8 trans loss = 252 whp
\nVirtual Dyno: 259 whp<\/p>\n

Note in both tests 1st gear calculated hp was higher, and for comparison with Virtual Dyno analysis of the same runs I am using 2nd gear hp data.<\/p>\n

Virtual Dyno depends on consistent, level test area, weights (with\/without fuel for example), and conditions for comparable results.\u00a0 It has however been tested over and over to be consistent with dynojet results when done with proper care.<\/p>\n

My conclusion is that I need to do a few more captures of consistent test data for Virtual Dyno use, but the configuration files I have predict results consistent with my other indicators.<\/p>\n

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

Using my initial and second (premium) run data captured from HPTuners, I did some Virtual Dyno Analysis (see my initial Virtual Dyno article here).\u00a0 First I needed a new custom file for the XLR: I had run the test data … 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":[779,564,324,189,845,299],"tags":[],"class_list":["post-17493","post","type-post","status-publish","format-standard","hentry","category-hp-tuners","category-test-drive","category-test-gear","category-test-info","category-virtual-dyno","category-xlr-cadillac-models"],"_links":{"self":[{"href":"http:\/\/www.caddyinfo.com\/wordpress\/wp-json\/wp\/v2\/posts\/17493","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=17493"}],"version-history":[{"count":8,"href":"http:\/\/www.caddyinfo.com\/wordpress\/wp-json\/wp\/v2\/posts\/17493\/revisions"}],"predecessor-version":[{"id":17504,"href":"http:\/\/www.caddyinfo.com\/wordpress\/wp-json\/wp\/v2\/posts\/17493\/revisions\/17504"}],"wp:attachment":[{"href":"http:\/\/www.caddyinfo.com\/wordpress\/wp-json\/wp\/v2\/media?parent=17493"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/www.caddyinfo.com\/wordpress\/wp-json\/wp\/v2\/categories?post=17493"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/www.caddyinfo.com\/wordpress\/wp-json\/wp\/v2\/tags?post=17493"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}