2002-2004 Acura RSX Type-S has the K20A2 engine * Displacement: 1998 cc * Compression: 11.0:1 * Power: 200ps/197hp (147kW) @ 7400rpm * Torque: 142ft·lbf (193N·m) @ 6000rpm * Redline: 9800rpm2002-2006 Acura RSX (base) has the K20A3 engine * Displacement: 1998 cc * Compression: 9.8:1 * Power: 160 hp (119 kW)* (119 kW) @ 6500 rpm * Torque: 139 @ 5000 rpm2002-2006 Honda Integra Type-R has the K20A engine * Displacement: 1998 cc * Compression: 11.5:1 * Power: 217 bhp (220 PS, 162 kW) @ 8000 rpm * Torque: 152 ft·lbf (206 N·m) @ 7000 rpm * Redline: 8500 rpm2005-2006 Acura RSX Type-S has the K20z1 engine * Displacement: 1998 cc * Compression: 11.0:1 * Power: 207 hp (154 kW) @ 7800 rpm (SAE net J1349 Rev 8/04) * Torque: 141 ft·lbf (194 N·m) @ 7000 rpm (SAE net J1349 Rev 8/04) * Redline: 8100 rpmDon't get the base. You can get a lot more power by mods (even simple bolt ons) from the Type-S engine than the base one. The A2,Z1 and A are a lot similar with differences such a exhaust, cams, pistons etc. Other than the engine, the S also comes with a host of other features such as Bose CD changer with woofer, tighter suspensions etc. Even though the K20A generates the most hp and revs the highest it's also got the highest compression ratio which means you'll need 94 octane. For everyday use it does become rather inconvenient. Regardless, if you are modding your car just get whatever makes you happy. That's the most important thing.
en.wikipedia.org