2008 ITS/ITA and 240SX (S13). How can I increase Compression? Lighter Flywheel?

[Soravia]

Hi, My 240sx is pretty much stock and I'm reading up on the SCCA rule book.I was hoping I could use some engine modification to improve the power from the KA24DE engine.The rule book for ITS/ITA (where the 240SX falls in) says that the engine compression can be increased by half point (0.5)

l. Manifold and cylinder head port matching is permitted. No material may be removed further than one (1) inch in from the manifold to cylinder head mounting face(s). Carburetor mounting surface(s) shall not be modified, and external dimensionsof the cylinder head or intake manifold may not be reduced to facilitate internal porting. Two piece manifolds are not intended to be port matched at their intermediate point.Valve guide material is unrestricted.Where a factory specification for original cylinder head thicknesscan be proven, a tolerance of .025 inch less than the service limit will be permitted. Under no circumstances may the compression ratio be increased by more than one-half (.5) point. An offset key may be used to return cam timing to the factory specifications. On engines with dual overhead camshafts, this key shall be installed on the crankshaft only.

But it also says that Pistons must be OE.j. Engines may be bored to a maximum of .040 inch over standardbore size. Factory replacement pistons or their equivalent with the exception of diameter shall be used. Cast or forged equivalent pistons shall provide the same dome/dish/valve relief configuration, ring groove width and spacing, pin height relationship,weigh no less than the factory standard bore pistons. Piston rings are unrestricted.

How can I increase the compression from 9.5:1 to 10:1 on the KA24DE w/o having a piston that are the same as OE?

Another thing I want to know is that although the flywheel cannot be drilled or cut to be lightened, can it be replaced with lighter Aluminum aftermarket?

I also didn't mention anything about bumper support core. Can it be replaced?

Thanks.

[crackler]

You might check out SCCA forums, you will probably find some actual IT racers on there that know the rules better than most the people on here. Find the local SCCA region to you and start asking around, I bet you will find some one local that can help you as well.

Sorry I can't be any more help, I am not that familiare with the GCR.

And to help with your flywheel question, typically w the SCCA, at least in soloII, if it is not SPECIFICALLY allowed, than it is NOT allowed.

[nismofly]

comp ratio is changed by shaving the head and changing head gasket thickness

im pretty sure the flywheel and core support both have to remain stock, literally like cracker said the list in the GCR is allowed modifications, if it doesnt say it in there, dont do it