In Japan the "240 SX" is actually the 200 SX and comes with a SR20DET Turbo 2.0L 4 Cylinder that is very accepting to higher boost and lots of easy upgrades... a number of the japanese engines of the late 90's are very strong and very easy to upgrade.. the SR20DEt is one of these and just happens to bolt right into the 240 SX (240 because its engine is a 2.4L.. same as the 180SX had a turvo 1.8L and the 200SX had a turbo 2.0 L in japan) .. its a simple swap.. relatively cheap.. and the engines are readily available.

a number of car shops locally specialise in the swap.. and Enthalpy at one time had the most HP out of a stock bottom end SR20DET (539 HP if i rmember) .. now in a 2400-2500 lb car.. that makes for some sereous speed