Hey mate,
i dont think they are high flow (seeing they are ceramic..) ive changed mine to HM s/s 2.5" High Flow 200cell ones.. very happy
i can tell you that the outlet of the stock ones are 2.25"
ceramic core cats, 400 cell per sq inch (not high flow), outlet 2.25"
400 cpsi.....ceramic....ARE considered to be high flow, but not really in comparison to some of the good stuff that is reasonably priced on the market now
You'd pick up max, 1 or 2 rwkw, I'd only consider getting a pair for the sound or if it was pushing serious HP.
Kuzman's Supercharged SV6 - MACE TUNED
agree with kuzman, no point really unless you purchase a pair of 200 cpsi for better sound IF you do extractors etc at the same time
100 cpsi are too free flowing and will sound raspy
not too much to be had in terms of gains though