brianthemagical 1 Posted April 17, 2007 as above, what would be a desirable dcr to go for on a xu9 8v, standard injection, running bp ultimate/98ron petrol. it's a road car so i still want a degree of reliability and to not be on the limit of the engine. everything is standard component wise. thanks. Share this post Link to post Share on other sites
petert 607 Posted April 17, 2007 Have you seen this site and downloaded the calculator? http://www.empirenet.com/pkelley2/DynamicCR.html Share this post Link to post Share on other sites
brianthemagical 1 Posted April 17, 2007 (edited) thanks, i was hoping you'd reply. i have a calculater and have read a lot of stuff but i wanted to know what was recommended for the xu9 as in my first post. i'm not in a position to experiment so would like some experiance to go on. edit:from the aove link (which i assume is american and i have read preaviously) i don't know what ron there 'gas' is and between 7.5 and 8.5 is a bit too vague. thanks again. Edited April 17, 2007 by brianthemagical Share this post Link to post Share on other sites
petert 607 Posted April 17, 2007 I think 91 mon is approx. 98 ron. Start be calculating the std. setup. You might be surprised to see how good it is. I'd be aiming for 8.0-8.2. An XU10J4 runs at approx. 8.1 from memory. Share this post Link to post Share on other sites
brianthemagical 1 Posted April 17, 2007 (edited) thanks. on the above calculator i got scr at 9.7 and dcr at about 8.8. i thought it was on standard cam timing but maybe i got confused when inputting the data. the head and block have been skimmed and i was calculating with a 1mm HG. I was planning on varying the thickness of the HG to alter the cr. thanks again. Edited April 17, 2007 by brianthemagical Share this post Link to post Share on other sites
