You already have a decent IC product to hold you over until you compile the entire SZ kit. I personally would just wait to do it all at the same time and do it the right way. To answer your question more directly: I seem to recall way back when 2.5" I/O IC's were first being experimented with in the USA, that there were some minimal gains to be had with "only" that change to the IC itself. However, that may have been due to a better overall flowing IC design w/ better end tank design promoting flow. The real gain was when the entire setup was changed to 2.5" collectively. If you leave 95% of the rest of the piping at 2.0" you'll have only marginally changed where the restriction occurs instead of alleviating it. It's easy to get impatient and give in to the desire to get your hands dirty when working on and modifying cars, but in this case waiting until you're acquired the entire kit and realizing/feeling the final result will be far more satisfying. The only time I see doing something incrementally (i.e. inefficiently) is when you're collecting data to help the community make wiser decisions in their purchase priority for the future.
1993 Nissan 300ZX Slicktop (Oxford Gray Metallic) 1991 Nissan 300ZX Slicktop Track-Star 1992 Nissan Skyline GT-R (Gunmetal Gray) - Long Live the Z and Godzirra! - "Love cars. Love people. Love life." - Mr. K. |