VTEC is a dual intake and exhaust cam system in which both cams have two set of lobes (one set with more lift and duration than the other) that the corresponding intake and exhaust valves follow. VTEC activates at 4400 rpm's in the GSR and at 5700 rpm's in a Type R. When it activates, the intake and exhaust valves switch over from the smaller cam lobes to the larger cam lobes, allowing more air to pass through the engine which greatly improves intake flow velocity and volume to create more power in this upper rpm range. As previously mentioned, 28 more hp in a GSR than the LS, RS, GS, and SE Integras, and the Type R has 53 more hp.
btw, USDM Type R's have 195 hp, JDM Type R's have 197 hp.
The only Integras with the LSD is the Type R.