I was wondering: If I go with the S280 with stock fueling, tuned for 91OCT, can I stick with the stock cat? And if so, what would be the ramifications on things like spool speed, max torque/hp?
I know that some guys have gone forward with the S280 with stock cat, so it's feasible, but there's no feedback on what's being left on the table if you don't upgrade to the high flow cat. Trying to get myself in or out of a case of mightaswell-itis.
Existing mods: High flow filter, whoosh induction + crossover, whoosh V3 intercooler, flowmaster 2.5" catback.
Either way I still need to install B6s all around and get new summers and winters, so still in the planning stages for this upgrade.