Originally Posted by TypeT
^ but how "heavy build" you can do if you only can tune/use VAFC?
Your tuning capabilities are obviously going to be limited if you maintain ATTS function - the Apex'i VAFC allows SH owners to adjust where VTEC engages based on RPM increments, and also allows the reduction or addition of fuel based on RPM and Throttle % measurements.
While the VAFC does not allow for the adjustment of spark timing, it still can be a very useful tuning device (when in the proper hands) and it isn't uncommon to find SAFC users boasting 300-400whp turbocharged cars throughout the world.
Most people on the forum will tell you, however, to choose to either tune and add performance modifications to your engine, or keep ATTS. Not both. The Skunk2 manifold will fit on an SH prelude but it will eliminate your EGR, therefore throwing a check engine code unless your system is run on an aftermarket standalone or chipped P-series ECU (which also will disable ATTS function).