You're not gonna max the voltage with just an intake. It's something else. Check for leaks, clean the MAF, replace the pcv valve, fuel filter, clean injectors, spark plugs, plug wires, coil,etc.
98.5 SVT
91 Escort GT (almost sold)
96 ATX Zetec (i brake to watch you swerve)
FS: SVT rear sway bar
WTB: Very cheap beater
CEG Dragon Run - October 13-15