I hear you on the warranty but that will not hold me back once some of these tuners get some experience under their belts and have a history of success. I have however heard that all most of the drivetrain supports 550hp pretty easily that there is an issue with not enough fuel being available without changing some parts? I briefly looked at Hennessey's package though and he makes no reference to an upgrade that would increase fuel availability and I would think they know what they are doing but I have never dealt with them.
yep, these guys are finding you can get to about 550whp before the stock fuel system becomes inadequate. weaponX is working on some camshafts to address this; they have a test platform that is running in the 10s at the strip. guys are having issues in the upper gears at max throttle, high speed.
one guy modded his, made youtube vids of the dyno, etc. i think he was at the limit of the stock fuel systems and cams. he had detonation in cylinder 6 and basically tanked the motor. i don't think he listed what he was going to have to replace, but he posted a pic of the slip the dealership handed him- powertrain warranty voided. GM also sent the youtube vids of his dyno testing to the dealership's service dept.
i don't think this guy cares, he will just shell out the $$$ to fix it, plus i think he's pretty plugged in with the shop doing the mods.
it's crazy how much power the OEM config leaves on the table. i think he was only running a tune, intake, and exhaust and he had some seriously impressive dyno results.
weaponX is going to have a 600+whp package soon. according to them, this motor will make that with ease.
that henessey package looks cool. i emailed him and asked him to put a vid up on his youtube channel and he replied and said he was already planning to do a vid of the next build. should be cool. i would just wonder what he actually covers and how it would work out if you didn't live in TX.
sadly, mine is a lease and i need to leave it OEM.
in the end, i guess it depends on how much money you have. you play, you pay. if i was loaded and my car was a purchase i'd do it. but i'm not loaded, and my car is leased.. and since this is a first year model car with several issues, i'd hate to have a legitimate (non-mod related) issue denied warranty coverge because i tuned the ECM. this is my daily driver.