I have been testing my 2007 Cadillac XLR with the LH2 4.6L DOHC V8 engine to establish a baseline prior to any mods or tuning.
Today the air was a bit cooler, although not as much as I had hoped. HPTuners VCM Scanner recorded a 97F intake air temp, and 29.83 barometer during the test. For safety, testing is done in 2nd gear which is not optimal — it should be done in a 1:1 ratio or as close as possible. I am using Virtual Dyno to convert captured export data from hptuners to a on-road dyno result.
[click to zoom in, back to return]
The red and blue runs are both from today, and run within 6 minutes of one another on our 2-test area cycle. I was hoping to see a bit more whp in the cooler air, but I suppose 97F not all that cooler than 104F from the prior tests.
This second chart shows today’s 2 runs in yellow and green vs prior runs in red and blue. Corrected for temp and gas, the results seem fairly consistent at least.
All runs are using current method, which is drive to a known point with transmission manually selected to 2nd gear, then wide open throttle until fuel stop at redline. Rinse, repeat.
Info Video about this type of testing
Calculated hp/torque for the LH2 in this test peaks 308 hp @ 6635 rpm, and 296 lb ft at 4503 rpm.
Today’s tests appear to be consistent with prior tests.