the us version uses k20c where as jdm uses f20ci and redline @
10k. the reason is the low fuel octane they have in the us making
it necessary to have a slight different engine block and
configuration. althou f20c is similiar to the accord's engine, it's
on a totally different dimension (more like a f1 engine, short beam
and short stroke alowing higher revs). with a spoon block, the
redline are rise to 12k (fyi it's the same donk they use in the
spoon jgtc s2k) reason to this is it's a much heavier and stiffer
block which allow a more stable, higher revving engine.
ummm wrong wrong wrong and wrong again 
the us spec s2000s use the f20 for the earlier specs and more
recently the f22 with a 2.2 litre engine(obviously) for more
torque. everywhere else still has the f20 in the S2000s (at least
in japan, most of euro and oz anyways)
The K-series engine in the RSX is a direct descendant (brother?) of
the F20C. The bore spacing, block design, cylinder head design,
even the oil filter location are the same. You can actually
interchange several cylinder head parts between the F and K
series.
The engines aren't the same, but they're close
s2000s max rpm is about 9000rpms(not 10k) but the cluster has 10k
on it, you never get there on a stock s2000 anyways
the us spec INTEGRA RSX gets the k20c with produces 200 hp @
7400rpms
the stock redline never reaches 10k for the f20 (jap spec or not)
but jap spec produces more hp (250 compared to 240) due to higher
octane fuel in japan
and no spoon does not participate in the JGTC series
Super Taikyu endurance is what the spoon car does
i have never seen an s2000 in the JGTC series , never heard of one
anyways
ususally they would use the NSX for honda teams
and pls do some research before posting an answer to a technical
question, i'm quite surprised at how much you actually know about
S2ks considering your user name 
do you get your info from initial d acrade stage or soemting ? lol
