OK, 2 questions, what do you mean by crackign secondaries, and will it hurt my car to replace the catalytic converter with a straight pipe, that and the resignater? Sorry abotu the spelling, i suck!! LOL
98 Contour SE v6 ATX Mods: Ractiv Cold Air Intake Ractiv Dual Tip Exhaust FlowMaster Catalytic Converter Boshe Platinum +4 Plugs Numerous Interior Mods Stereo: 2 1000Watt Lanzar Subs 1400 Watt Lanzar OptiDrive Amp Monster Cable throughout Pioneer DEH 7200 CD Deck
There are two intake ports for each cylender that bring air into the engine. The primary ports are always open and air flow is controlled by the throttle body. The secondary ports (the secondaries) are closed below ~3750 RPM by using a butterfly valve. Once you reach 3750RPM, the butterflies open allowing air to flow through the secondaries (after the throttle body). The air coming in through the primaries and secondaries combined produces the power to reach redline. Cracking the secondaries is what we call it when we turn a "stop screw" so that the secondaries intake valves cannot fully close. This allows more air to enter the engine at any given point. Also, it's said to keep gunk from building up since they're always open just a bit and air is always flowing. Supposedly helps lower end torque just before 3700RPM's without comprimising any performance.
Putting in straght pipe for the cat and resonator will definately be louder but shouldn't mess up your car, other than it's ability to pass an emmisions test. Cracking the secondaries too far can hurt low end performance on fairly stock motors, so you really want them held open just a "crack".
