Tonight I setup my test laptop with HP Tuners in the 2007 Cadillac XLR to see if it would all play together — with some success.

I used the scanner profile that is setup for my 2008 STS-V,  which makes for good comparison but perhaps higher scales than the XLR needs.  The XLR was well heat soaked, and it was warm here in Texas still even though evening time.  Intake air was 95 F outside, 100 F coming into the engine, and 135 F in the manifold.   Plano is at 600 ft elevation above sea level.

What I see in this initial scan is a) it works at all and b) the XLR PCM calculated that the engine output was around 301 hp in 1st gear at 5734 rpm. It stayed around 300 hp from there to when it shifted.   The XLR LH2 V8 is rated at 320 hp at 6400 rpm under ideal test conditions at sea level, 70 F etc.

Max first gear calculated torque was 290 lb ft at 4572 RPM.  The LH2 is rated at 315 lb ft of torque at 4400 rpm under SAE test conditions.

320 hp LH2 Rear-wheel Drive Variant

On first blush, I am pleased that I got the test gear working, and the HP tuners can talk to the XLR,and I can capture data and post it.  Now I can study what it means lol.

This is a graph created from a data export from hptuners vcm scanner of the delivered torque, and derived calculated hp.