I just finished helping my buddy install a procharger on his 2008 C6 (E38). He also installed an ECS blower cam as well as methanol injection. Running stock injectors but he has a set of SD 60lb injectors to install at a later date. Car also has Long tube headers, no cats, borla cat back and he has a LC-1 wideband.
The car wants to die when the clutch is pressed down, say when coming to a stop (idles ok after start up). The RPM's drop way way down and it either struggles and recovers or totally dies. I'm trying to decide what to modify to fix the problem. Only table I've modified is the Start Up airflow to get it to crank. Not sure if it's the cam or the extra drag of a supercharger causing it to die, probably both.

I have tuned many LS1 cars but never messed with the E38 PCM. Too much **** is different in the damn E38 PCM.

 

Not much to help with without a tune. What tuning suite are you using?
The E38s are completely different animals.
If you want you can PM me. I've done about a dozen of them so far.

 

He is using HPTuners. I can't seem to attach the damn tune here in tech. Here is his link from the HPTuners forum or pm me your email address and I would email you his tune. http://www.hptuners.com/forum/showthread.php?t=18014