I would be interested in knowing which company you found making S/C for the LLT (or any turbo kit for that matter). Or if you have found boards with members sporting these kits where they offer their opinions, knowledge, experience and times with these.
All I have found are S/C kits for the VZ V6 (i.e. the LY7; the non-DI version of the LLT... or the other way around: the LLT is the DI version of the LY7
)
I have no way of verifying this as this is just information taken directly from their webpages, but apparently CAPA has made 440kW (590hp) out of the LY7 @ 11 boost with a Vortech T-trim kit. It is unclear if this is at the motor or at the wheels (they don't specify) and as to add more confusion... the dyno graph says HP instead of kW whereas all the other graphs say kW (yet the description says kW
). Some of their numbers may look low, but we need to remember the VZ V6 (LY7) started at ~175kW (235hp); the LLT starts at 227kW (304hp).
References:
http://en.wikipedia.org/wiki/GM_High_Feature_engine
http://www.capa.com.au/kits_holden_vzv6.htm