![\"XLR](\"http:\/\/caddyinfo.com\/wordpress\/wp-content\/uploads\/2015\/09\/XLR-Tune5B-to-Tune-5.png\")
<\/a><\/p>\nToday’s run is in Blue, and we are comparing to the Tune 5 run in red.\u00a0 What I see is the runs are very close.\u00a0 Today’s somewhat better torque may be an (additional) effect of cooler air, or it may be helped by the PE ramp up.\u00a0 We’ll see how other runs look — certainly I don’t see any disadvantage from the higher PE ramp.<\/p>\n
The calculated HP peak was at 6554 RPM.\u00a0 ECT 194F, ambient 88F, Intake air 90F, MAT 115F.\u00a0 Some IAT retard.\u00a0 Peak advance ~26.5 degrees.<\/p>\n Madtuner.com<\/a> offers a tune for the LH2; they did work on a 2005 STS in 2012 and showed this dyno chart for before \/ after:<\/p>\n This looks very similar to what I am seeing with the LH2 in my XLR.\u00a0 They had some glitch in the base tune, but I am looking at the shape of the before & after curves — the HP peaks at 5400 or so and is flat until 6000.\u00a0 They stop the scan at 6000 rpm for some reason — I suppose because the engine wasn’t making more power past that.\u00a0 They don’t mention the specifics of their tune.<\/p>\n Cadillac XLR 320 hp picks up 12 whp with Magnaflow catback<\/p><\/div>\n The Magnaflow performance exhaust for the Cadillac XLR shows a similar shape in the before and after — HP peaking near 5400 RPM and dropping to past 6000 rpm.<\/p>\n 320 hp LH2 Rear-wheel Drive Variant<\/p><\/div>\n GM powertrain showed the LH2 continuing to improve hp until 6400 rpm.\u00a0 Redline is at 6700 rpm.\u00a0 Note that the GM plot is an engine dyno, and the Madtuners and Virtual Dyno plots are hp at the rear wheels, so we expect them to be different due to drivetrain, friction,\u00a0 and aero losses.\u00a0 The part I am considering is the shape of the curve — the engine dyno showed that the LH2 makes a bit more power from 5500-6400 RPM.\u00a0 To be fair, it is not on the same up-slope as 1000-5500 RPM.<\/p>\n Today’s test added to the Tune 5 baseline.\u00a0 The Madtuner result is supportive that there is more to be gained here somewhere.\u00a0 The Madtuner experience closely mirrors my results and varies from the engine dyno.\u00a0 More testing to follow.<\/p>\n If you have ideas, suggestions, encouragement, or advice please hit Reply!<\/p>\n","protected":false},"excerpt":{"rendered":" Today’s road test is a repeat of the previous test to add to the baseline for Tune 5.\u00a0 The only change from previous was to decrease the TUTD shift speed by 1 mph to 81, and to change the PE … Continue reading <\/a><\/p>\n<\/a><\/p>\n<\/a><\/a>