2011 C6 Performance Upgrades
I own a 2011 C6 coupe with the LS3 with dual mode exhaust. I have added headers, Xpipes with hi-flow cats and a hi-flow air intake. At this time I do not plan on supercharging the engine, although it is a possibility in the future. I am thinking about a 102mm intake manifold, a TB to compliment the manifold (TB must be electronic/drive by wire). It has been recommend to change out OE fuel rails with fuelk rails that will take advantage of the increase fuel/air mixture. If I upgrade the fuel rails then I need new fuel lines. My goal is to increase my LS3's HP to be close to 500HP without supercharging. I know Lingenfelter offers the intake manifold, but I do not know about the rest.
LS3 Intake Manifold vs 102 MM Fast Intake
In engine dyno testing here at LPE we have not seen much improvement on smaller displacement engines with conservative camshafts by adding the Fast intakes. We would only suggest the 102mm with a 427 CID or larger and a big camshaft. If you are keeping it stock cubic inch then the LS3 intake port matched to the cylinder heads and a ported and polished stock throttle body would add the same that the 102 intake would add for a lot less money.