OK, I am hesitant to draw any hard conclusions today - got it back yesterday and there are some outstanding issues and some very unexpected behaviors, so I will be discussing further with Alex this Tuesday (their work week is Tue-Sat).
First off, the car dyno'd (w/EBC OFF) at 608RWHP. The acceleration is incredible and I clearly have to be very careful with throttle - twice today in 3rd gear at around 50-60mph I was a little heavy on throttle and started cutting loose on the rear end.
First bad news was that the EBC was not functioning. They suspect the control solenoid and have ordered a new one. Basically, Alex said the wastegate psi was at roughly 6.5, then any attempts to increase boost via the EBC had no effect. Alex and team have apparently installed many of these (they even carry them in stock), so I am going to take that at face value. Another related artifact is that the EBC gauge is reporting extremely high boost values, in the OFF setting. (See below video). At idle, the EBC (bottom gauge) is reading 12.2, then at sustained/steady 2K RPM it is reading >20psi...? WTF is that? At idle until 00:18, then held steady at 2K RPM.
Second issue is that he reported issues with tuning down the rich mix, especially at high RPM ranges. After driving the car, I have noticed what I think is VERY bizarre readings on the AEM Air/Fuel gauge - the gauge readings fluctuate wildly. Even at idle, I know to expect some amount of fluctuation (e.g. on the order of a few tenths), but bouncing from 13-18 at idle? Same exact thing when holding at 2K RPM, 3K, 4K. (Again, see below video, A/F gauge is top gauge).
This is also readily experienced while driving. Under acceleration, the engine is smooth and delivers incredible power, but attempting to maintain any constant RPM, regardless of gear, results in a ton of trailer-hitching (jerking).
The exhaust sounds mean (with the new Stage 2C cam it is fairly lopey), but I am spewing gas. Last two times I sat and idled for 2-3 minutes and turned off the car and REMOVED the key, the car continued running for another 10-20 seconds. (See second video).
Any thoughts?